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760 Cards in this Set
- Front
- Back
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What is the role of percutaneous cholecystolithotomy?
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It's increasingly used in elderly and high-risk patients unsuitable for laparoscopic cholecystectomy. It is successful in achieving stone clearance but is associate with a high incidence of recurrent stone formation.
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If at laparoscopy, one unexpectedly encourters an acutely inflamed pus-filled gallbladder with multiple adhesions such that the anatomy around porta hepatis is obscured and cholecystectomy is deemed unsafe, what therapeutic laparoscopic procedure could be done?
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The fundus of the gallbladder is exposed, a trocar is inserted into the gallbladder and the contects aspirated. A drainage catheter can then be inserted into the gallbladder and the operation concluded.
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Hepatic cirrhosis is a major risk factor of morbidity and mortality in patients undergoing elective cholecystectomy. What are the major peri-operative causes of death associated with this condition?
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The 2 major causes of death are intra operative bleeding and post operative hepatic failure.
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What are sites of bile duct leaks after cholecystectomy?
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Main duct, cystic duct remnant (most common), a gallbladder leak due to trauma to a duct during dissection of the gallbladder from the liver, clipping of the right hepatic duct proximally leaving the hepatic end free to drain and damage to the duct of Luschka.
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What conditions justify cholecystectomy in cirrhotics?
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Symptoms are severe or the cirrhosis is well compensated.
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What is the common cause of death after cholecystectomy?
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Most deaths are related to cardiac disease, particularly myocardial infarction.
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T/F: The presence of acute cholecystitis is a contraindication to laparoscopic cholecystectomy.
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False
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In a patient with a recent bile duct injury, what is the role of abdominal ultrasound?
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It may demonstrate dilated intra/extrahepatic ducts, fluid collections of abscesses in the perihepatic region. It may also be helpful in suggestion changes of cirrhosis, splenomegaly and portal hypertension, which are particularly important considerations in planning an intervention in any such patient.
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What are the complications of laparoscopic cholecystectomy performed for acute cholecystitis?
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The main intraoperative complications are perforation of the gallbladder, bleeding from the liver bed or cystic artery and iatrogenic injuries to the bowel or vessels due to unclear anatomy. The main postoperative complications are local wound hematoma or infection and systemic hematoma.
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What are situations in which the bile duct size is normal in a patient with bile duct injury?
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Presence of a biliary fistula, long-standing partial obstruction with biliary fibrosis and cirrhosis.
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What is the most important cause of bile duct injury during laparoscopic cholecystectomy?
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Aberrant biliary anatomy found in about 3% of patients.
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Some patients undergoing laparoscopic cholecystectomy may have common bile duct (CBD) stones that may not be suspected at time of procedure. What is the natural history of these unsuspected CBD stones?
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They are detected in 1.2% to 14% of patients undergoing cholecystectomy. A number of reports have documented the spontaneous passage of CBD stones into the duodenum. Only 0.5% to 0.8% of patients undergoing laparoscopic cholecystectomy will subsequently return with problems due to unsuspected CBD stones. These patients can easily be managed by endoscope retrograde cholangiography.
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In a patient with a recent bile duct injury, what is the role of abdominal ultrasound?
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It may demonstrate dilated intra/extrahepatic ducts, fluid collections of abscesses in the perihepatic region. It may also be helpful in suggestion changes of cirrhosis, splenomegaly and portal hypertension, which are particularly important considerations in planning an intervention in any such patient.
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What are situations in which the bile duct size is normal in a patient with bile duct injury?
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Presence of a biliary fistula, long-standing partial obstruction with biliary fibrosis and cirrhosis.
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What is the most important cause of bile duct injury during laparoscopic cholecystectomy?
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Aberrant biliary anatomy found in about 3% of patients.
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Where do biliary fistulae commonly arise after laparoscopic cholecystectomy?
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The cyctic duct stump.
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In some patients, bile duct injury with stricture formation may appear several months after laparoscopic cholecystectomy. What is the mgmt at this time?
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Prompt endoscropic dilatation of such strictures may lead to resolution without the need for surgical intervention.
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What is the significance of cholecystohepatic ducts?
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They present in 3-5% of cadavers, may be transected during laparoscopic cholecystectomy and are another source of biliary leakage.
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What factors prevents spontaneous closure of postoperative biliary leaks?
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Most heal spontaneously. The presence of distal biliary obstruction secondary to a stone or stricture contributes to the formation of leaks and bilomas and prevent spontaneous closure.
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T/F: ERC should be performed routinely prior to laparoscopic cholecystectomy.
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False. pg 34
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In what situation should preoperative ERC be considered prior to cholecystectomy?
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Patients with severe gallstone pancreatitis or acute cholangitis, those having a high probability of having common bile duct stones or when there is a significant possibility of other pathology.
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What is the probability of finding CBD stones using this 4-predictor model?
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Ranges from 18% (no predictors present) to 94% (all 4 present). When tested prospectively in patients suspected of having CBD stones, this model demonstrated that CBD stones were present in only 8% with none of the 4 predictors compared to 66% with two or more.
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As independent parameters, which of these predictors has the highest positive predictive value?
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Increased bile duct diameter or presence of stones on ultrason. had the highest positive predictive value for detecting a cbd stone (64% and 78%, respectively)
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T/F: A recent history of pancreatitis correlates strongly with the presence of CBD stones.
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False. Except in cases of severe or persistent pancreatitis. In a recent study, cbd stones were present more frequesntly in groups with severe (63%) pancreatitis compared to the mild group (26%).
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What is the best approach to take in patients with severe gallstone pancreatitis?
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Early cholecysteectomy with common bile duct exploration is not the best approach in the setting of servere gallstone pancreatitis due to high morbidity and mortality. ERCP with sphincterotomy is the therapy of choice in this situation.
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In a patient who has gallstone pancreatitis, when should cholecystectomy be performed?
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During the same hospitalization once the clinical signs of pancreatitis have resolved.
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What should be done if small, unsuspected stones are visualized in the common bile duct during intraoperative cholangiography?
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Nothing. It is believed that most small stones will pass spontaneously without symptoms or complications. It is estimated that only 10% of small, unsuspected stones will become symptomatic. If they become symptomatic, ERC and endoscopic sphincterotomy with stone extraction can be performed.
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T/F: The finding of a localized fluid collection or ascites in a patient who has recently undergone a laparoscopic cholecystectomy requires immedicate surgical intervention.
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False. Postoperative ascites and edema of the gallbladder fossa on CT scan or ultrasonography is a normal post operative change and has been reported in 19% and 22% of patients, respectively.
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What non invasive test is most useful in detecting post-cholecystectomy bile leaks?
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Hepatobiliary scintigraphy is highly sensitive and specific.
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What confirmatory tests should be performed if a biliary leak is found on scintigraphy?
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Cholangiography, via an endoscopic or percutaneous approach, will usually confirm the presence of a leak, detect coexistent biliary strictures or retained stones and allow for the appropriate therapeutic procedure.
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T/F: A CT scan can differentiate between the various types of fluid collection.
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False. They have limited ability to differentiate bile from blood, ascites, pus, or lymph.
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What is the best approach to take in a patient who has a postcholecystectomy bile duct injury and presents with biliary peritonitis?
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Usually caused by infected bile. External percutaneous drainage is the best initial approach. Definitive repair of the lesion can be done after the infection has been treated.
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What is the first line of investigation in a patient who presents early after laparoscopic cholecystectomy with jaundice?
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endoscopic retrograde cholangiography.
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In a patient with a bile duct injury following cholecystectomy, what is the procedure of choice if the distal CBD is found to be occluded by ERCP?
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If its occluded or transected and continuity to the proximal duct is lost percutaneous transhepatic cholangiography (PTC) is necessary to outline the proximal ducts and to provide external biliary drainage. Surgery will eventually be necessary.
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What are presenting symptoms in patients who have (bile duct) Type A injuries?
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66% of these patients present with a symptom complex of pain and fever. In about 33% of these cases, the presentation is that of an external bile fistula. Patients with Type A injuries are almost never jaundiced.
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What is the optimal approach to take in patients who present in the early post-cholecystectomy period with abdominal distension suspicious of biliary leak?
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A CT scan or ultrasonography of the abdomen is used to search for intraperitoneal fluid. If a bile collection is present, it may be drained percutaneously. Biliary scintigraphy is then done to determine if a leak persists followed by therapeutic ERC if a leak is found.
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What is the treatment of choice for (bile duct) Type E injuries?
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Roux-en-Y hepaticojejunostomy
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In a patient with suspected gallstones but atypical symptoms, what are the most appropriate initial investigative procedures?
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Endoscopy and/or UGI contract radiography is performed to exclude disorders such as esophagitis or peptic ulcer disease.
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Patients may have a variety of postoperative symptoms following cholecystectomy. In what group is investigation most likely to reveal a cause?
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Common postoperative symptoms include flatulence, bloating and right upper quadrant and epigastric pain. A small % present with severe abdominal pain, jaundice or emesis. Investigation in the latter group is more likely to reveal a distinct treatable cause.
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What are common clinical presentations of gallstone disease during pregnancy?
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Worsening biliary colic and acute cholecystitis are the most common clinical presentations. Jaundice and actue pancreatitis as a result of choledocholithiasis are rare.
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T/F: Pregnancy is a contraindication to laparoscopic cholecystectomy.
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False. Improvements in anesthesia and tocolytic agents have made cholecystectomy safer during pregnancy. Complications such as spontaneous abortion and preterm labor are more common in operated women in the first and third trimesters of gestation, respectively. Laparoscopic cholecystectomy can be performed safely in a carefully controlled clinical setting.
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What are the two types of Mirizzi's syndrome?
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Type I - The hepatic duct is compressed by a large stone that has become impacted in the cystic duct or Hartmann's pouch. Associated inflammation may contribute to the stricture.
Type II - the calculus has eroded into the hepatic duct, producing cholecystocholedochal fistula. |
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What is the importance of recognition of the presence of Mirizzi's syndrome?
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It's important during difficult cholecystectomy to reduce the likelihood of hepatic duct injury.
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What is the ultrasound picture in Mirizzi's syndrome?
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Ultrasound revelas gallstones with a contracted gallbladder and moderate intrahepatic ductal dilatation.
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What are the x-ray findings in gallstones ileus?
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An intestinal gas pattern compatible with intestinal obstruction in most patients; pneumobilia is half of all patients; and a visible aberrant gallstone in a minority.
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What is the size of the gallstone that causes gallstone ileus?
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Usually >2.5 cm in diameter.
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How does gallstone ileus present?
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It shoudl always be considered in an older patient with intestinal obstruction. It sometimes has a prior history of acute cholecystitis, but most of th estones erode slowly through the gallbladder and the symptoms may be minimal, especially in the elderly.
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What are the characteristics of small bowel obstruction in gallstone ileus?
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As it progresses down the length of the gut, it intermittently obstruct the lumen. Characteristically, complete obstruction occurs in the ileum where the lumen is the narrowest.
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What happens when the gallbladder perforates into the adjacent intestine during an acute attack of cholecystitis?
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The acute attack often subsides as the inflamed organ is decompressed. If the gallstones are completely discharged and are small enough to pass rectally, an uncomplicated cholecystoenteric fistula results. However if stones are still present in the gallbladder or common bile duct, chronic symptoms may arise.
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What are the most common sites of cholecystoenteric fistula?
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In descending order of frequency, the duodenum, hepatic flexure of the colon, stomach, and jejunum.
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What investigations are useful for diagnosing cholecystoenteric fistula?
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Plain abdominal x-rays may show air in the biliary tree. Barium studies often reveal the site of communication. The gallbladder does not opacify on oral cholecystography. Ultrasonography of the gallbladder can detect air in the biliary tree but not the site of the fistula. CT scans are less useful in detecting gallstones and fistulae; although they may show air in the biliary tree.
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What problems can be caused by a cystic duct remnant in a patient who has undergone cholecystectomy?
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In some, the cause of postcholecystectomy symptoms has been attribute to pathology in the cystic duct remnant. The described abnormalities include cystic duct stones, fistulae, granulomas, or neuromas. ERC is useful in delineating biliary anatomy in patients with suspected cystic duct remnant pathology. Treatment is cystic duct excision.
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What tests should be performed in a patient with postcholecystectomy symptoms?
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CBD stones are the most common cause of postchol. symptoms. Liver function tests, particularly alkaline phosphatase, may be elevated. Ultra sonography may reveal indirect signs, such as a dilated bile duct, but direct visualization of the stone is uncommon. ERC is an important diagnostic took with which to confirm the presence of ductal stones and exclude the presence of bile duct stricture or tumor.
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What other biliary cause of postcholecystectomy symptoms should be considered when CBD stones and cystic duct pathology have been ruled out?
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Sphincter of Oddi dysfunction.
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Name 3 patterns of presentation in bile duct injury?
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Complete occlusion of the bile duct with rapid development of jaundice in the post operative period; bile peritonitis; and partial duct obstruction with intermittent episodes of pain, jaundice or cholangitis usually w/in 2 yrs of the cholecystectomy.
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When is surgery recommended for benign biliary strictures?
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Complete ductal transection, failed previous repair and failure of endoscopic therapy.
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T/F: It is possible to differentiate between choledocholithiasis and bile duct stricture on the basis of symptoms.
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False.
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What radiologic evaluations should be considered in a patient with a suspected bile duct stricture?
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The eval should begin with ultrasonography to identify ducts and/or a subhepatic fluid collection. In the early postoperative period, a Tc-labeled radionuclide scan may expeditiously and noninvasively demonstrate patency of the biliary tree and exclude bile leak. If these studies suggest bile duct injury, ERC is indicated to define and possibly treat the lesion.
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If laparoscopic bile duct injury is suspected, what is the earliest time when an ERCP can be done?
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If its suspected immediately following laparoscopic cholecystectomy, diagnostic and therapeutic ERC can be performed as little as 6 hours postoperatively.
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How is an intrahepatic bile leak treated?
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These can be treated with short stents positioned below the leak.
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What are characteristics of biliary type pain?
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It is not colicky but rather a steady right upper quadrant or epigastric pain. The duration of pain is commonly 1-5 hrs and is usually nocturnal. A postprandial association is also uncommon. Biliary pain is usually relieved by narcotics and the majority of patients experience pain at a clock-time that is characteristic for each patient.
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What are consquences of stricture development following injury to the bile duct due to laparoscopic cholecystectomy?
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Cholangitis, biliary cirrhosis, and eventual liver transplantation.
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What options are available for removal of cbd stones if preoperative ERC failes?
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If the stones are small and the laparoscopic surgeon is skilled in laparoscopic bile duct exploration, an attempt at this treatment procedure is made. If it is not successful or large stones are found, an open bile duct exploration is the treatment of choice.
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What is the approach to a patient with acute suppurative cholangitis?
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These patients have a very high mortality rate (10-50%) when operated on emergently. Energency endoscopic decompression has a lower morbidity and mortality than either emergent percutaneous or surgical decompression. The decision to perform endoscopic phincterotomy or place a stent or nasobiliary drain depends on the severity of the patients clinical condition at the time of the procedure.
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What aberrant anatomy of the hepatic duct can lead to its misidentification as the cystic duct?
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In 20% of cases, the right anterior and right posterior hepatic ducts do not joint to form the right hepatic duct (RHD). Instead, the right posterior hepatic duct (RPHD) joins the left hepatic duct proximally and the right anterior hepatic duct (RPHD) joins it distally. In this situation, the RPHD is misinterpreted as the RHD and the RAHD as an accessory duct. In addition, the RAHD can also be confused with the cystic duct and divided during cholecystectomy.
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In cases of laparoscopic bile duct injuries, what factor is associated with the best long-term peritontis?
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Immediate identification with immediate repair is associated with the best long term results. Unfortunately, in one recent study, only 10% of dutal injuries were discovered and operated on in the first week. The vast majority (70%) were diagnosed within the first 6 months.
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What is the best initial approach to take in patients with bile duct injuries and biliary peritonitis?
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It's usually caused by infected bile. Percutaneous drainage is the best initial strategy. Definitive repair of the lesion can be done when the infection is treated.
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What conditions make endoscopic removal of common bile duct stones difficult or impossible?
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Anatomical considerations such as previous uppre gastrointestinal surgery or a large sized calculus reduce the success of endoscopic extraction by most endoscopists.
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T/F: Management of an elderly frail patient with ductal calculi and severe gallstone pancreatitis differs from a young healthy patient.
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False. ERCP and sphincterotomy can be safely performed in the elderly. However following sphincterotomy and successful stone extraction some reports suggest that frail elderly patients can be successfully managed without a cholecystectomy.
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In a patient with recurrent bile duct stricture in whom a repeat attempt at operative bypass has failed or seems unwise, what option is available?
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Consideration may be given to balloon dilation or possibly placement of metal stent across the stricture.
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How long should a stent remain in place in a patient with a biliary fistula and concimitant stricture?
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They require long term stenting, preferably with large bore stents (10- or 11.5-French stents). These patients will need one or two 10-Fr stents placed with interval changes every 3 months for a mean of 10 months.
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If a patient has an external biliary fistula, what test should be done first?
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Fistulogram
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In what situation is the best result achieved when stenting a biliary structure?
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If the stenotic segment is short (less than 1 cm) or if the stenosis is partial.
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What is the usual closure time of biliary leaks in the absence of stricture?
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The majority of biliary leaks (not associated with stricture) close w/in 7 to 10 days after ablation of the biliary sphincter or stent placement.
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What are advantages and disadvantages of nasobiliary drainage?
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Adv. include the ability to repeat cholangiography and to remove it without the need of a second ERCP. The risk of infection when improperly cared for, poor patient acceptance and discomfort and potential for electrolyte disturbances from external drainage of bile have been cited as disadvantages of this approach.
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Name 3 possible mechanisms of benign obstruction at the level of the ampulla?
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Inflammation, fibrosis, or muscular hypertonicity.
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T/F: Biliary obstruction due to duodenal diverticula is a common occurrence.
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False. One should be wary of attributing biliary obstruction to a duodenal diverticulum. It is much more likely that the diverticulum is innocent and that the jaundice is due to a more usual cause, particularly gallstones.
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Name 2 reasons that the common duct is rarely injured by penetrating duodenal ulcers.
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1) the pancrease, which intervenes between most of the lower common duct and the duodenum, acts as a protective barrier and 2) most duodenal ulcers occur w/in 2-3 cm of the p ylorus, whereas the common duct meets the duodenum beyond this vulnerable area.
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Name the most common benign polyp arising from the mucosa in the preriampullary region.
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Mucosal polyp or papillary (villous) adenoma. The tumor is often multilobular or even multicentric and it may be difficult to distinguish from a low-grade carcinoma, even on frozen section examination.
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Name 5 causes of secondary sclerosing cholangitis.
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Operative trauma and ischemia, chronic choledocholithiasis, cholangiocarcinoma, chronic pancreatitis, and toxins such as absolute alcohol and fomaldehyde.
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Besides inflammatory bowel disease, name five chronic systemic diseases associated with sclerosing cholangitis.
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Recurrent pancreatitis, diabetes mellitus, celiac disease, rheumatoid arthritis and sarcoidosis.
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Name two conditions that can mimic primary sclerosing cholangitis.
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Extrahepatic portal venous obstruction and metastatic cancer of the liver.
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T/F: Surgery is indicated for patients with chronic pancreatitis and associated biliary strictures which produce chronic cholestasis.
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True. pg 41
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Describe 2 possible causes of obstructive jaundice in a patient with annular pancreas.
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1) recurrent pancreatitis in the head of the gland, causing edema or fibrosis that constricts the bile duct w/in the pancreas and 2) fibrosis of the duodenal wall, through which the terminal portion of the bile duct passes.
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How frequently do patients with hepatic artery aneurysms present with jaundice?
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Hepatic artery aneurysms, which are situated close to the bile ducts, present with jaundice in 50% of cases.
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Jaundice occurs in what % of patients with acute cholecystitis w/o evidence of cystic duct or common bile duct obstruction?
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15%. This may be due to inflammation and swelling of the cystic duct.
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What is the average time for choledocholithiasis to result in secondary biliary cirrhosis?
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5 yrs.
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What is the appropriate treatment for patients with polycystic liver disease who have cysts near the hilum of the liver causing compression of the bile ducts?
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Decompression of excision of the cysts and removal of any intraluminal debris.
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Acalculous cholecystitis accounts for what percentage of gallbladder perforation
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40%
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Name 2 anatomic variants leading to the development of common bile duct stones.
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Juxtapapillary diverticula and entry of the cystic duct to the distal CBD.
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List 3 outcomes of gallbladder perforation.
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Localized perforation is most common and leads to a pericholecystic abscess. Next, is free peritonitis followed by cholecystoduodenal or cholecystoenteric fistulae.
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What is the preferred treatment for lymphoma patients who present with obstructive jaundice?
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Chemotherapy is the preferred treatment. Local irradiation of the hilus of the liver may be used adjunctively.
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When is gallstone dissolution with ursodeoxycholic acid indicated?
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Ursodeoxycholic acid is a naturally occurring bile and is occasionally used for dissolution of radiolucent, non-calcific cholesterol gallstones. The stones must not exceed 2 cm in diameter.
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What is the recurrence rate of gallstones in patients treated with ursodeoxycholic acid?
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Recurrence is common - approx 50% recur within a 5-yr period. Patients should be monitored for gallstone recurrence by performing ultrasonography every 6 mo for the first yr. If all stones disappear, the treatment should be continued for 1 to 3 months. For recurrences, a second course may be effective.
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When is cholecystectomy indicated for patients who fail gallstone dissolution with ursodeoxycholic acid?
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It's recommended after the second failure.
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T/F: nonvisualization of the gallbladder on hepatic scintigraphy does not indicate pathology.
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False. Most often, nonvisualization of the gallbladder implies the existence of mechanical obstruction related to cholecystitis, cholelithiasis and less commonly, carcinoma of the gallbladder.
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Name the most common cause of ampullary obstruction.
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Stone or stones in the CBD.
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T/F: a pancreatogram may, on occasion, show obstruction of the bile duct and the pancreatic duct at the same level. This double duct sign is usually due to biliary tract stones.
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False. The double duct sign usually suggests invasive carcinoma.
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Name the 3 main indications for ERCP and sphincterotomy.
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1) postoperative residual stone in the CBD
2) complicated choledocholithatiasis 3) sphincter of Oddi dysfunction |
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Name the 4 most common sites of trauma to the extrahepatic bile ducts.
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1) common bile duct 58.3%
2) common hepatic duct 23.6% 3) right hepatic duct 5.5% 4) left hepatic duct 2.8% |
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Name the most common presentation and treatment approach for complete blowout rupture of the fundus of the gallbladder.
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Progressive early bile ascites requires early laparotomy while laparotomy can be delayed for an early seal of the perforation with delayed rupture.
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Name the most common presentation and treatment approach for avulsion of the gallbladder from the hepatic fossa.
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This usually results in hemoperitoneum requiring an early laparotomy.
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Name the most common presentation and treatment approach for contusion or incomplete blowout of the gallbladder.
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In general, minimal early symptoms occur. Late rupture of an ischemia-weakened fundus should be treated by laparotomy.
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T/F: Hemorrhoidal disease is more frequently associated with constipation than with diarrheal disorders.
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False. Studies suggest that diarrheal disorders are more frequently associated with hemorrhoidal disease.
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Procidentia refers to complete prolapse of the rectum. What are other forms of rectal prolapse?
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Procidentia involves visible protrusion of all the rectal layers through the anus. 2 other forms of rectral prolapse are mucosal prolapse in which only the distal rectal mucosa protrude through the anus and occult rectal prolapse which refers to internal intussusception of rectal tissue w/o visible protrusion through the anus.
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A 62-yr old female patient complains of a mass that intermittently protrudes through her anus. What is the differential diagnosis?
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Prolapsing internal hemorrhoids, anorectal varices, mucosal prolapse, rectal prolapse, anal/rectal polyps, anal/rectal tumors and hypertrophic anal papillae.
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T/F: Cirrhotic patients usually develop hemorroidal disease secondary to portal hypertension.
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False. Anorectal varices, not hemorrhoids, develop as a result of portal hypertension. They represent the communication between portal circulation through the superior hemorrhoidal veins and the systemic circulation through the middle and inferior hemorrhoidal veins.
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T/F: The classic endoscopic appearance of solitary rectal ulcer syndrome is a shallow, discrete 1-4 cm ulcer located at the posterior wall of the rectum 4-15 cm from the anal verge.
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False. Although the lesions in solitary rectal ulcer syndrome may be found on the posterior wall of the rectum, they are more commonly located on the anterior wall of the rectum.
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What are functionand morphological abnormalities that can be associated with solitary rectal ulcer syndrome?
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Solitary rectal ulcer syndrome is associated with some form of rectal prolapse or mucosal prolapse and thicker muscularis propria in the rectal wall. The condition is commonly associated with high anal sphincter pressure, failure of the puborectalis to relax during defecation and delayed rectal evacuation.
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What conditions predict a favorable response to biofeedback (pelvic floor retraining) therapy for fecal incontinence?
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The ability to contract the external sphincter during squeezing; some degree of rectal sensation, cooperative patient (ie no cognitive impairment, mental retardation, dementia or psychosis) and no evidence of complete denervation on electromyography.
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T/F: Anal and rectal carcinomas are more common in men.
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False. Rectal carcinoma is more common in men whereas anal canal tumors are nearly twice as common in women.
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T/F: Because of the anus' location at the very distal part of the gastrointestinal tract and its easy accessibility for digital examination, anal canal tumors produce smptoms early in the course of the disease and are usually diagnosed at an early stage.
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False. In about 60% of the patients with anal canal tumors, the tumor is discovered late. Indeed 15% to 30% are found to have metastatic spread at presentation. The symptoms are usually mild and nonspecific. Aprox 25% of patients with anal canal tumors are symptom free and the tumor is found incidentally during a routine examination.
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T/F: Adenocarcinoma is the most common malignant tumor of the anal canal.
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False. The most common tumor of the anal canal is squamous cell (70-80%). Adenocarcinoma is a rare tumor in the anal canal.
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What are two medical therapies for chronic anal fissure and which one of them has been shown to be more effective?
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Topical nitroglycerin and botulinum toxin injections. Both have been successfully used for the treatment of chronic anal fissure; however, the injection of botulinum toxin into the internal anal sphincter has been found to be more effective than topical application of 0.2% nitroglycerin ointment.
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What is the prevalence of fecal incontinence?
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The prevalence of fecal incontinence in the Western Hemisphere is 2% to 7% and increases with age. Surveys have shown prevalence rates of 18% in the older female population and 45% to 47% in nursing home residents and hospitalized elderly patients.
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What information can be obtained from anorectal manometry?
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Anorectal mamometry is helpful in measuring anal and rectal function. This includes measures of anal sphincter tone (at rest, during squeezing and during increase in intra-abdominal pressure), rectal sensation thrsholds, rectal compliance and the recto-anal inhibitory reflex.
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What information can be obtained from anal ultrasound?
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Anal ultrasound is helpful in assessing the integrity of the anal sphincters. Anal ultrasound is not helpful in the assessment of anal function.
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What is the pudendal nerve terminal motor latency (PNTML)?
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PNTML is the time interval between stimulation of the pudendal nerve and the electromyographic response associated with contraction of the external anal sphincter muscle. A prolonged nerve latency may suggest pudendal neuropathy. The sensitivity and specificity of this test for diagnosing pudendal nerve injury as a cause of fecal incontinence are disputed.
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What are the differences between the internal and external anal sphincters and their role in maintaining continence?
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The internal anal sphincter is composed of smooth muscle and is under the control of the enteric nervous system. Its main function is to maintain the resting tone of the anal sphincter. The external anal sphincter is composed of striated muscle innervated by the pudendal nerve (sacral branches S2 to S4) and is under voluntary control. The main role of the external anal sphincter is to contract voluntarily in response to a sudden increase in rectal or abdominal pressure so as to prevent inappropriate defecation.
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What is the relative contribution of the internal and external anal sphincter muscles to the resting anal tone?
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About 70% of the anal canal resting tone is derived from the internal anal sphincter and the remainder by the external anal sphincter muscle.
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A mamometric evaluation in a patient with fecal incontinence reveals a failure to increase anal sphincter pressure when asked to squeeze but a normal increase in pressure in response to coughing. Besides poor motivation or comprehension, what is the most probably explanation?
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An increase in external anal sphincter pressure in response to an abrupt increase in intra-abdominal pressure is triggered by receptors in the pelvic floor and mediated through a spinal reflex arc. Lesions of the cauda equina or sacral plexus will result in loss of both the reflext response and the voluntary squeeze. Higher spinal cord lesions will result in the findings described in the questions.
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What are typical findings on physical examination and anorectal manometry in patients with proctalgia fugax?
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Proctalgia fugax is one functional disorder of the anorectum. The diagnosis is based on symptoms alone. There are no specific findings on physical examination or anorectal manometry testing.
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A 40 yr old female complains of recurrent episodes of pain in the rectum that last for hours and are often brought on by sitting or lying down. Posterior traction of the puborectalis on rectal examination produces tenderness and pain. What is the diagnosis?
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The description is typical of levator ani syndrome. It is a functional disorder of the anorectum and its diagnosis is based on symptoms alone.
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T/F: Levator ani syndrome and proctalgia fugax frequently coexist.
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True. Although the 2 disorders can be distinguished on the basis of duration, frequency and quality of pain, they coexist more often than expected by chance.
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T/F: A multi-national working team (Rome Committee) recommends that the diagnosis of pelvic floor dyssnergia be based upon symptoms of difficult defecation in addition to manometric, electromyographic or radiologic evidence of failure of the pelvic floor to relax when attempting to defecate.
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True. pg 66
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T/F: The majority of patients with pelvic floor dyssynergia will benefit from biofeedback (pelvic floor retraining) treatment.
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True. Approx 2/3 of these patients can learn to relax the external anal sphincter and puborectalis muscles with biofeedback training and report associated decreases in both straining during defecation and the feeling of incomplete evacuation.
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T/F: Rectocele and mucosal intussusception can frequently be seen in healthy normal subjects.
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True. Rectocele, mucosal prolapse and rectal intussusceptions have been reported in normal asymptomatic subjects. Therefore, these finding should be interpreted with caution since they may not necessarily suggest a causal relationship with defecation disorders.
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T/F: Pelvic floor descent can be evaluated on physical examination.
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True. With the patient in the left lateral decubitus position, the level of the perineum relative to the ischial tuberosities is observed. The patient is asked to strain and the perineum should not descend beyond the outlet of the bony pelvis.
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T/F: Fecal impaction can be definitely excluded by digital examination.
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False. Digital examination can miss 30% of fecal impactions in the elderly because a large amount of feces can accumulate above the reach of the examining finger.
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What are indications for evacuation proctography (defecography) in the evaluation of anorectal and pelvic floor disorders?
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The AGA Medical Position Statement on anorectal testing techniques suggests the use of evacuation proctography in patients with constipation in whom pelvic floor dyssnergia, enterocele or anterior rectocele are suspected as the cause of impaired defecation. There is no support for the use of this technique for other purposes.
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What are the clinical findings of anorectal syphilis?
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Anal chancres in the skin around the anus, anal or rectal ulceration and rectal lesions resembling carcinoma have all been described. Enlarged and tender inguinal lymph nodes are often present. Serologic tests for syphilis should be performed prior to surgery for any atypical rectal lesion.
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T/F: Vesicles on the perianal region and within the anal canal are commonly seen in anorectal herpes infections.
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False. Although perianal vesicles are a characteristic finding in anorectal herpes infection, they are uncommon within the anal canal. Ulcerations of the anal canal are more commonly seen in anorectal herpes infection.
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T/F: The intersphincteric space is the most common anatomic location of anorectal abscesses.
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False. Perianal abscesses located just beneath the perianal skin are most common.
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T/F: In at least 1/2 of ulcerative anal lesions in HIV positive patients, no specific cause is found.
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True. Diagnostic considerations include syphilis, tuberculosis, Mycobacterium avium-intracellulare, herpes simplex, cytomegalovirus, fungi and neoplasm.
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T/F: Anogenital condylomata acuminata caused by human papillomavirus (HPV) is associated with adenocarcinoma of the anus.
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False. HPV (types 16 and 18) is associated with squamous cell carcinoma of the anus as well as the cervix and vulva. Condylomata acuminata and anal cancer may coexist; thus, it is advisable to obtain biopsies from suspected lesions and examine the anal canal before beginning treatment.
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What is anal sampling and how it is related to the continence mechanism?
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The anal canal is highly innervated and sensitive to pain, touch and temperature. This allows differentiation between gas, solids and liquids and allows for selective passage of rectal contents or voluntary contraction of the external anal sphincter to maintain continence. Loss of this anal sampling function may contribute to the development of fecal incontinence.
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T/F: The most common cause of primary anorectal abscess and anorectal fistula is Crohn's disease.
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False. The most common case of primary anorectal abscess and anorectal fistula is primary anal cryptoglandular infection.
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What is the most common type/location of anorectal fistula?
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Intersphincteric fistula.
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T/F: Endoanal ultrasound is the most useful test to diagnose an anorectal fistula.
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False. Magnetic resonance imaging is the most accurate modality for diagnosing and localizing the position of an anorectal abscess of fistula.
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T/F: A broad-spectrum antibiotic is the treatment of choice for an anorectal abscess.
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False. The primary treatment of an anorectal absceses is surgical. Except in patients with diabetes mellitus, leukemia and valvular heart disease, antibiotics are usually not required.
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T/F: Up to 30% of women will have an anal sphincter defect on endoanal ultrasonography after their first vaginal delivery.
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True. In addition, about 10% will complain of urgency or incontinence.
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What type of fistula is the most common embryologic developmental anomaly?
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Tracheoesophageal fistula (85-90%). Int he most common subtype, the upper part of th eesophagus ends as a blind sac while the lower part is connected posteriorly to the trachea.
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What is the H type fistula?
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When th eesophagus and the trachea are attached by a short connection, creating a H type fistula.
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What is the most common congential abnormality associated with esophageal atresia?
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Cardiac abnormality, most commonly patent ductus arteriosus and septal defects.
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When considering an operation for congenital tracheoesophageal fistula, what is the most important anatomic information the surgeons need?
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The type of fistual and whether the distance between the upper and lower ends of th eesophagus is long (long gap) or closely approximated (short gap).
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What is the most common anatomic presentation of esophageal duplication?
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In up to 80% of cases, it presents as a cyst w/o luminal connection.
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Where in the esophagus are duplication cysts most commonly encountered?
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The distal third (60%) followed by the proximal third (23%).
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At what age do vascular rings usually become symptomatic?
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Most commonly during infancy and early childhood; although they may present at any age.
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What are the most common vascular rings encountered in the pediatric population?
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Double aortic arches and right sided aortic arch with either patent ductus arteriosus or ligamentum arteriosum.
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With what lesion is dysphagia lusoria commonly associated?
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Aberrant right subclavian artery. The artery arises from the left side of the aortic arch and on its course to the right arm compresses the esophagus posteriorly.
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How common is an aberrant right subclavian artery in the general population?
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It has been estimated to occur in up to 1% of the population. The vast majority (90%) are asymptomatic.
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What are esophageal A-ring, B-ring, and C-ring?
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Radiographic terms. A-ring is usually asymptomatic and involves hypertrophied muscle typically 1.5-2cm above the squamocolumnar junction. The B-ring is synonomous with Schatzki's ring and involves only mucosa. A C-ring refers to the indentation on the esophagus created by the diaphragmatic crura.
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How common is a Schatzki's ring?
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Uknown, because most of Schatzki's rings are asymptomatic. They are found in up to 14% of routine esophageal barium studies.
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What is the relationship between luminal diameter of Schatzki's ring and dysphagia symptoms?
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Patients with Schatzki's ring and esophageal lumen less than 13mm will almost alwasy experience dysphagia, between 13-20 mm may or may not have dysphagia (~50%) and greater than 20mm will rarely have dysphagia.
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With what lesion is the "steakhouse syndrome" commonly associated?
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Acute dysphagia due to food impaction is commonly associated with a Schatzki's ring.
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What pathogenetic mechanisms have been implicated in the formation of Schatzki's ring?
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Pill-induced, gastroesophageal reflux desease and congenital.
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What is the best diagnostic test to detect an esophageal ring?
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Barium esophagram. Use of a barium tablet or mashmallow may help even further to identify the ring and to estimate its luminal diameter.
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How can a muscular ring be differentiated from Schatzki's ring radiographically?
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On barium swallow, the caliber of the muscular ring varies, and the stenosis may disappear with full distension. The Shatzki's ring does not vary in appearance.
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What is the usual histology of a Schatzki's ring?
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As the rings are most often located at the gastroesophageal junction, the upper face usually has squamous epithelium, and the lower face is covered with columnar cells.
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What are typical clinical signs of Schatzki's ring?
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Age greater than 40, intermittent and nonprogressive solid dysphagia, worse when eating is hurried.
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What percent of patients with Schatzki's ring remain symptom-free after dilation at 1, 2 and 3 years follow-up?
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68%, 35%, and 11% respectively.
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Where is the most common location of an esophageal web?
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Esophageal webs can appear anywhere in the esophagus but tend to occur most commonly in the proximal part.
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What % of patients with dysphagia will be found to have an esophageal web?
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5-15%
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What is the Plummer-Vinson or Paterson-Kelly syndrome?
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Esophageal web that is associated with glossitis, iron deficiency anemia annd koilonychia.
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What types of cancers have been associated with Plummer-Vinson syndrome?
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Pharyngeal and cervical esophageal cancers
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What dermatological diseases have been associated with esophageal webs?
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Cicatricial pemphigoid and epidermolysis bullosa. Other associated skin diseases include Stevens-Johnson syndrome, psoriasis and idiopathic eosinophilic gastroenteritis.
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After allogenic bone marrow transplantation, what complication has been associated with the development of an esophageal web?
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Graft-versus-host disease.
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T/F: Esophageal webs have a gender predilection.
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True. More common in women.
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T/F: Esophageal webs that are associated with iron deficiency improve with iron supplements.
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False. The webs do not seem to consistenly improve with iron therapy.
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What 3 esophageal disorders hve been associated with webs?
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Inlet patch, Zenker's diverticulum and esophageal duplication cyst.
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Which diverticulum is most commonly encountered in the esophagus?
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Zenker's diverticulum, that forms in the posterior midline between the inferior constrictor and the cricopharyngeus muscle (ie hypopharyngeal location)
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What is the estimated prevalence of Zenker's diverticulum in the general population?
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0.01% to 0.11%
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At what age does a Zenker's diverticulum commonly present
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Almost 1/2 of the cases will present during the seventh to eighth decade of life.
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How commonly does squamous cell carcinoma occur in a Zenker's diverticulum?
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Approx 0.4% of patients
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What surgical techniques are used to treat a Zenker's diverticulum?
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Diverticulopexy, diverticulectomy, and cricopharyngeal myotomy. Endoscropic approaches have been described.
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What is the most common cause of midesophageal diverticula?
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Esophageal motor dysfunction resulting in high intra-luminal pressure, outpouching and the formation of pulsion diverticula.
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What is traction diverticulum?
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Midesophageal diverticula were once considered to arise as a result of traction due to paraesophageal inflammation, most commonly from tuberculosis and fungal diseases.
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What is the likely cause of an epiphrenic diverticula?
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As with midesophageal diverticula, esophageal motor disorders are believed to be the underlying mechanism for epiphrenic diverticula.
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What is the clinical presentation of midesophageal diverticula?
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In most patients, the diverticula are asymptomatic and are incidentally discovered during barium esophagram. In a small number of patients, it can cause dysphagia and chest pain.
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What percent of dysphagia cases are due to esophageal diverticula?
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Less than 5%
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What 4 motility abnormalities have been documented in association with epiphrenic diverticula?
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Nutcracker esophagus, diffuse esophageal spasm, hypertensive lower esophageal
sphincter, achalasia and non-specific motility disorders. |
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What is "feline esophagus?"
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Transient transverse folds of the esophagus that can be observed on both upper endoscopy and double contrast barium esophagram. These folds are termed "feline esophagus" due to the resemblance to the cats esophagus.
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What are causes of "feline esophagus?"
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This appearance may be seen in asymptomatic patients as a normal variant and in patients with gastroesophageal reflux disease.
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What are the clinical characteristics of "ringed esophagus?"
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This rare cause of dysphagia is commonly observed in males and is due to multiple esophageal rings. It has been associated with GERD and asthma.
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What is esophageal intramural pseudodiverticulosis?
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Multiple, small (1mm-3mm), flask shaped outpouching of the esophagus.
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What is the pathogenesis of esophageal intramural pseudodiverticulosis?
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Cystic dilations of the esophageal gland ducts.
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What infection can be detected in about 1/3 of patients with esophageal intramural pseudodiverticulosis?
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Esophageal candidaiasis
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What esophageal lesion is almost always associated with esophageal intramural pseudodiverticulosis?
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Esophageal stricture located in the upper or mid-esophagus. The pseudodiverticula are often observed distal to the stricture.
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What is the incidence of an inlet patch?
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ranges between 4-10%
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What type of gastric mucosa can be found in an inlet patch?
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Gastric corpus or fundic mucosa that can include functional parietal and chief cells.
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What complications have been described in association with an inlet patch?
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Uncommonly, proximal esophageal stricture, ulcer and esophageal adenocarcinoma.
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What diagnosis should be considered in a newborn with nonbilious vomiting and an abdominal x-ray showing a distended stomach with an absence of air in the bowel?
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Gastric atresia. This condition most commonly affects the antrum and pylorus. The treatment is surgical.
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T/F: Congenital hypertrophic pyloric stenosis may first become manifest as an adult.
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True. However, most cases of adult hypertrophic pyloric stenosis probably occur secondary to chronic pyloric ulcer disease, severe gastritis or cancer.
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T/F: The therapy of adult and neonatal hypertrophic pyloric stenosis is the same.
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False. In neonates, the procedure of choice is a surgical pyloromyotomy. In adults, surgical resection of the pylorus is generally performed in order to rule out a small focus of cancer within the hypertrophied muscle.
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T/F: Gastric duplication occurs more commonly in women.
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True. Most become symptomatic in infancy.
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T/F: Gastric duplications are associated with gastric carcinoma.
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True. Surgical excision is the treatment of choice for gastric duplications.
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What are gastric diverticula most commonly located?
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Over 75% are located on the posterior wall w/in 2cm of the gastroesophageal junction.
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T/F: Most gastric diverticula are acquired and symptomatic.
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False. Most are thought to be congential and are asymptomatic.
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T/F: The histology of the remnant stomach in microgastria is normal
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True. This condition is usually associated with congenital cardiac abnormalities and most patients die within weeks to months of birth.
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What condition during pregnancy is associated with gastric atresia?
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Polyhydramnios
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What congential gastric tumor contains all three embryonic germ layers?
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Gastric teratoma. These tumors are rarely found in the stomach, occur almost exclusively in males and are usually found extragastrically, near the greater curvature of the stomach.
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T/F: Gastric teratomas are usually associated with other congenital abnormalities.
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False. The prognosis of these tumors is good. Surgical excision is the treatment of choice.
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What is the difference between true and false diverticula?
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False diverticula do not include the muscularis propria in the sac wall.
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T/F: Juxtapapillary diverticula have a strong association with gallstones.
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True. Also known as extralumincal duodenal diverticula or periampullary diverticula, they occur within 2 cm of the ampulla of vater.
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T/F: Intraluminal duodenal diverticula are lined by duodenal mucosa on the inside and outside of the structure.
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True. Also known as a windsock diverticula, this is a single saccular structure which originates in the second portion of the duodenum. They may be connected to the entire circumference of only part of the duodenal wall.
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Jejunal diverticula are associated with what disorders?
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They are typically seen in disorders of small intestinal motility such as progressive systemic sclerosis and visceral myopathies and neuropathies.
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A Meckel's divreticulum is the remnant of what embryological structure?
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The omphalomesenteric or vitelline duct.
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T/F: A Meckel's diverticulum occurs on the mesenteric border of the gut.
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False. It occurs on the antimesenteric border.
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T/F: The most common location for the Meckel's diverticulum is 10cm from the ileocecal valve.
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False. Most commonly they are 100cm from the ileocecal valve.
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T/F: The occurrence of and complications resulting from a Mecke's diverticulum is three times more likely in males than females.
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True.
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T/F: Heterotopic tissue is present in 1/2 of all Meckel's diverticula.
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True. The most common types are gastric mucosa, pancreatic tissue or a combination of the two.
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T/F: Detection of Meckel's diverticula by technetium-99m radionucleotide scanning is dependent on th epresence of gastric mucosa within the diverticula.
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True. Tecnetium-99m is taken up by the ectopic gastric mucosa and may be enhanced by blocking anion secretion from the mucosa with histamine type 2 receptor antagonists.
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What is the most common complication of a Meckel's diverticulum in children? In adults?
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Children - usually in infants and those younger than 5, gastrointestinal bleeding occurs most commonly. Adults - intestinal obstruction is more common.
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What is the frequency of complications resulting from a Meckel's diverticulum in the adult population?
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Approx 2%. They include obstruction, bleeding, diverticulitis, perforation and carcinoma.
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T/F: Intestinal duplications are hypothesized to develop from aberrant recanalization of the gut during morphogenesis and share the same blood supply with the native intestine.
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True.
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T/F: Duplication of the gastrointestinal tract are located on the mesenteric border of the gut.
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True.
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T/F: The most common segment of the gut for intestinal duplication is the colon.
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False. The ileum is the most common segment followed by the jejunum.
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T/F: Intestinal duplication may range from single cystic structures that do not communicate with the native bowel to tubular structures that share the lumen with the native bowel.
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True.
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T/F: Gastric mucosa may line intestinal duplications.
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True.
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T/F: Intestinal atresia and occlusion of the gut lumen is a common cause of intestinal obstruction in the neonate.
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True.
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Duodenal atresia and stenosis are frequently associated with what 5 congenital abnormalities?
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Esophageal atresia,
midgut malrotation, inperforate anus, annular pancrease Down's syndrome. |
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T/F: The distribution of gut atresia can range from the esophagus to the rectum.
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True.
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What is the incidence of small bowel atresia?
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1 in 3000 to 5000 lives births
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Describe the several types of intestinal atresia.
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Type 1- diaphragm of mucosa and submucosa obstructs the lumen but the bowel wall and mesentery are intact.
Type II - two blind bowel ends connected by a fibrous cord. Type III A - two blind bowel ends spearated by a mesenteric gap. Type III B - "apple peel" atresia - proximal small bowel atresia and absence of the distal superior mesenteric artery Type IV - "string of sausages" - multiple atretic regions throughout the small bowel |
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Duodenal atresia is thought to develop at what gestational age?
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Recanalization of the intestinal lumen from the solid cord stage occurs at 4-8 weeks of gestation.
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T/F: Polyhydraminos is frequently associated with gastrointestinal atresia of the distal gut.
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False. Proximal gut atresias are associated with polyhydraminos.
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A double-bubble sign on abdominal radiograph or ultrasound in a neonate is classic for what type of intestinal atresia?
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Duodenal atresia.
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T/F: Common presenting signs of a proximal )duodenal or proximal jejunum) atresia include...?
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Jaundice and bilious vomiting. Distal atresias often present with abdominal distension.
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What are the two major complications of guy malrotation?
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Volvulus around the vascular pedicle and duodenal obstruction secondary to Ladd bands.
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T/F: Ladd bands are peritoneal bands that pass from the cecum across the duodenum to the right upper quadrant or to the duodenum and form after malrotation of the gut.
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True
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Describe the gut anatomy following nonrotation.
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The small intestine (jejunum and ileum) lies on the right side of the abdomen and the colon is entirely on the left. The cecum lies in the left iliac fossa. The small bowel mesentery remains suspended by a narrow pedicle, leaving a high risk for volvulus.
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What is reversed rotation of the gut?
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The gut rotates clockwise instead of the normal 270 degrees counterclockwise rotation, resulting in the colon entering the abdominal cavity first. The colon then takes a position posterior to the superior mesenteric artery and the duodenum. The small bowel mesentery passes in front of the transverse colon.
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T/F: Less than 1/2 of midgut malrotations present in infancy.
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Falce. 50-80% present in infancy.
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T/F: Biliary atresia and congenital heart disease are associated with gut malrotation.
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True.
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T/F: Biliary atresia and congenital heart disease are associated with gut malrotation.
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True.
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T/F: Omphaloceles are sac-covered abdominal viscera herniating through the umbilical cord.
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Ture
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T/F: Gastroschisis is a small defect in the abdominal wall usually to the right of the closed umbilical ring through which there is massive evisceration of the intestines with direct exposure to amniotic fluid.
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Tue.
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What is the gestational age when gastroschisis or omphaloceles develop?
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Between the 5th and 10th week of gestation.
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What maternal serum level is associated with ventral fetal abdominal wall defecs such as omphalocele and gastroschisis?
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An elevated alpha-fetoprotein level.
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T/F: Volvulus of the small bowel in the absence of preexisting defects is more common in Africa, the Middle East, and India because of the ingestion of bulky foods after periods of fasting.
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True. Volvulus of the small bowel is rare in the US w/o preexisting defects.
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T/F: Intussusception is one of the most common causes of bowel obstruction in children under the age of 2.
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True.
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What is the cause and frequency of a pathologic lead point in pediatric intussusception?
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Most are idiopathic. Approx 8-12% will have a structural abnormality such as a polyp, leiomyoma or lymphoma. Benign lymphoid tissue has also been suggested as a potential lead point.
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What is the gestational age when gastroschisis or omphaloceles develop?
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Between the 5th and 10th week of gestation.
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What maternal serum level is associated with ventral fetal abdominal wall defecs such as omphalocele and gastroschisis?
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An elevated alpha-fetoprotein level.
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T/F: Volvulus of the small bowel in the absence of preexisting defects is more common in Africa, the Middle East, and India because of the ingestion of bulky foods after periods of fasting.
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True. Volvulus of the small bowel is rare in the US w/o preexisting defects.
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T/F: Intussusception is one of the most common causes of bowel obstruction in children under the age of 2.
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True.
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What is the cause and frequency of a pathologic lead point in pediatric intussusception?
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Most are idiopathic. Approx 8-12% will have a structural abnormality such as a polyp, leiomyoma or lymphoma. Benign lymphoid tissue has also been suggested as a potential lead point.
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T/F: Henoch-Schonlein purpura may lead to intussusception.
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True. The vasculitic bowel may result in an intramural hematoma that acts as a lead point for intussusception.
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T/F: Small bowel intussusception is a major cause of intestinal obstruction in adults in the Western world.
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False. Approx 5% of adult intestinal obstructions are caused by intussesceptions.
|
|
|
What is the frequency of a pathologic lead point in adult intussusception?
|
Approx 90% of adult intussusception will have an identifiable cause such as a polyp, tumor, Meckel's diverticulum and celiac disease with flaccid bowel.
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|
T/F: Reduction of an intussusception in a pediatric patient is first attempted by barium enema.
|
True. Barium enema is often successful in reducing an intussusception in a child.
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|
T/F: Reduction of an intussusception in an adult is first attempted by barium enema.
|
False. Since most adults have a lead point, surgery is indicated.
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|
|
What is the most common segment location for intussusception in pediatric population?
|
Ileocolic intussusception is the most common.
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T/F: In adults with intussusception, the proper surgical management, in the absence of infarcted or gangrenous bowel, is manual reduction.
|
False. Since many lead points in the adult population are malignant, manual reduction is not recommended. Instead, bowel resection of the affected segment is recommended.
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|
|
What clinical findings may be found in intestinal lymphangiectasia?
|
Steatosis, malabsorption, lymphocytopenia, hypogammaglobulinemia, protein-losing enteropathy, chylous ascites, chylous pleural effusion and peripheral edema.
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|
|
What 8 medical conditions may lead to secondary lymphangiectasia?
|
Abdominal/retroperitoneal carcinoma/lymphoma, retroperitoneal fibrosis, pancreatitis, tuberculosis, Crohn's disease, celiac disease, systemic lupus erythematosus and congestive heart failure.
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|
Congenital lymphangiectasia is also referred to as what?
|
Milroy's disease.
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T/F: Gastroschisis is a small defect that occurs at the junction of the umbilicus and normal skin.
|
True. It requires immediate operation because a membrane does not cover the bowel.
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|
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T/F: Long-term morbidity and mortality of gastroschisis are high because of necrotizing enterocolitis, bowel perforation or necrosis and prolonged total parenteral nutrition.
|
True.
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T/F: Omphaloceles are associated with extraintestinal birth defects whereas gastroschisis is rarely associated with other defects.
|
True.
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|
What % of Hirschsprung's disease involves the rectosigmoid colon?
|
75-80%
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|
A child presents with chronic constipation, abdominal distension, volvulus and perforation. What is the most likely diagnosis?
|
Hirschsprung's disease.
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T/F: Anorectal manometry typically reveals a normal sphincter profile and an abnormal rectoanal inhibitory reflex in Hirschsprung's disease.
|
True
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|
What cell type is absent in the submucosa and myenteric plexus of patients with Hirschsprung's disease?
|
Ganglion cells that migrate from the neural crest region.
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|
|
What pull through operations have been used to surgically treat Hirschsprung's disease?
|
Swenson technique, Duhamel procedure and Soave procedure.
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The colon and the rectum account for what % of all gastrointestinal duplications.
|
5% and 10% respectively
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T/F: Asymptomatic rectal duplication should undergo surgical resection because of the risk of neoplasia.
|
True.
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T/F: Malrotation of the colon occurs if the midgut fails to complete the 180 degree counterclockwise rotation as it return from herniation during the 10th to 12th week gestational period.
|
False. It is a 270 degree counterclockwise rotation.
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|
What associated anomalies have been reported in 30% to 60% of patients with malrotation?
|
Small bowel atresia, intussusception, Hirschsprung's disease and abdominal wall defects.
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An infant presents at one month of age with a proximal small bowel obstruction, volvulus or colonic ischemia. What is the most likely diagnosis?
|
Malrotation.
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T/F: Operative treatment of malrotation also includes an appendectomy because future diagnosis of appendicitis would be difficult.
|
True
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T/F: The midgut volvulus formed by malrotation is reduced by untwisting it in a clockwise rotation.
|
False. Reduction is performed in a counterclockwise rotation.
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T/F: Imperforate anus occurs in 1:1,000,000 live births.
|
False. It occurs in about 1:20,000 live births.
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T/F: Congenital abnormalities, such as genitourinary, cardiac and gastrointestinal anomalies are rarely associated with imperforate anus.
|
False. These anomalies occur in up to 50% of cases.
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|
What are three common chromosomal abnormalities associated with imperforate anus?
|
Down's syndrome, trisomy 8 mosaicism and fragile X syndrome.
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T/F: Infants with imperforate anus cannot pass meconium at birth
|
True. Some may have fistulae by which meconium can pass.
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T/F: Imperforate anus is classified as either a high or low lesion according to the relation of the rectum to the levator ani muscle.
|
True.
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T/F: For the complete evaluation of the patient with imperforate anus, an intravenous pyelogram and voiding cystourethrogram are recommended.
|
True
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|
Surgical treatment of high imperforate anus is successful what % of time?
|
70-80%
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|
|
What are the prerequisites for volvulus formation?
|
A dilated redundant colon and a narrow based mesocolon.
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|
|
Common symptoms of volvulus are abdominal pain, obstipation and abdominal distension.
|
True
|
|
|
What % of colonic obstructions in the US are caused by a volvulus?
|
Less than 10%.
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T/F: A volvulus occurs when a stool-filled segment of bowel twists about its mesentary.
|
False. A volvulus occurs when an air-filled segment forms a twist.
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T/F: The sigmoid colon is involved in 90% of all the volvuli seen in the U.S.
|
False. The number is closer to 60%.
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|
|
What segments (3) of the population are at risk for a volvulus?
|
The elderly, institutionalized and neuropsychiatric patients.
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What maneuver should be performed to reduce a volvulus in a patient with peritoneal signs?
|
Emergency exploratory laparotomy. W/o peritonitis, sigmoidoscopy or a barium enema may reduce the volvulus.
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|
What is the recurrence rate of a volvulus after non-operative reduction?
|
Greater than 40%
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T/F: Cecal volvulus generally occurs in younger patients.
|
True
|
|
|
What percentage of volvuli involve the cecum?
|
Less than 20%
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|
T/F: A cecal volvulus occurs because of an anomalous fixation of the right colon leading to a freely mobile cecum.
|
True
|
|
|
What % of volvuli involve the cecum?
|
Less than 20%
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|
|
T/F: A cecal volvulus occurs because of an anomalous fixation of the right colon leading to a freely mobile cecum.
|
True.
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|
|
What are 3 precipitating factors for a cecal volvulus?
|
Pregnancy, adhesions and an obstructing lesion of the left colon.
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|
|
What % of a cecal volvulus involves a full axial twisting of the associated mesentery and its blood vessels?
|
90%
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|
T/F: Colitis cystica profunda is characterized by the presence of submucosal mucus-filled cysts.
|
True
|
|
|
T/F: The rectum is rarely involved in colitis cystica profunda
|
False. Most lesions are found w/in 12cm of the anal verge.
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T/F: It is rare for patients with colitis cystica profunda to have rectal prolapse.
|
False. Rectal prolapse occurs 54% of the time.
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T/F: Pneumatosis cystoides intestinalis is characterized by multiple, thin-walled, non-communicating, gas-filled cysts with epithelial lining in the wall of the small or large intestines, or both.
|
False. The gas-filled cysts have no epithelial lining.
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T/F: Pneumatosis cystoides intestinalis is associated with chronic obstructive pulmonary disease, intestinal obstruction, collagen vascular disease (schleroderma) and iatrogenic conitions such as post-endoscopy or surgery.
|
True.
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|
T/F: Pneumatosis intestinalis is one cause of prolonged recurrent asymptomatic pneumoperitoneum
|
True
|
|
|
A plain radiograph of the abdomen shows linear, curvilinear, or cystic lucencies in the bowel wall. What is the diagnosis?
|
Pneumatosis intestinalis.
|
|
|
The amount of hydrogen in the cysts of pneumatosis intestinalis can approach 50% of the gas present.
|
True
|
|
|
What successful treatments have been reported for pneumatosis intestinalis?
|
High-flow oxygen breathing, hyperbaric oxygen, antibiotics and surgical resection.
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T/F: Surgical treatment has been shown to be curative in most cases of pneumatosis intestinalis.
|
False. Surgery is not always successful and more extensive pneumatosis may occur; therefore, surgery is indicated in fulminant cases such as those with a likelihood of bowel necrosis, sepsis and death.
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T/F: Malakoplakia is a rare chronic, granulomatous, inflammatory disorder that can affect the genitourinary and gastrointestinal tract.
|
True. It can also affect the skin, lung, bone and brain.
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|
|
What are the most common sites of the large bowel affected by malakoplakia?
|
Rectum, descending and sigmoid colon.
|
|
|
What are the peak ages of incidence of malakoplakia?
|
The age of incidence is bimodal with a small peak at 13 years of age and a late peak around the age of 57.
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|
Histologic examination of a colonic lesion shows von Hansemann's cells and Michaelis-Gutmann's bodies. What is the diagnosis?
|
Malakoplakia.
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|
|
Name 3 predisposing conditions associated with malakoplakia.
|
Chronic infection with Escherichia coli, sarcoidosis and tuberculosis.
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|
T/F: A defect in macrophage phagocytic or digestive activity has been proposed as a mechanism for the pathogenesis of malakoplakia.
|
True
|
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|
T/F: Congenital abnormalities of the gallbladder are frequently accompanied by congenital abnormalities of the extrahepatic biliary tree.
|
True. These ducts open separately into the duodenum.
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|
|
Define biliary atresia.
|
Obliteration of the intra- or extrahepatic bile ducts. There is some evidence to suggest that the ducts originally were present but were destroyed by an unknown process.
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|
|
What is the condition called when the liver parencyma contains just a few ducts?
|
Intrahepatic biliary hypoplasia. Hypoplasia of the intra- and extrahepatic bbiliary system is thought to represent an interval stage in the evolution of biliary atresia.
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|
T/F: The gallbladder is usually also involved in extrahepatic biliary atresia.
|
True. Usually, only a fibrous remnant remains.
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|
T/F: It is usually apparent at birth when biliary atresia is present.
|
False. It usually does not become evident until several weeks after birth.
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|
T/F: Choledochal cysts more commonly occur in men.
|
False. These cysts are about four times more common in women. There is also a higher incidence among Asians.
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|
|
Describe the three types of choledochal cysts.
|
Type 1 - fusiform dilation of the common bile duct.
Type 2 - diverticular outpouching of the common bile duct. Type 3 - small saccular dilation of the distal common bile duct. |
|
|
What type of choledochal cyst is more common?
|
1) Pancreatic reflux and 2) Distal common bile duct obstruction (presumably, failure of recanalization of the distal bile duct during intrauterine development leads to narrowing of the distal bile duct with proximal dilation).
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T/F: Type I choledochal cysts may be associated with intrahepatic bile duct dilation (Caroli's disease).
|
True
|
|
|
What are potential risks of choledochal cysts if left unattended?
|
Severe cholangitis and adenocarcinoma (about 10%). Surgical exision is the usual treatment of these cysts, which may become massive in size.
|
|
|
What is a Phrygian cap?
|
A congenital deformity of the gallbladder of no clinical significance whereby the fundus of the gallbladder is kinked.
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|
Air in the gallbladder in the setting of acute cholecystitis suggests the development of what clinical entity?
|
Cholecystoenteric fistula due to necrosis of the gallbladder wall.
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|
|
Name three congenital defects associated with intrahepatic biliary atresia.
|
Congenital rubella, trisomy 17 andn 18 and alpha-antitrypsin deficiency.
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|
What are the two main developmental abnormalities of morphology that account for most pancreatic congenital abnormalities?
|
Abnormalities of rotation and fusion.
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|
|
At about what week of gestation does the embryological development of the pancreas first appear?
|
About the 4th week of gestation, the pancreas first appears as two diverticula arising from the primitive foregut just distal to the stomach.
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|
What are the names given to the pancreatic ducts that arise from the ventral and dorsal pancreatic buds?
|
The ventral duct anastomoses with the dorsal duct to form the main pancreatic duct of Wirsung. The dorsal bud arises directly from the duodenal wall and undergoes varying degrees of atrophy to remain as the accessory duct of Santorini.
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|
|
What % of the population have normal ductal anatomy?
|
Approx 60-70%
|
|
|
What is the embryological cause of pancreas divisum?
|
Pancreas divisum results from incomplete fusion of the dorsal and ventral pancreatic ductal system.
|
|
|
What % of patients undergoing ERCP are found to have pancreas divisum?
|
It has been reported in up to 7-10% of patients undergoing ERCP. The prevalence may be even higher in patients undergoing ERCP for investigations of idiopathic pancreatitis.
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|
|
What is the clinical presentation of patients with symptomatic pancreas divisum?
|
Most patients with it are asymptomatic. Those patients that are symptomatic have symptoms suggestive of acute pancreatitis which is thought to occur secondary to a combination of the anomaly and stenosis of the minor duodenal papilla.
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|
|
At what age do patients with symptomatic pancreas divisum usually present?
|
The age of presentation varies widely but is most common between the third and fourth decades of life.
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|
|
What is the best means of diagnosing pancreas divisum?
|
ERCP with injection of the main and minor pancreatic ducts demonstrates incomplete fusion of the dorsal and ventral pancreatic ductal systems.
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|
|
What should be the initial therapeutic management of patients with symptomatic recurrect pancreatitis from pancreas divisum?
|
Therapeutic endoscopic sphincterotomy has been shown to decrease the frequency of recurrent attacks of pancreatitis in pancreas divisum.
|
|
|
What is a heterotopic pancreas?
|
A heterotopic pancreas also known as ectopic or aberrant pancreas is defined as the presence of pancreatic tissue that lacks anatomic and vascula continuity with the main body of the pancreas
|
|
|
Where are the most common locations for ectopic pancreatic tissue?
|
70% of the ectopic pancreatic tissue is found in the upper gastrointestinal tract, including the stomach, duodenal and jejunum. However, it has been seen in many other abdominal locations.
|
|
|
What is the most common presentation of patients with heterotopic pancreas?
|
Most cases of heterotopic pancreas are asymptomatic and the condition is generally discovered incidentally during the evaluation of other gastrointestinal disorders.
|
|
|
What is the endoscopic appearance of heterotopic pancreatic tissue?
|
Ecotopic pancrease appears as a well-defined dome-shaped defect with central umbilication.
|
|
|
What are the histologic findings on endoscopic biopsy of the nodule seen in heterotopic pancreas?
|
Endoscopic biopsy of the nodule yields only normal gastric mucosa because the pancreatic tissue is submucosal or subserosal in origin.
|
|
|
What should be the management of heterotopic pancreatic tissue when discovered?
|
Incidental lesions should be left alone since long term follow up has not established a relationship between ectopic tissue and symptoms in most patients.
|
|
|
What is an annular pancreas?
|
An annular pancreas is a flat band of pancreatic tissue completely encircling the second portion of the duodenum.
|
|
|
What is the clinical presentation of annular pancreas in the pediatric and adult population?
|
In the newborn, the lesion is associated with polyhydramnios and typically presents with inability to tolerate feedings. In adults, obstructive symptoms such as nausea and vomiting occur, particularly postprandially.
|
|
|
How is a diagnosis of annular pancreas established?
|
In neonates, a plain abdominal x-ray may reveal a classic "double-bubble" which is diagnostic of duodenal obstruction. In adults and older children, plain x-ray films are unhelpful and other studies such as ERCP are necessary to make the diagnosis.
|
|
|
What is the management of an annular pancreas?
|
In newborns and adults, the management is surgical bypass of the obstructing lesion.
|
|
|
What 3 conditions are associated with multiple congenital cysts of the pancreas?
|
Multiple congenital cysts are associated with polycystic disease, cystic fibrosis and Von Hippel-Lindau syndrome.
|
|
|
What is the management of congenital cyst of the pancreas?
|
Surgical resection or drainage may be required for some patients with symptomatic solitary cysts; however surgery is not usually necessary or advisable for patients with multiple cysts.
|
|
|
What congenital anomalies are associated with annular pancreas?
|
Duodenal atresia and Down's syndrome.
|
|
|
Where in the gastrointestinal tract is the most common site of foreign body impaction?
|
The esophagus is the most common site, especially at the level of the hypopharynx. Other common places are areas of physiologic narrowing and include the pylorus, restroperitoneal duodenum, ileocecal valve and the anus. The ileocecal region is the most frequent site of perforation beyond the esophagus.
|
|
|
Where in the esophagus are objects likely to become lodged?
|
Objects may become lodged at any of the areas of physiologic narrowing (cricopharyngeus, aortic arch, the left main stem bronchus, immediately above the esophagogastric junction) or any other area of structural abnormality (stricture).
|
|
|
Which adults are at an increased risk for swallowing foreign bodies?
|
Those who wear dentures, those who are mentally retarded, those with psychiatric illnesses and prisoners.
|
|
|
What is the most common symptom in patients presenting with an esophageal foreign body?
|
Dysphagia is the most common symptom followed by odynophagia, choking and drooling.
|
|
|
T/F: Most ingested foreign bodies that become lodged in the esophagus pass spontaneously.
|
True. 70% of ingested foreign bodies pass spontaneously and fewer than 1% result in perforation.
|
|
|
What is the most common physical finding in patients presenting with an ingested foreign body?
|
Usually the physical examination is normal; however, signs of crepitation should always be sought.
|
|
|
A chest x-ray reveals an ingested foreign body aligning itself in the ssagittal plane. Is the object more likely to be located in the esophagus or trachea?
|
Trachea. Tracheal foreign bodies align themselves sagittally and are best seen on lateral projections.
|
|
|
What is the best study for identifying a radiopaque foreign body in the esophagus?
|
Frontal view chest x-ray. Objects in the esophagus align themselves in the anteroposterior projections. Barium contrast studies are seldom helpful and should be avoided.
|
|
|
What is the best imaging study to identify a toothpick in the abdomen?
|
Plain x-rays are usually not helpful. Ultrasonograpy may identify a toothpick as a hyperechoic straight line or a bright hyperechoic dot with sharp posterior shadowing when viewed on end. Alternatively a CT scan may be helpful.
|
|
|
How are pointed objects best removed?
|
Pointed objects should be removed with the pointed end trailing in order to avoid mucosal injury. Under these circumstances, you should consider utilizing an overtube or a hood attached to the tip of the endoscope.
|
|
|
T/F: Enzyme preparations such as papain should be tried prior to endoscopy in all cases of meat impaction.
|
False. Besides being ineffective, it is important to avoid papain and other enzyme preparations because of the risk of perforation.
|
|
|
Prior to endoscopic removal of an ingested safety pin, what should be done by the endoscopist to increase the success rate?
|
Rehearsal of the retrieval process (dry run) should always be performed in order to facilitate removal of the object.
|
|
|
T/F: Blindly pushing a foreign body into the stomach followed by endoscopic retrieval is routinely advocated.
|
False. This technique should be avoided unless the lumen beyond the obstructing foreign body is adequately visualized and patent. In general, once the foreign body has passed into the stomach, it does not need to be retrieved as it will usually pass through the gastrointestinal tract without problem.
|
|
|
A 72-yr old woman is brought to the emergency room 72 hours after swallowing a pointed object. What is the best management at this point?
|
Endoscopic removal should be attempted in this patient if it can be localized and is retrievable. Indications for prompt removal of ingested foreign bodies include the presence of complete esophageal obstruction and ingestion of sharp, pointed or toxic objects (disc batteries) lodged in the esophagus.
|
|
|
T/F: A 23-year old man presents with fever, chills, neck pain and obvious subcutaneous emphysema two hours after accidentally swallowing a fish bone. Endoscopic removal by an experienced gastroenterologist is the most appropriate management for this patient.
|
False. This patient has evidence of possible esophageal perforation. Therefore, surgery is the treatment of choice.
|
|
|
What is the most appropriate management for a patient who is found to have ingested a foreign body that is embedded in the esophageal wall?
|
Surgery.
|
|
|
What are the most common symptoms of complete esophageal obstruction due to a foreign body?
|
Sialorrhea, regurgitation and choking.
|
|
|
T/F: Immediate endoscopic removal is the best approach for management of ingested latex packets of cocaine.
|
False. Endoscopic removal of such drug packets in unwise because of the potential for rupture upon manipulation.
|
|
|
What is the appropriate management of ingested elemental mercury in the intestine?
|
Observation and possibly cathartics to hasten its elimination as long as there is no evidence of perforation or leakage outside the digestive tract.
|
|
|
What is the best approach to take when an esophageal stricture is found once the foreign body has been removed or pushed into the stomach?
|
Dilatation of the stricture. If there is local mucosal trauma or bleeding or the patient is not cooperative or visualization of the field is suboptimal, the stricture is best dilated at a later time.
|
|
|
T/F: The location of the perceived discomfort is predictive of the most likely site of a foreign body lodged in the esophagus.
|
False. As with dysphagia in general, th elocation of the perceived discomfort does not usually correlate with the anatomic location of the obstructing foreign body.
|
|
|
What size objects should be considered for endoscopic removal?
|
Long objects greater than 6cm in children and greater than 10cm in adults should be removed. Rounded objects less than 2.5cm usually pass through the pylorus in adults and can be managed conservatively.
|
|
|
When should endoscopy be utilized in the mgmt of an ingested disc battery?
|
Endoscopy should be performed promptly if the disc battery is lodged in the esophagus. If it has passed into the stomach, conservative measures may be employed and the patient observed. If the battery has remained in the stomach for more than 48 hours, is greater than 1.5cm and has mercury, it should be promptly removed.
|
|
|
How long should you wait before contemplating endoscopic or surgical removal of a foreign body?
|
Asymptomatic blunt objects that fail to leave the stomach after 2 weeks should be removed endoscopically. Surgical removal of blunt objects beyond the stomach that fail to advance after 7 to 10 days (sharp objects > 3 days) should be considered. Surgical intervention is otherwise indicated if fever, vomiting, overt bleeding or abdominal pain develop.
|
|
|
Which patients are more likely to ingest caustic substances?
|
Children. It is estimated that 17,000 children, half of whom are under 4 years of age, accidentally ingest caustic substances each year. Although relatively uncommon in adults, it predominantly involves adults who are inebriated, mentally retarded, psychotic or suicidal.
|
|
|
What factors are implicated in the pathogenesis of caustic injury to the gut?
|
The nature, concentration and physical state of the agent, the amount ingested, the time of exposure ("dwell time") and the amount of reexposure secondary to vomiting or reflux are important factors.
|
|
|
How do alkaline agents cause injury?
|
Alkaline agents cause liquefaction (sponification) necrosis, which dissolves superficial mucosa and rapidly diffuse into deeper tissues. Blood vessel thrombosis causes further cellular necrosis potentially resulting in full thickness burns.
|
|
|
How do acidic agents cause injury?
|
Acidic agents produce a coagulation necrosis of the surface epithelium which tends to limit deeper penetration.
|
|
|
What region of the GI tract is more commonly affected by acidic agent ingestion?
|
Acidic agents usually cause extensive damage to the stomach. The esophagus is relatively spared due to a combination of factors which include rapid transit through the esophagus, greater resistance of esophageal squamous epithelium to acid and the protection afforded by superficial coagulation necrosis preventing deeper injury. Nevertheless, 20-50% of patients may have significant esophageal burns from ingestion of highly concentrated sulfuric or hydrochloric acid.
|
|
|
T/F: There is good correlation between oral/pharyngeal burns and esophageal or gastric injury.
|
False. The lack of oral of pharyngeal burns does not preclude the possibility of extensive esophageal or gastric injury.
|
|
|
T/F: Gastric lavage with water or administration of emetics play an important role in the management of caustic ingestions.
|
False. However if the patient is seen w/in the first hour of ingestion, gastric intubation, preferably under fluoroscopic guidance, with water lavage may be carried out. Emetics should always be avoided.
|
|
|
When should endoscopic examination be carried out in patients with suspected caustic ingestion?
|
Although controversial, most experts now agree on the need to document extent of damage with early endoscopy within 12 to 24 hours.
|
|
|
T/F: Endoscopic findings accurately predict the depth of tissue injury.
|
False. Grades of injury on endoscopy are not as precise as the pathologic degree of burn.
|
|
|
What are the 'Grades' of injury caustic by ingestion?
|
1st degree injury is characterized by mild friability, erythema and edema only. 2nd degree extends into the wall, occasionally to the muscularis propria. Ulceration, necrosis and exudate may be seen. 3rd degree involves the full thickness of the wall. A dark exudate with sloughing of the mucosa, hemorrhage, ulceration and necrosis are typically seen.
|
|
|
What is the role of antibiotics and corticosteroids in the mgmt of caustic ingestions?
|
The lack of controlled trials precludes definitive arguments in support of any therapeutic modality. The use of antibiotics and corticosteroids is fraught with controversy in the literature. However, corticosteroids may be considered if symptoms of laryngeal edema are present. Antibiotics are recommended in proven or suspected infection and in patients with 2nd degree and 3rd degree injury.
|
|
|
T/F: Administration of acid neutralizers is helpful immediately after caustic ingestion.
|
False. The heat produced in the neutralization reaction may actually increase tissue injury. Additionally, since most alkali injuries occur very rapidly, acid neutralization is ineffective.
|
|
|
When do strictures usually develop following caustic ingestion?
|
Most strictures (80%) present w/in the first 8 wks after injury. However, they can occur insidiously over months to years after the initial event.
|
|
|
What are long-term complications of caustic ingestion?
|
Recurrent or delayed strictures which occur in 15-38% of caustic exposures, especially in patients with more severe grades of injury, and the development of squamous cell carcinoma of the esophagus.
|
|
|
What is the usual latency period before squamous cell carcinoma develops?
|
It varies from 12 to 41 years and is shorter for injuries occurring after childhood. Specific surveillance protocols have not yet been defined.
|
|
|
What are the usual sites of stricture development in the esophagus and stomach?
|
Strictures tend to develop at sites of pooling such as the cricopharyngeus, aortic arch, bifurcation of the trachea and lower esophageal sphincter in the esophagus and the antrum of fasting patients and the mid-body in patients who have food present at the time of caustic ingestion.
|
|
|
What is the most sensitive imaging study to detect a suspected early perforation following caustic ingestion?
|
CT scan of the chest/abdomen with oral contrast.
|
|
|
T/F: Patients with gastroesophageal reflux disease (GERD) usually seek medical attention.
|
False. While an extremely common problem, the majority do not seek medical attention. A recent survey of 2000 randomly selected subjects in Minnesota revealed the prevalence of GERD to be 58 per 100 individuals. In dramatic contrast, only 5% of individuals had sought medical attention.
|
|
|
How often is endoscopic evidence of erosive esophagitis and Barrett's esophagus seen in patients with symptoms suggestive of GERD?
|
Up to 1/2 of patients with reflux sumptoms will have erosive esophagitis, albeit usuallly mild, and 11% to 12% will have Barrett's esophagus.
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|
|
What are the major physiologic mechanisms that protect against esophageal acid injury?
|
Esophageal clearance mechanisms (peristalsis/saliva), esophageal mucosal/epithelial integrity, antireflux barrier (lower esophageal sphincter) competence and gastric emptying are the four major physiologic mechanisms.
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|
What are the 3 mechanisms of lower esophageal sphincter (LES) incompetence and how often is each primarily responsible for GERD?
|
Transient LES relaxation - 65%
Increased intraabdominal pressure - 17% Spontaneous free reflux - 18% |
|
|
What factors are associated with severe esophagitis?
|
Low LES pressure, esophageal motor abnormalities and recumbent reflux are the most important determinants of severe endoscopic esphagitis. The presence of a hiatal hernia is also important.
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|
What esophageal histologic abnormalities are typical of GERD?
|
The basal zone occupying more than 15% of the total thickness of the epithelium and the papillae extending more than 2/3 of the distance to the surface. Esinophils and neutrophils are also commonly present. Unfortunately, the sensitivity and specificity of these findings, either individually or in combination, is only fair at best.
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What role does the hiatal hernia play in the pathogenesis of GERD?
|
This has been a controversial issue for the past 2 decades. Initially thought to be the only mechanism by which reflux occurred, later it was considered to be unimportant. However, recently it has been shown that the right crus of the diaphragm contributes significantly to the anti-reflux barrier, thereby stressing the importance of a normally placed gastroesophageal junction. Some studies have shown that the hernia sac acts as a reservoir for gastric contents (acid trap) and is associated with complicated forms of GERD such as severe esophagitis and peptic strictures, suggesting that it is a major contributory factor.
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T/F: There is a clear correlation between abnormal esophageal acid exposure of ambulatory pH monitoring, clinical symptoms and severity of esphagitis.
|
False. It appears that all 3 are independent although related aspects of GERD.No clear relationship exists between them.
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|
|
What is the cancer risk in Barrett's esophagus?
|
Esophageal adenocarcinoma whose incidence has been rising dramatically over the past 2 decades. A recent meta-analysis suggests that patients develop esophageal adenocarcinoma at a rate of approx 0.5% per year (annual incidence rate). These patients have a 30 to 125 times increased risk of developing esophageal cancer compared to the general population.
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What major clinical features help predict which patients who present with gastrointestinal bleeding can be managed w/o admission to the hospital?
|
Absence of hypotension, melena or hematemesis and age less than 60 years.
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Approx what % of patients wiith esophageal varices that have never bled will experience a variceal hemorrhage in the 1 to 2 years following their diagnosis?
|
Approx 1/3
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|
What endoscopic features of esophageal varices predict a high probability of hemorrhage?
|
Large size and red wale markings.
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|
|
What is the hepatic wedge pressure gradient below which bleeding from esophageal varices rarely occurs?
|
12 mmHg.
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|
T/F: An arteriovenous malformation (angiodysplasia) in a patient who has no evidence of GI blood loss should be cauterized to prevent bleeding.
|
False. The vast majority of angiodysplasia discovered at endoscopy are incidental findings and require no treatment.
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|
If one considers all the diagnoses found in a large number of patients who present with upper GI hemorrhage, what % have some form of acid-peptic disease?
|
85%
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|
The national mortality rate from GI bleeding has remained stable since 1945 and is approximately?
|
10%
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|
T/F: Oral iron therapy produces a false positive fecal occult blood test.
|
False. It may, cause visual interpretation errors.
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|
What is the average amount of blood/day lost in the stool of healthy individuals on no medications as determined by the chromate-tagged red cell test?
|
0.5 to 1.5 mL/day
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|
In experimental animals (and presumably in humans), at what rate must blood be lost into the gut lamen before arteriography is capable of demonstrating a bleeding site?
|
0.5 to 1.5 mL/min. The corresponding rate for a nuclear medicine red blood cell scan is 0.1 to 0.4 mL/min
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|
Approximately what % of patients with a GI hemorrhage will have no identifiable source despite careful evaluation including small bowel enteroscopy?
|
10%
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|
T/F: Intense inhibition of acid secretion slows or stops acute upper GI bleeding
|
False
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|
T/F: Intense inhibition of acid secretion prevents early rebleeding from peptic ulcer disease.
|
True
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|
|
What % of acute hemorrhages due to Mallory-Weiss tears stop spontaneously?
|
80%-90%
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|
Considering all causes of upper gastrointestinal hemorrhage except variceal, what is the rebleeding rate (with or w/o endoscopy)?
|
20%
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|
What is the advantage, if any, of esophageal variceal band ligation compared to sclerotherapy?
|
Fewer complications with banding
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|
|
What is the presently accepted efficacy rate (of stopping hemorrhage) for sclerotherapy or banding of esophageal varices?
|
85% to 90%
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|
|
What is the therapeutic efficacy (range) of a Sengstaken-Blakemore tube in controlling bleeding from esophageal varices?
|
Aspiration pneumonia and perforation of the esophagus by erroneously inflating the gastric balloon in the esophagus.
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|
What is the primary indication for angiographic infusion of vasopressors or embolization in the treatment of bleeding peptic ulcer disease?
|
Failure of therapeutic endoscopy to control bleeding or rebleeding not controlled by a second therapeutic endoscopy in a patient who is of poor operative risk.
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|
T/F: It is accepted as true that cure of Helicobacter pylori infection in a patient with a bleeding ulcer will prevent future bleeding episodes
|
.True - although not in everyone. The nonsteroidal anti-inflammatory drug status of the patient and location of the ulcer (i.e., gastric or duodenal) may play a role in those cases of recurrent ulcer bleeding.
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|
T/F: It is the national standard of care that a repeat endoscopy be done in order to prove healing of a duodenal ulcer that has bled.
|
False
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|
Given a patient with a third episode of bleeding from proven duodenal ulcer disease in the second portion of the duodenum, what diagnosis must be considered?
|
Zollinger-Ellison Syndrome (gastrinoma)
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|
What is the single most common risk factor for ulcer formation in patients who use nonsteroidal anti-inflammatory drugs regularly?
|
Age greater than 65 or 70 years.
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Upper GI hemorrhage is a documented problem in truly stressful and prolonged illnesses and after extensie surgery, especially neurosurgery and cardiac procedures. What, if anything, can be done to reduce the frequency of such bleeding episodes?
|
Intravenous or oral acid suppression. Sucralfate may also be useful in this setting.
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|
A so-called "herald bleeding episode" in which significant bleeding that spontaneously ceases occurs, is characterstic of what post-surgical situation?
|
An aorto-enteric fistual
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|
In a previously healthy, asymptomatic patient over the age of 40 years who presents with the sudden onset of severe lower abdominal cramping, an urge to defecate, passage of a fairly normal stool followed shortly by passage of gross blood, what should be your diagnosis of highest probability?
|
Ischemic colitis
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|
|
What is the eventual outcome of ischemic colitis in the vast majority of patients?
|
Spontaneous cessation of bleeding, usually w/o requiring blood transfusion and with no complications. Acute perforation (w/in 3 days) and late stricture formation are uncommon.
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|
In a previously healthy, asymptomatic patient over the age of 60 years who presents with the sudden passage of gross blood with little or no abdominal discomfort, what should be your diagnosis of highest probability?
|
Diverticular bleeding from the colon
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|
|
What is the most common cause of significant upper GI bleeding in patients of child-bearing age?
|
Duodenal ulcer disease
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|
|
If a patient with bleeding esophageal varices continues to bleed following two attempts at variceal banding or sclerotherapy, what is the recommended next therapeutic maneuver?
|
Emergency portosystemic shunt, usually by surgery or by transjugular intrahepatic portosystemic shunt (TIPS), depending upon the cause of portal hypertension, severity of th eliver disease and availability. A Sengstaken-Blakemore tube may be necessary in the interim.
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|
In a patient with massive upper gastrointestinal bleeding who is found to have isolated gastric varices, what is your diagnosis of highest probability?
|
Splenic vein thrombosis.
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|
|
In a patient who is vigorously bleeding from esophageal varices despite pharmocotherapy and banding of varices and who is waiting for a surgical suite to become available for portosystemic shunt, what therapeutic maneuver is available that may control the hemorrhage?
|
Sengstaken-Blakemore tube for tamponade.
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|
|
What is the most common complication of upper gastrointestinal endoscopy in a patient with active upper gastrointestinal hemorrhage?
|
Aspiration pneumonia.
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|
|
In a patient over 50 years old who presents with intermittent hematochezia without iron deficiency anemia, persistently normal colored stools, and a clear history of blood on toilet tissue, what is the approximate frequency of significant lesions that will be discovered on colonoscopy compared to sigmoidoscopy?
|
Less than 3%
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|
|
In an acutely bleeding patient, what is the first step in management?
|
Support the intravascular volume (ie fluid resuscitation). Once hemodynamically stable, further evaluation can safely be performed.
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|
|
T/F: Melena can only occur as a result of upper GI hemorrhage.
|
False. It may also occur due to a colonic lesion with slow transit resulting from partial obstruction.
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|
|
A 26-year old man presents with hematemesis, fever and severe pleuritic left chest pain a few hours after a severe vomiting episode. What is the most likely diagnosis?
|
Boerhaave's syndrome.
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|
A 56-year old man with chronic heartburn for many years presents with dysphagia and iron deficiency anemia. What is the most likely diagnosis?
|
Esophageal adenocarcinoma arising within Barrett's epithelium.
|
|
|
T/F: The incidence of recurrent ulcer hemorrhage is markedly reduced if Helicobacter pylori is eradicated.
|
True.
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|
|
T/F: A clean ulcer base has a very low incidence of rebleeding and requires no endoscopic therapy.
|
True. The incidence of rebleeding is less than 5%.
|
|
|
What are some clinical predictors of ulcer rebleeding?
|
Shock (hemodynamic instability), anemia, hematemesis and persistent bloody lavage.
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|
|
What information can be gleaned from a bloody nasogastric aspirate associated with hematochezia?
|
The patient is bleeding rapidly from the stomach or duodenum and has an increased risk of morbidity and mortality.
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|
|
T/F: A negative nasogastric aspirate implies that a patient could not have bled from the stomach or duodenum
|
False. It is possible that a gastric or duodenal ulcer may not have bled for some time and there is no longer blood in the stomach.
|
|
|
T/F: Older patients have increased morbidity and mortality related to ulcer hemorrhage.
|
True. This is due to the presence of comorbidities.
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|
|
What effect do comorbid illnesses have on survival from ulcer hemorrhage and the risk of rebleeding after endoscopic therapy?
|
Comorbid illnesses increase the risk of death from ulcer hemorrhage. They also increase the risk of rebleeding.
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|
|
Which ulcer sites are at higher risk for rebleeding?
|
Ulcers located high on the lesser curvature and posteriorly in the duodenal bulb are at higher risk due to their proximity to large arteries (left gastric, pancreatico-duodenal).
|
|
|
What is the range in size of a visible vessel?
|
A visible vessel ranges in size from 0.3mm to 1.8mm
|
|
|
What size vessel can be coagulated by monopolar electrocautery?
|
Vessels up to 1mm in diameter
|
|
|
How is blood flow related to the size of the artery?
|
The blood flow is related to the fourth power of the radius of the vessel
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|
|
Describe how arteries bleed in ulcer hemorrhage.
|
There is fibrinoid necrosis of the vessel wall. The vessel bleeds from both sides and does not contract because it is not completely severed.
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|
|
T/F: Endoscopic therapy should be utilized whenever a nonbleeding visible vessel is found.
|
True. The high risk of rebleeding in this situation mandates endoscopic treatment.
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|
|
What technique is needed for coagulation of vessels larger than 1mm?
|
Coaptive coagulation is needed for vessels larger than 1mm and can be used for vessels up to 2mm.
|
|
|
What is the mortality related to upper GI hemorrhage?
|
About 10%
|
|
|
What specific causes of GI bleeding are associated with increased mortality?
|
Esophageal varices and gastric cancer
|
|
|
What is the overall rate of rebleeding for ulcers
|
About 15% to 20%
|
|
|
What is the rate of rebleeding after endoscopic treatment of an ulcer?
|
About 10% to 30%
|
|
|
What is a Dieulafoy lesion?
|
A 'caliber-persistent' arter that protrudes from the mucosa with little or no surrounding ulceration. This lesion is usually treated with combination therapy using injection plus thermal therapy. Endoscopic band ligation may also be effective.
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|
|
T/F: According to a consensus statement from the National Institutes of Health, heater probe, bipolar electrocautery, laser and injection therapy are about equal in the ability to control ulcer hemorrhage?
|
True, in experienced hands.
|
|
|
T/F: Bleeding from gastric cancer is difficult to control.
|
True. In general, bleeding from tumors of any type is difficult to manage nonsurgically.
|
|
|
A 70-yr old lady presents with hematemesis. At endoscopy, erythematous linear streaks are noted in the antrum giving a watermelon appearance. What is the most likely diagnosis and treatment of choice?
|
Gastric antral vascular ectasia (GAVE) which may be treated by either laser or other thermal coagulation.
|
|
|
A 42yr old man presents with melena. On examination, he is found to have pigmented spots on the buccal mucosa. What syndrome may he have?
|
Peutz-Jegher's syndrome
|
|
|
A 47-yr old woman presents with melena and is found to have nicreased lunulae (Terry's nails). What may be the cause of her bleeding?
|
Variceal hemorrhage due to chronic liver disease.
|
|
|
What methods are available for the prevention of a first esophageal variceal hemorrhage?
|
Therapy with non-selective beta blockers and long-acting nitrates has been shown to be effective. Prophylactic band ligation has also been shown to be effective, but only in a few small series, therefore it currently is not recommended.
|
|
|
What endoscopic findings indicate increased risk for variceal hemorrhage?
|
Size greater than or equal to 5 mm, red wale signs, hematocystic spots.
|
|
|
Describe why varices bleed.
|
As the varices become larger, the wall tension increases and the varix bursts. The red wale sign is due to the thinning of the vessel wall.
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|
|
When a patient presents with melena and telangiectatic lesions in the lips, oral cavity, nailbeds or skin, what diagnosis should be entertained?
|
Osler-Weber-Rendu syndrome.
|
|
|
What does angiodysplasia occur mainly in the right colon?
|
The increased wall tension of the right colon is due to the larger diameter. The veins become partially obstructed and over years become dilated and tortuous forming the angiodysplasia.
|
|
|
How common are angiodysplasia?
|
More than 25% of asymptomatic individuals over age 60 have been found to have angiodysplasias.
|
|
|
T/F: Angiodysplasia can present as occult intestinal bleeding.
|
True in about 5%
|
|
|
What is the most common site of diverticular hemorrhage?
|
The proximal half of the colon accounts for most diverticular hemorrhage documented angiographically.
|
|
|
T/F: If a patient has one of six fecal occult blood test windows positive, this is a significant finding requiring colonoscopy.
|
True
|
|
|
T/F: Colonic biopsy can differentiate ischemic colitis from Clostridium difficile colitis.
|
False.
|
|
|
A 31-yr old man presents with abdominal distention and hematemesis. Upper endoscopy reveals blood coming from beyod the 2nd portion of the duodenum. What is the most likely diagnosis?
|
A jejunal volvulus with partial obstruction and ischemic necrosis.
|
|
|
A 51-yr old man presents with fever, right upper quadrant pain and hematemesis. Endoscopy reveals blood in the second part of the duodenum w/o any lesion noted. What is one possible cause of this scenario?
|
Acute cholecystitis with a cystic artery aneurysm that has bled into the bile duct.
|
|
|
T/F: Varices may return after eradication.
|
True. By 2 years, there appears to be a return of varices in 40% of patients.
|
|
|
What is the role of push enteroscopy in the evaluation and management of occult gastrointestinal intestinal bleeding?
|
Enteroscopy may be useful after a negative colonoscopy and upper endoscopy. If a telangiectasia is found, it can be coagulated using thermal techniques.
|
|
|
A 23-yr old woman presents with right lower quadrant pain and hematochezia. Upper and lower GI endoscopy are negative. Would a nuclear medicine scan be useful at this point?
|
The patient could be bleeding from a Meckel's diverticulum which could be identified by such a scan.
|
|
|
T/F: Diverticular hemorrhage can be controlled be endoscopic means.
|
True. If the bleeding site can be identified, injection around the orifice of the diverticulum or the endoscopic placement of clips may be helpful.
|
|
|
What size visible vessels should not be treated using endoscopically-delivered thermal therapy?
|
According to animal models, vessels larger than 2mm are more difficult to coagulate by coaptive coagulation using a heater probe or bipolar probe. Combination therapy should be used for borderline vessels. Large vessels, particularly in dangerous places (high in the stomach, posteriorly in the duodenal bulb), should be referred for urgent surgical therapy.
|
|
|
Perifollicular hyperkeratosis, also referred to as phrynoderma ("toad skin"), is seen in what 3 nutritional deficiencies?
|
Vitamin A, linoleic acid and B complex vitamins.
|
|
|
What are the three D's of pellagra?
|
Dermatitis, diarrhea and dementia
|
|
|
A deficiency in what two nutrients is responsible for pellagra?
|
Niacin (most commonly) and tryptophan.
|
|
|
What, other 6 reasons other than decreased nutritional intake of tryptophan or niacin, may cause pellagra?
|
Alterations in tryptophan metabolism secondary to carcinoid, Hartnup's disease, use of isoniazid, 5-fluorouracil, 6-mercaptopurine or sulfapyridine.
|
|
|
Vitiligo has been associated with what two nutritional deficiencies?
|
Vitamin B12 and folic acid.
|
|
|
What disease/nutritional deficiency leads to perifollicular purpura?
|
Scurvy/vitamin deficiency. Other findings include poor wound healing, corkscrew hairs and gingival bleeding.
|
|
|
Plummer-Vinson syndrome is associated with what findings?
|
A post-cricoid web, koilonychia, angular stomatitis, sore tongue and iron deficiency.
|
|
|
What percent of patients with Plummer-Vinson Syndrome are at risk of developing a carcinoma?
|
Between 5% and 10% will develop carcinoma at the site of the post-cricoid web. Patients with coexisting celiac disease may be at an even greater risk.
|
|
|
What is the classical dermatoligic finding in patients with hemochromatosis?
|
Bronze pigmentation of the skin.
|
|
|
What autosomal recessive condition leads to a perioral, acral and genital eczematous eruption, alopecia, glossitis and diarrhea?
|
Acrodermatitis enteropathica
|
|
|
What 5 gastrointestinal conditions may lead to acquired zinc deficiency?
|
Chronic inflammatory bowel disease with diarrhea and/or malabsorption, steatorrhea, pancreatic in sufficiency, cirrhosis and surgically induced conditions.
|
|
|
What percent of prophyria cutanea tarda (PCT) patients have associated chronic hepatitis C?
|
71% to 91%
|
|
|
What 3 drugs can precipitate an attack of VP?
|
Barbiturates, dapsone and estogens
|
|
|
What does CREST stand for?
|
Calcinosis cutis, Raynaud's phenomenon, esophageal dysmotility, scelrodactyly and telangiectasias
|
|
|
Patients with Ehlers-Danlos SYndrome (EDS) at at high risk for what GI problems?
|
Patients with Type IV (arterial subtype) EDS are at risk for rupture of the large intestine and/or rupture of the mesenchymal arteries in the abdomen.
|
|
|
Yellowish papules in flexural skin and rectal mucosa giving a "plucked chicken" appearance, ocular angioid streaks, hypertension and GI hemorrhage are indicative of what disorder?
|
Hernias (inguinal, umbilical and obturator), diverticula of the GI and genitourinary tracts and chronic diarrhea.
|
|
|
What GI manifestations are seen in patients with Bloom Syndrome?
|
This disorder is most frequently seen among Ashkenazi Jews. Approx 20% of patients develop neoplasms (50% before age 20), most commonly lymphatic, nonlymphatic leukemia, lymphosarcoma, lymphoma and carcinoma of the oral cavity and digestive system. Patients are predisposed to multiple infections of the GI and respiratory tracts. Other findings include sun sensitivity, facial telangiectasia, short stature and immunodeficieny.
|
|
|
What 2 malignancies have been associated with Fanconi's anemia?
|
Nonlymphatic leukemia and hepatoma.
|
|
|
Dyskeratosia congenitis (Zinsser-Engman-Cole Syndrome) is an X-linked disease with multisystem abnormalities. What GI findings may be seen?
|
Mucosal leukoplakia, lingual hyperkeratosis, esophageal stenosis, squamous cell carcinoma of the mouth, anus and esophagus, and adenocarcinoma of the pancreas and stomach.
|
|
|
What is the differential diagnosis of bullous lesions and/or ulcers of the oral mucosa?
|
Pemphigus vulgaris, bullous pemphigoid, epidermolysis bullosa, dermatitis herpetiformis, cicatricial pemphigoid, thermal burn, linear IgA dermatosis, herpes simplex, physical injury, syphilis, coxsackievirus, herpes zoster, deep mycoses, aphthous ulcers, Behcet's syndrome, Reiter's syndrome, and erythema multiforme.
|
|
|
What conditions with dermatologic manifestations are associated with GI bleeding?
|
Hereditary hemorrhagic telangiectasia, blue rubber bleb nevus syndrome, Ehlers-Danlos syndrome, pseudoxanthoma elasticum, Kaposi's sarcoma (Human Herpes Virus 8), vasculitides (Henoch--Schoenlein disease and polyarteritis nodosa) and Dego's disease (malignant atrophic papulosis).
|
|
|
What 5 conditions are associated with both gastrointestinal polyps and dermatologic manifestations?
|
Gardner's syndrome presents with multiple epidermal inclusion cysts, lipomas, osteomas of the face, Peutz-Jegher's syndrome presents with freckling around the mouth and on the lips. Cronkhite-Canada syndrome presents with patchy alopecia and nail changes. Neurofibromatosis or Von Recklinghausen's Syndrome, Type I presents with axillary and inguinal freckling, cafe au lait spots and neurofibromas. Cowden's desease in an autosomal disorder associated with multiple tricholemmomas (resembling warts) around the mouth, nose and ears.
|
|
|
What cutaneous signs may herald GI malignancy?
|
1) Dermatomyositis in adults (controversial) - gastric and colonic carcinomas.
2) Acanthosis nigricans - adenocarcinoma of the stomach and bowel, but is predominantly associated with obesity, medications, and endocrinopathies. 3) Sister Mary Joseph nodules (umbilical metastases) - carcinoma of the stomach, colon and ovary. 4) Muir-Torre syndrome - autosomal dominant disorder presenting with multiple sebaceous tumors is associated with colon cancer. 5) The sign of Leser-Trelat (controversial) - sudden onset of multiple, pruritic seborrheic keratoses has been reported to occur with malignancy of the stomach, breast, prostate, lung and colon. 6) Acrokeratosis of Bazex - symmetrical psoriasisform eruption affecting the hands, feet, ears, nose is seen predominantly in males and is associated with tumors of the pharynx, esophagus, tongue and lungs. 7) Erythema gyratum repens - raised, erythematous, concentric eruption that moves on the skin and is likened to a "wood grain" pattern has been associated with tumors of the breast, lung, bladder, prostate, cervix, stomach, esophagus and multiple myeloma. 8) Ataxia telangiectasia - oculocutaneous telangiectasia, xerosis, gray hair, atrophic or sclerotic skin, recurrent impetigo with progressive cerebellar ataxia and an increased incidence of tumors of the oral cavity, breast, stomach and pancreas 9) Sweet's syndrome (acute febrile neutrophilic dermatosis) - presents as erythematous to bluish papules or nodules that coalesce to form well-demarcated plaques, likened to a "relief of a mountain range". 20% of cases are associated with malignancy. Most commonly seen with acute myelocytic leukemia, it has also been reported to occur with gastric carcinoma and adenocarcinoma of the rectum 10) Acquired ichthyosis - excessively dry skin with tessellated or tile-like scale predominantly on the lower extremities can be seen in many underlying gut tumors, but most commonly is associated with lymphoma |
|
|
From what cells do carcinoid tumors arise?
|
Enterochromaffin or Kulchitsky cells
|
|
|
In what sites do carcinoid tumors reside?
|
While the appendix is the most common site, the ileum, the second most common site, is more likely to be the origin of the classic carcinoid syndrome and is the most frequent site of the origin of metastases. Other sites for carcinoid tumors are the rectum, duodenum, stomach, colon, biliary tract and pancreas.
|
|
|
What differences occur in the carcinoid syndrome depending on where the tumor originates in relation to the embryologic foregut, midgut and hindgut?
|
The foregut tumors (bronchus, stomach, pancrease), in addition to serotonin, also produce histamine leading to peptic ulcer disease, brighter an dmore persistent flushing reactions, lacrimation, sweating, vomiting and asthma. Midgut tumors (small intestine to midcolon) are associated with a bluish flushing with mixed erythema and pallor, hypotension and bronchoconstriction. Hindgut tumors (descending colon and rectum) are not associated with flushing or other manifestations or carcinoid syndrome.
|
|
|
What conditions should be considered in a patient with a painful, erythematous nodule of the lower extremity and known inflammatory bowel disease?
|
1) Pyoderma gangrenosum begins as a painful nodule or pustules then develops into an ulcer with a serpiginous, erythematous to violaceous border and boggy, necrotic base and may not resolve once the bowel disease is under control.
2) Erythema nodosum lesions are erythematous, painful nodules predominantly on the extensor surfaces of the lower extremities and may precede the onset of inflammatory bowel disease. Both disorders are more common in patients with ulcerative colitis than Crohn's disease. Pyoderma gangrenosum has also been found in patients with chronic active hepatitis, diverticulitis, primary biliary cirrhosis, gastric and duodenal ulcers, rheumatoid arthritis, myeloma, and collagen-vascular diseases, Erythema nodosum has also been found in patients with sarcoidosis, bacterial, viral, AFB and fungal infections, Behcet's, oral contraceptive use and lymphoma. |
|
|
What haplotypes are most commonly associated with dermatitis herpetiformis?
|
HLA-B8, -DR3, -DQw2
|
|
|
What GI condition is associated with dermatitis herpetiformis?
|
Gluten-sensitive enteropathy.
|
|
|
What treatment options are available for dermatitis herpetiformis?
|
Dapsone, sulfapyridine (in dapsone intolerant patients) and a gluten free diet have all been offered as treatment options. A gluten free diet will resolve the intestinal and skin lesions; however, the skin lesions respond more rapidly to medication. It can take five months to a year for the diet to eliminate the need for medication in most, but not all, patients with this condition.
|
|
|
What diagnosis should be considered in a patient with periorofacial, intertriginous and perigential circinate lesions with vesicle, crusting and postinflammatory pigmentation in association with glossitis, weight loss, diarrhea and diabetes?
|
Glucagonoma. Arising in the islet cells of the pancrease, glucagonoma is associated with a distinctive dermatitis referred to as neocrolytic migratory erythema (NME). It is histologically similar to the lesions seen in acrodermatitis enteropathica and since the rash of NME may be an early sign in slow-growing tumors, this differential should be kept in mind.
|
|
|
What GI manifestations may be seen in patients with urticaria pigmentosa?
|
Gastric hypersecretion due to elevated plasma histamine leading to gastritis and peptic ulcer disease, diarrhea, abdominal pain, malabsorption in 30%, and abnormal liver tests, in particular alkaline phosphatase.
|
|
|
What skin changes may be seen in patients with Hep C?
|
Leukocytoclastic vasculitis, cryoglobulinemia, pruritis, porphyria cutanea tarda, erythema nodosum, urticaria, erythema multiforme, polyarteritis nodosa, lichen planus, jaundice and excoriations from itching.
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What skin changes may be seen in patients with Primary Biliary Cirrhosis?
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Melanosis, predominantly in exposed areas, clubbing, scleroderma-associated features, lichen planus, jaundice, exorciations from itching, xanthomas on the hands feet and trunk, xanthelasma and occasionally tuberous xanthomas.
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What skin changes may be seen in patients with Wilson's disease?
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Azure lunulae or bluish color of the lunular area of the nails and Kayser-Fleischer rings of the cornea.
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Where in the esophagus are you most likely to find heterotopic gastric mucosa?
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The cervical region is the most common location. This is also referred to as an inlet patch.
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What is the pathology of achalasia?
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It is characterized in part by nearly complete absence of the myenteric plexus w/in the esophagus.
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What infectious agent and disease present a nearly identical clinical and pathologic scenario as idiopathic achalasia?
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Infection with Trypanosoma cruzi causes Chagas' disease which results in findings similar to achalasia.
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In a patient with achalasia, what type of esophageal tumor occurs at an increased rate compared to control populations?
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Squamous cell carcinoma.
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What is the most common type of esophagitis in biopsy specimens and what are the histologic features?
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Reflux esophagitis is the most common type and is characterized by epithelial hyperplasia, elongation of the papillae, basal hyperplasia, spongiosis, vascular ectasia w/in the papillae and epithelial infiltration by neutrophils and eosinophils.
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In a biopsy of Barrett's esophagus, at what pH should one use an alcian blue stain to demonstrate the specific mucin seen in the specialized intestinal metaplastic cells?
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The alcian blue stain should be at an acidic pH of 2.5.
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How frequently would you expect to see specialized columnar epithelial metaplasia in a biopsy of reflux esophagitis?
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In about 10% of cases.
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List 8 risk factors for development of squamous cell carcinoma of the esophagus.
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Smoking, alcohol, history of lye stricture, achalasia, previous radiation, Plummer-Vinson's syndrome, diverticula and tylosis.
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T/F: In progressive systemic sclerosis (scleroderma), the esophagus is commonly involved.
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True. About 80% of patients have some esophageal abnormality.
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What is the typical age, race and gender of patients who develop squamous cell carcinoma of the esophagus?
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Greater than 50 years of age, African-American and male. It is interesting that whites have a higher incidence compared to blacks of adenocarcinoma arising in Barrett's esophagus.
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What are typical histological findings in the esophagus of a patients with progressive systemic sclerosis?
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Smooth muscle atrophy, fibrosis and hyaline thickening with luminal narrowing of small arterioles.
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What is the most common type of tissue heterotopia in the stomach?
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Pancreatic tissue is most common and is usually present in the submucosa of the distal stomach, antrum or pylorus.
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What organism is associated with development of lymphoma of gastric mucosa-associated lymphoid tissue (MALT)?
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Helicobacter pylori
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What stain(s) would you use to highlight H. pylori in a gastric biopsy tissue section?
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A number of stains can be used. Silver-based stains work very well but are more expensive. Inexpensive and easily performed stains commonly used are Giemsa and Diff-Quik.
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What three forms of hypertrophic gastropathy are characterized by enlarged rugal folds?
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Menetrier's disease, hypertrophic-hypersecretory gastropathy and gastric gland hyperplasia in Zollinger Ellison syndrome.
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Describe the usual histologic appearance of Menetrier's disease?
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Gastric glandular atrophy with pronounced hyperplasia of the overlying superficial mucos producing cells.
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What are the usual demographic characteristics and clinical presentation of the typical patient with Menetrier's disease?
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It is 3 times as common in men as women; typically ranges in age from the 4th to 6th decade of life; and, presents with weight loss, abdominal pain and occasionally peripheral edema.
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Where in the stomach would you be most likely to find an adenomatous gastric polyp?
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The antrum.
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T/F: Gastric polyps are frequently a component of familial adenomatous polypsis and Gardener's syndrome.
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True. Gastric polyps of some type (adenomatous, fundic gland, or hyperplastic/regenerative) are present in more than 1/2 of the patients. Most commonly, the polyps are of the fundic gland type.
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According to Lauren, what are the two general categories of gastric carcinoma?
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Intestinal type (50%) and diffuse type (33%) with combinations making up the remainder. The classic linitis plastica is the most characteristic type of diffuse gastric carcinoma and is characterized by an infiltrating signet ring cell carcinoma.
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Where are gastrinomas typically found in patients with Zollinger-Ellison syndrome?
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The majority are in the pancreas or duodenum.
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What are typical microscopic findings in the antrum in a patient with Menetrier's disease?
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Trick question! The antrum is typically spared and the transition to the other involved areas is abrupt.
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Describe the typical histologic features of so called chemical gastritis?
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The foveolae are hyperplastic with increased luminal serrations, the antral glands are atrophic, the lamina propria is fibrotic with splayed smooth muscle fiber and there are increased number of congested and somewhat ectatic superficial capillaries.
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How is autoimmune gastritis associated with pernicious anemia inherited?
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It is autosomal dominant with incomplete penetrance. It has a particularly high incidence in people of northern European descent.
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What tumor of the stomach is seen at an increased rate in patients with autoimmune gastritis?
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Carcinoid.
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What is the characteristic ultrastructural finding in carcinoid tumor cells?
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Dense core neurosecretory granules.
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What is the most common site of origin of primary lymphoma in the GI tract?
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The stomach in about 50% of the cases.
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What is the most common site of original of GI stromal tumors (GIST)?
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The stomach accounts for about half of all cases.
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A sphindle cell tumor in the wall of the stomach is found to be CD117 positive via immunohistochemistry. What is the most likely diagnosis?
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GI stromal tumor (GIST)
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What structure, if it persists, is the origin of persistent fibrosis cord (from umbilicus to the bowel wall), enteroumbilical fistula and Meckel's diverticulum?
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The vitelline or omphalomesenteric duct.
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What is the typical histology of a Meckel's diverticulum?
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This is a congential anomaly which results from persistence of the proximal vitelline duct; is found w/in 90 cm of the ileocecal valve on the antimesenteric border; and, is usually lined by small intestinal mucosa. However, gastric, duodenal, colonic or pancreatic mucosa may also be found.
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What is the rule of "two's" as it refers to Meckel's diverticulum?
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Meckel's diverticulum is found within two feet of the ileocecal valve, is two inches long, causes symptoms in 2% of cases, and is found in 2% of the population.
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T/F: Hirschsprung's disease is more common in males than females.
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True. Hirschsprung's disease is characterized by a loss of both the submucosal (Meissner's) and myenteric (Auerbach's) plexuses with resultant nerve trunk hyperplasia. The gender incidence varies - males are four times more likely to have a short segment of affected colon while patients with long segments are more frequently female. In addition, 10% of Hirschsprung's disease is found in patients with trisomy 21 (Down's syndrome).
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What is the main histologic finding in patients with gluten-sensitive enteropathy?
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Markedly blunted villi with an increased number of intraepithelial lymphocytes and plasma cells within the lamina propria.
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What antibodies may be present in patients with celiac sprue?
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Anti-gliadin, anti-endomysial and anti-reticulin. There may also be antibodies to tissue transglutaminase.
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What HLA type is found in 80% of patients with celiac sprue?
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HLA B8
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What would you expect to see histologically in the small bowel from a patient with disaccharidase deficiency?
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Normal small bowel mucosa.
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Where would you look in a small bowel biopsy for the causative agent of Whipple's disease?
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The Tropheryma whippelii organisms reside in macrophages which are "stuffed" with organisms amidst an expanded lamina propria. These organisms can be confused with mycobacterial organisms. An acid fast stain is useful to differentiate between the two.
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A 67-year old man on chronic hemodialysis presents for further evaluation of chronic diarrhea. A small bowel biopsy contains glassy eosinophilic material which stains positively with a Congo red stain. What is the diagnosis?
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GI amyloidosis. Thioflavin T or S would also stain the amyloid.
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What diagnostic methodology is necessary to diagnose microvillus inclusion disease on a biopsy?
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Electron microscopy. This autosomal recessive condition is characterized by absence of surface villi and, ultrastructurally, microvillus inclusions are found within the cytoplasm of the enterocytes. Unfortunately, death prior to the age of two is common unless small bowel transplantation occurs.
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What is the inheritance pattern of abetalipoproteinemia?
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Autosomal recessive.
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What condition of the large intestine typically occurs in premature infants, can be associated with umbilical artery catheterization and results in abdominal distention, loss of bowel sounds, bloody stools and the presence of pneumatosis intestinalis?
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Neonatal necrotizing enterocolitis.
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If you suspect a patient has an adenocarcinoma of the small bowel, where would you most commonly expect to find it?
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The duodenum is the most common site of primary adenocarcinoma of the small bowel.
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What specific race and disease might you expect to find in a patient with an endocrine tumor of the duodenum which is of the delta-cell type?
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African-American patients with von Recklinghausen's disease have an increased incidence of delta-cell type endocrine tumors of the duodenum. Delta cells produce somatostatin.
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A tumor is resected from the ileum and your friendly pathologist tells you that grossly the tumor is well circumscribed, nodular and has a distinctly yellow cut surface. What type of tumor do you suspect this is?
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This is the classic appearance of a carcinoid tumor.
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What autosomal dominant condition is found in people of Mennonite descent in Canada, is associated with diarrhea and dehydration in young children and can be deadly?
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Torkelson syndrome. These patients sometimes show evidence of common variable immunodeficiency. Histologically, the changes are nonspecific and include blunting of the villi, edema and focal acute inflammation.
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What is acrodermatitis enteropathica?
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This is an autosomal recessive condition that is found in children, usually responds to administration of zinc sulfate and shows ultrastructural rod-like fibrillar inclusions w/in Paneth cells.
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What pinworm would you expect to find either as an incidental finding in the appendix or, less commonly, associated with acute appendicitis?
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Enterobius vermicularis. This organism is found in about 3% of appendectomy specimens in the United States.
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A patient has an appendectomy for acute appendicitis. Histologic sections of the appendix show multinucleated giant cells which are called Warthin-Finkeldey cells. What viral illness do you suspect?
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Warthin-Finkeldey cells occur in the prodromal stage of measles infection in the appendix. The patient will likely develop a typical measles rash in the near future.
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What is a mucocele of the appendix?
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It is an etiologically nonspecific term that, unfortunately, engenders a great deal of confusion. It is probably best thought of simply as a descriptive term describing a dilated appendix filled with thick mucin. The causes include retention cysts, mucinous cystadenomas and mucinous cystadenocarcinoma.
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A patient has a peritoneum which is filled with mucinous material. Histologically, sections demonstrate bland-appearing glandular epithelium floating in the middle of the large pools of mucin. What is your diagnosis?
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Pseudomyxoma peritonei.
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What is the difference between acquired and congenital diverticula?
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Acquired diverticula either lack a muscularis propria or it is greatly attenuated while congenital diverticula, such as a Meckel's diverticulum, contain all three layers of the intestinal wall.
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What is the term given to describe the presence of numerous submucosal gas filled cysts which create polypoid projections in the mucosa of the bowel?
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Pneumatosis intestinalis. In children, it is associated with neocrotizing enterocolitis and in adults there is usually an associated gastrointestinal disorder or chronic obstructive pulmonary disease.
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How frequently is the ileum involved in Crohn's disease?
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About 3/4 of patients will have ileal involvement.
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What is the term given to describe the type of colitis that is characterized by thickening of the subepithelial collagen band?
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Collagenous colitis.
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What is the term given to describe the type of colitis that is characterized by thickening of the subepithelial collagen band?
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Collagenous colitis.
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What is the term given to describe the colitis characterized by increased numbers of intraepithelial lymphocytes that is characteristically seen in middle aged women with watery diarrhea?
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Lymphocytic or microscopic colitis.
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Who do ya luuuuuuv?
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meeeeeeeeeeeee!
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What is the normal, allowable number of lymphocytes per 100 epithelial cells in the surface epithelium of the colon?
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Five
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Discuss some of the microscopic features you would expect to see in a biopsy of solitary rectal ulcer syndrome (mucosal prolapse syndrome)?
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In spite of the name of "solitary", about one of ten cases are not solitary at all but rather are multiple. The crypts are dilated with irregular branching which can impart a villiform appearance. The goblet cells are often mucin depleted and the lamina propria exhibits fibrosis and vascular congestion.
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Behcet's syndrome in the colon is characterized by what histologic/endoscopic findings?
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It is characterized by ulcers occurring in various parts of th elarge intestine with an associated "lymphocytic vasculitis" of the submucosal veins. This can result in a colitis which may mimic Crohn's disease.
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What is the most common polyp in children?
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Juvenile or retention polyp; however, again in spite of the name "juvenile", more than 30% of cases are diagnosed in adults. The most common site of occurrence is in the rectum.
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T/F: Arteriovenous malformation in the large intestine are most commonly found in the rectum.
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False. The vast majority are in the cecum and ascending colon.
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What are some of the basic histologic features of an adenomatous polyp?
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Decreased mucin production, nuclear pseudostratification and hyperchromasia, basal nuclear debris and either a tubular, villous or tubolovillous architecture.
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Name 3 histologic features that help determine the presence of so-called pseudoinvasion of the stalk in an adenomatous polyp as opposed to true malignant invasion?
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1) The glands are surrounded by a loose lamina propria stroma not a desmoplastic tissue response.
2) There are associated hemosiderin-laden macrophages. 3) The glands in the stalk are identical to those that are more superficially located. |
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In what fashion is Peutz-Jeghers syndrome inherited?
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Autosomal dominant. It is characterized by multiple hamartomatous polyps of the gastrointestinal tract and abnormal pigmentation of mucosa and skin.
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What is the malignant potential of the hamartomatous gastrointestinal polyps seen in Peutz-Jegher's syndrome?
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While these patients face a higher risk for development of a carcinoma, it is not related to the polyps. Rather, these unfortunate patients incur an increased rate of malignancy in other organs such as the breast or pancreas.
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On what chromosome is the gene for familiar adenomatous polyposis located?
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Chromosome 5q21.
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What is the name of the syndrome characterized by the combination of adenomatous polyposis of the colon and associated tumors of the central nervous system, typically gliomas?
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Tucot's syndrome.
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Where is the allele called DCC (deleted in colon cancer) located?
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On chromosome 18q where it encodes for a molecule in the cell adhesion molecule family. The expression of this protein is absent or markedly reduced in almost 75% of colon cancers.
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In some patients with a genetic predisposition to development of adenocarcinoma of the colon, there is an abnormality of the DNA on chromosome 2. What is the abnormality?
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Microsatellite instability.
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In a patient with an Astler-Coller state B2 carcinoma of the colon, what would you expect the approximate 5-yr survival rate to be?
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Remember the Astler-Coller staging system:
Stage A- limited to the mucosa Stage B1- tumor extension into the muscularis propria without penetration or involved nodes Stage B2- tumor penetrates through the muscularis propria without involvement of regional lymph nodes Stage C1- penetration into the muscularis propria but not through it with positive lymph nodes Stage C2- penetration by tumor through the muscularis propria with associated involved lymph nodes Stage D- distant metastatic spread. A B2 tumor is associated with an approximate 50% five-year survival. |
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What is another name for hereditary non-polyposis colorectal cancer syndrome?
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Lynch syndrome
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Where in the colon do most carcinomas in the Lynch syndrome occur?
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They are typically right-sided
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What is the name of the syndrome composed of colorectal carcinoma with multiple sebaceous tumors and keratoacanthomas?
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The Muir-Torre syndrome
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What are the components and inheritance of Cowden's syndrome?
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It is characterized by the presence of oral mucosal papillomas, trichilemmomas of the face and acral hyperkeratosis. Approximately 1/3 of the patients have intestinal polyposis. Inheritance is autosomal dominant.
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What is the Cronkhite-Canada syndrome?
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This syndrome is characterized by the presence of numerous gastrointestinal polyps and abnormalities of the nails termed onychodystrophy.
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What 3 infectious forms of esophagitis are most common in AIDS patients?
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Candida albicans, Herpes simplex virus and cytomegalovirus.
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What are the most common risk factors for Candida albicans esophagitis?
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Immunosuppression, most commonly due to AIDS or cancer chemotherapy, or suppression of normal oropharyngeal flora by antibiotic use.
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Comparing Candida albicans esophagitis in AIDS patients to cancer patients receiving immunosuppressive chemotherapy, whcih group is more likely to have disseminated infection?
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Patients receiving chemotherapy. Isolated lymphopenia, seen in AIDS patients, limits Candida infection to the superficial layers of the esophagus, while chemotherapy-induced granulocytopenia is far more likely to allow dissemination of infection.
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What underlying medical conditions increase the risk of developing Candida albicans esophagitis?
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Gastric hypochlorhydria, diabetes mellitus, adrenal dysfunction, alcoholism and conditions associated with impaired esophageal peristalsis such as achalasia, esophageal cancer and scleroderma.
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How should an immunocompetent patient who recently received a course of antibiotic therapy and how has Candida esophagitis be treated?
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A non-absorbable oral agent such as nystatin is usually adequate.
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How should an AIDS patients with oral thrush, dysphagia and Candida esophagitis be treated?
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A systemically absorbable anti-fungal agent such as fluconazole or ketoconazole should be given. Gastric achlorhydria may impair the absorption of ketoconazole, but this can be overcome with concurrent ingestion of a phosphoric acid-containing cola beverage.
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How should a cancer patient with granulocytopenia and clear evidence of Candida esophagitis be treated?
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Intravenous amphotericin B can prevent and treat disseminated infection and it also is effective for systemic aspergillosis. Flucytosine may need to be added to amphotericin in life-threatening disease. Parenteral fluconazole is adequate for the treatment of candidiasis but does not cover aspergillosis.
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T/F: Non-candida fungal infections (eg Aspergillus, Blastomyces, Cryptococcus and Histoplasma) of the esophagus occur only in severely immunocompromised individuals.
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True
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T/F: Biopsies of esophageal ulcers looking for Herpes simplex infection should be targeted toward the center of the ulcer, as the heaped-up margins are typically composed of normal epithelial cells.
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False. The opposite strategy is true. Herpes simplex preferentially infects the epithelial cells which are present at the ulcer margins.
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T/F: In the absence of imunosuppression, an individual with nasolabial herpetic lesions and concurrent esophageal symptoms should have endoscopic biopsies and cultures done before a diagnosis of Herpes esophagitis can be made.
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False. In this situation, a clinical diagnosis of Herpes esophagitis is likely enough to treat empirically.
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How should Herpes simplex esophagitis be treated?
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Intravenous or high dose oral acyclovir for 7-10 days is generally effective. The development of resistant strains of Herpes simplex may necessitate the use of intravenous foscarnet. Oral famciclovir or valacyclovir have excellent bioavailability and may replace acyclovir in the future.
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T/F: Biopsies and culture specimens of esophageal ulcers, looking for cytomegaloviral (CMV) infection, should be targeted toward the center of the ulcer, as the heaped up edges are typically normal epithelial cells.
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True
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T/F: A patient with known CMV infection who presents with new symptoms of dysphagia and odynophagia should be treated empirically for a diagnosis of CMV esophagitis w/o further diagnostic evaluation.
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False. Nausea, vomiting, fever, epigastric pain, fever and weight loss are usually the more prominent symptoms than are classic symptoms of esophageal infection. Endoscopy should be done to rule out a separate explanation for esophageal symptoms.
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T/F: Patients with reactivation of Herpes zoster infection on the chest wall who also have esophageal symptoms should be suspected of having zoster-associated esophagitis.
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True. Zoster associated esophageal ulcers that endoscopically resemble those of Herpes simplex infection have been reported in this setting. These ulcers generally resolve with resolution of the skin eruptions.
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What is the most common pathophysiology of esophageal involvement in tuberculosis?
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Esophageal tuberculosis is most often the result of spread from an infected mediastinal lymph node. Infection reaches the esophagus by way of a fistula or due to lymphatic obstruction. This infection has become much more common as a complication of AIDS.
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What 2 viral infections are associated with gastric ulcers?
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Cytomegalovirus and Herpes simplex type I.
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A biopsy from a gastric ulcer reveals granulomas. What is the differential diagnosis?
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Infection (tuberculosis, histoplasmosis), Crohn's disease, sarcoidosis and foreign body reaction.
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Menetrier's disease is associated with what viral infection?
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Menetrier's disease in childhood is usually associated with gastric cytomegalovirus infection.
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An acutely ill patient is found to have purulent gastric inflammation on endoscopy. What is the diagnosis?
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Phlegmonous gastritis. This has been associated with alpha-hemolytic streptococcus in about 50% of the cases. A variant, emphysematous gastritis, results from infection with gas-producing organisms.
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What part of the GI tract is most commonly involved in mucormycosis?
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The stomach. The typical lesion is a deep bleeding ulcer with black indurated edges.
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A 23-yr old woman develops severe abdominal pain after eating sushi. Upper endoscopy reveals a small worm protruding from the mucosa. What is the diagnosis?
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Anisakidosis. This is acquired by eating sushi or other types of raw fish.
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T/F: Histoplasmosis of the GI system mainly affects the stomach.
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False. The colon and the ileum are the most common sites. The stomach is rarely involved.
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What food is usually implicated in the vomiting syndrome caused by Bacillus cereus?
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Fried rice.
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Improperly canned products may contain what potentially lethal infection?
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Clostridium botulinum. Its spores are resistant to heat and its neurotoxin can block acteylcholine at the neuromuscular junction, resulting in fatal respiratory muscle paralysis.
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What potentially lethal infection is usually transmitted by drinking unpasteurized or poorly pasteurized milk/milk products?
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Listeria monocytogenes. Populations at risk include pregnant women and immunosuppressed persons. Meningitis can be a fatal occurrence with this infection.
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What is the primary etiologic agent for large food-borne outbreaks of bacterial gastroenteritis in the US?
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Salmonella.
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Name 3 clinical syndromes associated with neurologic abnormalities (parathesias, ataxia, hypotension, seizures, muscle paralysis) that occur following ingestion of toxin-containing fish.
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Puffer fish poisoning (tetodotoxin), paralytic shellfish poisoning (saxitoxin) and ciguatera poisoning (ciguatoxin).
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What is the most common fish poisoning in the US?
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Ciguartera. Commonly seen in Florida, Hawaii and the Caribbean.
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Which contaminated fish poisoning may cause flushing, vertigo, and burning sensation and is effectively treated with antihistamines?
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Scromboid. Histamine like substances cause the symptoms and histamine levels can be assayed in the implicated fish. Spoiled tuna, mackerel and skipjacks are often implicated. If any of these fish has an unpleasant odor or clouded eyes, it should be avoided.
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What strain of E. coli may cause hemorrhagic colitis and hemolytic uremic syndrome and has a high fatality rate?
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E. coli 0157:H7, also called enterohemorrhagic E. coli. It does not invade epithelial cells but produces at least two cytotoxins. It is usually associated with consumption of inadequately cooked ground beef or raw milk.
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What are differences between the enterotoxins produced by Vibrio cholera and Clostridium perfringens?
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Clostridial enterotoxin has maximal activity in the ileum and minimal activity in the duodenum, just the opposite of cholera toxin.
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What is the most common vehicle for Clostridium perfringens gastroenteritis?
|
Meat or poultry that is cooked, stored and then reheated. Heat-resistant spores that survive the cooking process germinate w/in the food during the cooling period. On reheating, sporulation of the cells occurs with subsequent enterotoxin production.
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If an individual travels to an underdeveloped country and develops fever and bloody stools, what is the most likely infection?
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Shigellosis. While enterotoxigenic E. coli accounts for most cases of traveler's diarrhea worldwide, it produces a non-bloody diarrhea.
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T/F: A causative agent is found in most patients with traveler's diarrhea suffering from prolonged diarrhea.
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False.
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Which newly described protozoan parasite is responsible for traveler's diarrhea in visitors to a number of underdeveloped countries?
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Cyclospora cayetanensis
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What 2 parasitic infection are hazards to travelers to St. Petersburg, Russia (formerly Leningrad)?
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Giardia lamblia and Cryptosporidium
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What is the approach to patients with persistent traveler's diarrhea in whom a specific pathogen cannot be identified?
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1) Treatment with an antibiotic directed at common bacterial pathogens.
2) Empiric course of antiprotozoal therapy if the above approach does not alleviate symptoms. 3) Endoscopic evaluation if the above fails |
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What is the current recommendation for the treatment of traveler's diarrhea?
|
For mild to moderate diarrhea (fewer than 4 bowel movement per day without blood or fever), either loperamide or bismuth subsalicylate can be used effectively. For more severe diarrhea, an antimicrobial drug should be used, usually a fluroquinolone or trimethoprim-sulfmethoxazole. Antimotility agents should be not be used when bloody stools or high fever are present.
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What is the risk of using antibiotics in patients with uncomplicated, nontyphoidal Salmonella gastroenteritis
|
It increases the incidence and duration of intestinal carriage of the organism
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With what 9 clinical disorders should antibiotics definitely be used when Salmonella gastroenteritis is diagnosed?
|
1) Lymphoproliferative disorders
2) Malignant disease 3) Immunosuppressed hosts (AIDS, congenital or acquired form) 4) Transplant patients 5) Abnormalities of the cardiovascular system - prosthetic heart valves, vascular grafts, aneurysms, rheumatic or congenital valvular heart disease 6) Foreign bodies implanted in the skeletal system 7) Hemolytic anemias 8) Extreme ages of life 9) Severe sepsis |
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What condition predisposes to Yersinia enterocolitica septicemia?
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Iron overload states, such as hemochromatosis, cirrhosis and hemolytic processes
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What intestinal infection can mimic acute appendicitis?
|
Yersinia enterocolitica. This infection is most common in children. Abdominal pain frequently localizes to the right lower quadrant with peritoneal signs, mimicking acute appendicitis.
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What infection is associated with raw or improperly stored seafood or food contaminated with seawater?
|
Vibrio parahemolyticus
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What is the cause of tropical sprue?
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Current evidence suggests that tropical sprue results from an infectious disease of the small intestine caused by several offending agents, all of which are toxigenic strains of coliform bacteria, including Lebsiella penumoniae, Enterobacter cloacae and E. coli. Travelers who acquire tropical sprue persist with bacterial contamination after return to a temperate climate until antibiotic treatment is given.
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What is the treatment of tropical sprue?
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Tetracycline or non-absorbable sulfonamides given for several months. Additionally, daily oral folic acid and weekly parenteral B12 should be given when megalobastic anemia is present.
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What symptoms may precede gastrointestinal complaints in Whipple's disease?
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Arthralgias and fever. Migratory arthralgias of the large joints may precede the onset of diarrhea by several years.
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What is the diagnostic procedure of choice for Whipple's disease?
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Upper endoscopy with multiple biopsies of duodenum or proximal jejunum. Biopsies show infiltration or the lamina propria with PAS-positive macrophages containing Gram-positive, acid-fast negative bicilli.
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In the absence of histologic evidence of Whipple's disease on small bowel biopsy, what further testing can be used to detect Tropheryma whippelii?
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Polymerase chain reaction of biopsied tissue.
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Why should rectal biopsy not be used to diagnose Whipple's disease?
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PAS-positive macrophages resembling those seen in Whipple's disease may be found in the rectal lamina propria of normal people and in patients with benign conditions such as melanosis coli and colonic histiocytosis.
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What condition resembles Whipple's disease histologically?
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Intestinal infection with Mycobacterium avium intracellulare in patients with AIDS. The histologic lesions in these two conditions are similar; however, T, whippelii will not take up acid-fast stain.
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What is the most serious sequela in a patient treated for Whipple's disease?
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Neurologic sequelae, including irreversible dementia, may occur several months or years after successful treatment. This suggests that, unless an antibiotic that readily penetrates the blood-brain barrier is used, the central nervous system may provide a safe haven for residual Whipple's bacilli.
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What is the treatment of Whipple's disease?
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Double-strength trimethoprim-sulfamethoxazole twice daily for a year. This antibiotic readily crosses the blood-brain barrier and should effectively eradicate central nervous system involvement. For patients intolerant of this drug, a third-generation cephalosporin such as ceftriaxone can be used.
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What is the treatment of a central nervous system relapse in Whipple's disease?
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Repeat initial therapy with double-strength trimethoprim-sulfamethoxazole. If unsuccessful, chloramphenicol, which also results in high central nervous system concentrations, is given at a dose of 250 mg four times a day.
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What is the appearance of cryptosporidia on mucosal biopsy specimens?
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On light microscopy, the trophozoites appear as multiple, round, tiny basophilic bodies lying on the brush border of eneterocytes.
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After successful treatment of intestinal cryptosporidiosis in immunocompromised patients, what causes recurrence?
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Seeding from the biliary tract, where cryptosporidia can also reside.
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How is Isospora belli detected in the stool?
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Oocysts in the stool fluoresce bright yellow with auramine-rhodamine stain and appear pink with red-purple sporocysts on a modified acid-fast stain.
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What area of the intestinal tract is most commonly involved in histoplasmosis?
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Terminal ileum
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T/F: Histoplasmosis can occur in an immunocompetent host.
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True. Histoplasmosis is a very common infection in the midwestern and south-central US, where 80% of inhabitants are infected. However, GI disease is seen in only immunocompromised individuals.
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When should infection with microsporidiosis be considered?
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When no other pathogens are identified in an immunocompromised patients with severe diarrhea, malabsorption and weight loss.
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What is the most specific diagnostic tool for detecting microsporidia in intestinal biopsy specimens?
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Electron microscopy. Under light microscopy, the organism is difficult to identify.
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What type of surgery increases susceptibility to infection with salmonella?
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Gastric surgery resulting in achlorhydria.
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Why should patients with underlying liver disease be warned about eating raw seafood, especially raw oysters?
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Vibrio vulnificus infection can be acquired through direct consumption of seafood, usually raw oysters. Subsequent septicemia has a 50% mortality rate. This infection can be lethal in patients with underlying liver disease.
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What severe intestinal complications may occur in typhoid fever?
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Perforation (3% of cases) and hemorrhage (20% in pre-antibiotic era). These events are not related to the severity of the disease and tend to occur in the same patient, with bleeding serving as a harbinger of a possible perforation.
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What infectious agent causes most cases of sporadic bacterial gastroenteritis in the US?
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Campylobacter jejuni. This accounts for 4% to 11% of all diarrhea cases in the US
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The most common sites for intestinal involvement of tuberculosis are:
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Distal ileum and cecum
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What small intestinal parasite, once ingested, has part of its life cycle in the lungs?
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Ascaris lumbricoides. Duodenal larvae migrate through the epithelium into portal venous blood and eventually reach the lungs causing a pneumonitis. Larvae then migrate up the bronchioles to the pharynx, are swallowed and develop into adults in the small intestine.
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What tapeworm may cause vitamin B12 deficiency?
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Diphyllobothrium latum. The worm ingests vitamin B12 and thus competes with the host for available vitamin B12
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What parasitic infestation may result in variceal bleeding?
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Shistosomiasis. Granulomatous fibrosis occurs around entrapped ova in pre-hepatic portal venules with relative sparing of hepatic parenchyma. This results in presinusoidal portal hypertension.
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What are the types of diarrheagenic E. coli?
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Enterotoxigenic (ETEC), Enteropathogenic (EPEC), Enteroinvasive (EIEC), Enterhemorrhagic (EHEC), Enteroaggregative (EAEC) and Diffusely adherent E. coli.
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What regions of the GI tract do various species of E coli tend to involve?
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Enterotoxigenic - small intestine
Enteropathogenic - small intestine Enteroinvasive - large intestine Enterohemorrhagic - large intestine Enteroaggregative - unknown |
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What clinical syndromes are associated with ETEC?
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Diarrhea in small children in the developing world and traveler's diarrhea
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How does enteropathogenic E. coli (EPEC) cause disease?
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It causes adherence and effacement of enterocytes.
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T/F: Stools from patients with enterotoxigenic E. coli are bloody.
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False. They are watery w/o blood or pus.
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What is the site of infection with enteroinvasive E. coli?
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The colonic mucosa. Ulceration may occur as a result of this infection.
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What other member of the Enterobacteriaceae is enteroinvasive E. coli like?
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Shigella. In fact, it may be misidentified as Shigella.
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Which E. coli strain is associated with hemolytic-uremic syndrome?
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Enterohemorrhagic E. coli (E. coli 0157:H7)
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What are the components of hemolytic-uremic syndrome?
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The classic triad includes: 1) acute renal failure; 2) thrombocytopenia and 3) microangiopathic hemolytic anemia.
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What is the classic histopathology characteristic of EHEC?
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Hemorrhage and edema in the lamina propria of the colon. On barium enema, a thumbprinting pattern in the ascending and transverse colon may be seen as a result of edema and mucosal hemorrhage.
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What might colonic biopsy from a patient with EHEC show?
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Biopsies from many patients have shown focal necrosis and infiltration of neutrophils. Pseudomembranes may also be sseen.
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What is the major virulence factor of EHEC?
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Shiga toxin
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How is E. coli 0157:H7 transmitted?
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It is usually transmitted via contaminated beef but may also be transmitted through contaminated juice, water and vegetables. Person-to-person transmission is also possible. The main reservoir is cattle.
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T/F: There's a seasonality associated with EHEC infection.
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True. In the developed countries of the northern hemisphere, it is more common in the summer.
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What is the infectious dose of E. coli 0157:H7?
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One hundred to 200 organisms are sufficient to cause infection.
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How long is the organism shed in the stool?
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One study showed that 66% were culture-negative after 7 days, even in the absence of antibiotic therapy
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What are the frequencies of the various syndromes for diagnosed cases of E. coli 0157:H7
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10% nonbloody diarrhea; 90% hemorrhagic colitis
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What percentage of patients infected with E. coli 0157:H7 develop hemolytic-uremic syndrome (HUS)?
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In patients <10 years old, approximately 10% develop HUS. It appears to be less common in adults.
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T/F: All individuals with E. coli 0157:H7 should be treated with antibiotics.
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False. There is evidence that this may increase the incidence of HUS in children. Anti-diarrheal agents may also increase the risk of HUS.
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How does infection with E. coli 0157:H7 present?
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The initial complaint is that of nonbloody diarrhea and vomiting in about half of these patients. In some individuals, this may be preceded by crampy abdominal pain and fever. After 1 to 2 days, the diarrhea becomes bloody and the abdominal pain may increase. The bloody diarrhea lasts about 4 to 10 days.
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What is the clinical outcome in patients infected with E. coli 0157:H7?
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Most patients recover without apparent sequelae. In those <10 years old, approx 10% develop HUS. Three to five percent of affected children will die and 12% to 30% experience renal insufficiency, hypertension or central nervous system manifestations.
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How is E. coli 0157:H7 detected in the clinical lab?
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The Center for Disease Control and Prevention recommends that bloody diarrheal stools and stools from patients with HUS be screened for E. coli 0157:H7 on sorbitol maconkey agar. This organism does not ferment sorbitol and thus is colorless on this medium.
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What are the species and groups of Shigella?
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S. dysenteriae (group A)
S. flexneri (group B) S. boydii (group C) S. sonnei (group D) |
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Which species of Shigella is the most common isolate in the US?
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S. sonnei (60-80%)
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How does Shigella produce disease?
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Virulent Shigella invade the intestinal mucosa. This is the primary virulence factor. Shigella spp. can also produce an exotoxin, the shiga toxin.
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T/F: Blood cultures are usually positive with Shigella infection.
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False. The organism rarely invades beyond the mucosa.
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Where in the intestinal tract does Shigella infection occur?
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W/in 12 hours, the bacteria transiently multiply within the small bowel. During this time, fever and abdominal pain may occur. After a few days, the bacteria are found diffusely in the colon producing microabscesses which coalesce and mucosal ulcerations. When the bacteria are in the colonic stage, urgency, tenesmus and bloody mucoid stools occur.
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T/F: There is a seasonality to Shigella infection.
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True. It is more common in the summer.
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What is the typical clinical course of Shigella infection?
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Early, fever and abdominal cramping occur and are followed by voluminous watery diarrhea (while bacteria are in the small bowel). Later, there is a decrease in fever but increase in stools of smaller volume. After a few days, bloody mucoid stools may occur with fecal urgency and tenesmus (when bacteria are in the colon stage).
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How often do patients with Shigella develop fever or bloody stools?
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Nearly all patients with Shigella experience abdominal pain and diarrhea. Fever occurs in about 50%, mucus in stools in about 50% and grossly bloody stools in about 40%.
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What are the laboratory findings in patients with Shigella?
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Sometimes the peripheral white blood cell count is elevated. Microscopic evaluation of feces show may polymorphonuclear leukocytes. On stool culture, since Shigella does not ferment lactose, colonies appear colorless on lactose-containing media. Serologic studies are not helpful in establishing the diagnosis but may be an epidemiologic tool for defining the extent of an epidemic.
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T/F: Patients with Shigella infections should receive antibiotic treatment.
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True. All patients should be treated in order to shorten the duration of illness and to decrease spread of the infection
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What antibiotics are used to treat Shigella?
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Trimethoprim-sufamethoxazole if acquired in the US (160/800 b.i.d for 3 to 5 days). If acquired outside of the US or if resistant to trimthoprim-sulfamethoxazole, a fluroquinolone can be used.
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Untreated, how long do patients with Shigella excrete the microorganisms?
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About 1 to 4 weeks. The organism is carried in the colon. Long-term carriers are uncommon. Carriers usually respond to antibiotic treatment.
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What host factor lowers the infectious dose in Salmonella infections?
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Lack of gastric acid. Acid is the first line of deffense in Salmonella infections.
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Describe the histology of nontyphoidal Salmonella infections.
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Massive neutrophil infiltration in both large and small bowel mucosa. Degranulation of neutrophils contributes to inflammation.
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Who is at increased risk for infections due to Salmonella?
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AIDS patients, patients following organ transplantation or with a lymphoproliferative disease or chronic granulomatous disease, those with phagocytic overload (bartonellosis, malaria and schistosomiasis), sickle cell disease and neonates. In addition, those with decreased stomach acid, those receiving antibiotics and those with inflammatory bowel disease are at an increased risk.
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Describe the clinical features of Salmonella gastroenteritis?
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Symptoms (nausea, vomiting, and diarrhea) begin within 48 hours of ingestion of contaminated food or water. The diarrhea varies in volume but most are without blood or mucus. Fever and abdominal cramping occur in about 90% of cases. Fever resolves in 2 to 3 days and the diarrhea is usually self-limiting.
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What is seen in the laboratory evaluation of a patient with Salmonella?
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Fecal leukocytes are seen on microscopic evaluation of stools. Salmonella sp. are nonlactose fermenters; therefore, the colonies appear colorless on lactose-containing media. Less than 5% of immunocompetent individuals will have positive blood cultures with nontyphoidal Salmonella infections.
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How long will a patient carry Salmonella after resolution of Salmonella gastroenteritis?
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Nontyphoidal strains may be carried about 4 or 5 weeks. Less than 10% will still carry the organism by 10 to 12 weeks.
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What are the recommendations for treatment of Salmonella gastroenteritis?
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Otherwise healthy persons with mild symptoms should not be treated with antibiotic because that may lead to longer carriage of the microorganism. Those with infection severe enough to be hospitalized or with the previously mentioned underlying conditions should be treated with fluroquinolones or trimethoprim-sulfamethoxazole.
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What is the reservoir of Campylobacter jejuni?
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Campylobacter is a zoonosis. It is most commonly acquired from poultry but may also be transmitted through raw milk, other dairy products and undercooked meats.
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T/F: There is a seasonality to Campylobacter jejuni infections.
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True. Infections occur year round, but increase in summer and early fall.
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What are the sites of tissue injury in Campylobacter infections?
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Jejunum, ileum and colon. Inspection shows diffuse, bloody edematous and exudative enteritis.
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What is seen on laboratory evaluation of a patient with Campylobacter jejuni infection?
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Gram stain of stool shows Gram-negative (gull wing) bacteria. The sensitivity of diagnosis with Gram stain is 50% to 75%. Stool cultures must be done using special media under microaerophilic conditions. Blood cultures are positive in less than 1%.
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What are some of the sequelae of Campylobacter jejuni infection?
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There have been rare reports of septic abortion, cholecystitis, pancreatitis and cystitis. Those with immunoglobulin deficiencies may develop recurrent infection. A reactive arthritis may occur several weeks after infection in persons with HLA-B27. Guillian-Barre syndrome is uncommon. Of those with Guillian-Barre syndrome, 10% to 40% occur following C. jejuni infection.
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Describe the pathology of lesions seen with Entamoeba histolytica infection.
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Colonic lesions range from nonspecific thickening of the mucosa to the classic flask-shaped ulcer. 20-50% of patients have classic ulcers extending through the mucosa and muscularis mucosa and into the submucosa.
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Describe the extraintestinal pathology of Entamoeba histolytica.
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Liver abscesses containing proteinaceous debris surrounded by a rim of trophozoites. Pleuropulmonary amebiasis can occur as a complication of amebic liver abscess. Intraperitoneal rupture of liver abscesses can also occur. Rarely pericardial, genitourinary and cerebral amebiasis occurs.
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How is infection with E. histolytica treated?
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Ten day course of metronidazole followed by an intraluminal agent such as diloxanide furoate or paromomycin.
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What pathologic lesions are seen with Cryptosporidium infection?
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In immunocompromised patients, cryptosporidium can be found on biopsies taken throughout the intestinal tract, hepatobiliary system and respiratory tract. In otherwise healthy individuals, it is mostly confined to the intestine. Villous atrophy, blunting, fusion or loss of villi, crypt hyperplasia and lengthening have all been observed. There may also be infiltration of the lamina propria with lymphocytes, neutrophils, plasma cells and macrophages.
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How is Cryptosporidium diagnosed in the laboratory?
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Stools should be examined by modified acid fast stain. Intestinal biopsy can also be performed.
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How is infection with Cryptosporidium prevented?
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Water filtration. The organism is resistant to chlorination.
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What organisms is associated with most cases of antibiotic-associated pseudomembraneous colitis?
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Clostridium difficile.
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How is C. difficile colitis treated?
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A 7-10 days course of oral metronidazole or oral vancomycin. For cases of suspected relapse, after reconfirmation of the diagnosis, retreatment with the standard course of oral metronidazole or vancomycin is recommended.
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What organism is most commonly associated with recurrent pyogenic cholangitis?
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Clonorchis sinensis
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Name four causes of multiple liver abscesses.
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Gallstones, obstructing carcinoma of the bile duct, primary sclerosing cholangitis and congenital biliary anomalies such as Caroli's disease.
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Which lobe of the liver are liver abscesses most commonly found?
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Right
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How do amoeba cause focal infection of liver cells?
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Amoeba multiply and block intrahepatic portal nodules.
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In the setting of an amoebic liver abscess, a sudden rise in billirubin suggests what two clinical entities?
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Superinfection of abscess rupture into the pertitoneum.
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In addition to intravenous antibiotics, what adjuvant therapy is necessary to ensure amoebic eradication?
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A 20-day course of an intraluminal antibiotic such as iodoquinol. This is given in order to eradicate amoeba persisting in the gut.
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Alkaline phoshatase elevation disproportionate to bilirubin elevation is indicative of what clinical entity?
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Space occupying lesion of the liver.
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A histologic finding of a liver abscess showing sulfur granules is suggestive of what organism?
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Actinomyces israeli
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What are the intermediate hosts in hydatid disease?
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Man, sheep and cattle
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What parasite can predispose to intrahepatic gallstones?
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Ascaris lumbricoides
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What is the intermediate host for Fasciola hepatica?
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Lymnaeca trunculata - snail. Patients are infected by eating watercress infected with ingested forms of the fluke.
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When is surgical treatment indicated for patients with infestation of the biliary tract by Clonorchis sinensis (Chinese liver fluke)?
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Surgical treatment is reserved for complications, such as biliary obstruction, due not only to the parasites themselves, but also to secondary formation of stones and acute cholangitis. Some patients present with pancreatitis, presumably caused by passage of the stones or the worms. In addition to cholecystecomy and clearing the bile ducts of stones and flukes, improved biliary drainage by choledochoduodenostomy or transduodenal sphincteroplasty is thought to reduce the rate of recurrent biliary obstruction, which otherwise exceeds 40%.
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What is one antibiotic that has been shown to have high concentration in bile and is useful in treating cholangitis?
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Ciprofloxacin.
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What antibiotic can lead to the development of biliary sludge?
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Ceftriaxone precipitates a calcium salt that has the ultrasonic appearance of biliary sludge.
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What factors are associated with the development of black pigment stones?
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Chronic hemolysis, as can occur in hereditary spherocytosis, thalassemia and the presence of mechanical heart valves; cirrhosis; total parenteral nutrition; and, advanced age.
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What bacterial infection and anatomical deformity play a role in the formation of brown pigment stones?
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Escherichia coli and a juxtapapillary duodenal diverticulum.
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What bacterial enzyme is responsible for hydrolysis of conjugated bilirubin and may play a role in the development of pigmented stones?
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Beta-glucuronidase.
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What bacteria can cause acute cholecystitis and also be non-pathogenic in a carrier state?
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Salmonella.
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Name a virus and parasite that predispose to acute cholecystitis in an immunocompromised host.
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Cytomegalovirus and cryptosporidium.
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What are the three most common organisms isolated from blood cultures in patients with cholangitis?
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Escherichia coli, Klebsiella, and Pseudomonas. Anaerobes are isolated in approximately 15%.
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What is the mechanism of biliary obstruction in tuberculosis?
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Obstructive jaundice is a rare complication of tuberculosis. The obstruction is caused by tuberculous infection in lymph nodes in the porta hepatis or the retroduodenal area that compresses the bile duct.
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Eosinophilia, elevated alkaline phosphatase and cholangiography findings of filamentous filling defects with blunted tips in the bile duct suggest what infection?
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Clonorchis sinensis or Fasciola hepatica.
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Which of the following primary duct stones has the highest culture rate of bacteria - black, brown, or cholesterol?
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Brown.
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Charcot's triad plus what other two clinical features defines Reynold's pentad?
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Hypotension and altered mental status.
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In Oriental cholangitis, which side of the hepatic ductal system most commonly develops strictures and intrahepatic stones?
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The left hepatic duct due to its more acute angle at the bifurcation.
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Bacillary angiomatosis with peliosis is caused by what organism?
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Bartonella henselae or Bartonella quintana.
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What is the treatment of Bacillary angiomatosis with peliosis in a patient with fever, abdominal pain and elevated liver tests?
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Antibiotic therapy with erythromycin or doxycycline.
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What species of Microsporidia is responsible for causing AIDS cholangiopathy?
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Enterocytozoon bieneusi
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What are the 5 most common viral infections of the pancreas?
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Mumps, Coxsackie B. Enterovirus, Epstein-Barr Virus, and Cytomegalovirus. In addition, the Hepatitis viruses A, B and C have also been reported to infect the pancreas.
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What fungal infections can involve the pancreas and/or cause pancreatitis?
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Aspergillosis and Actinomycosis.
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What 4 parasitic infestations ma involve the pancreas?
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Ascaris lumbricoides, Echinococcus granulosis, Giardia lamblia and Plasmodium falciparum.
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T/F: The most common bacteria that cause pancreatic infections are Gram-negative enteric organisms.
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True. Escherichia coli, enterobacter and enterococcal species occur most commonly; however, Staphylococcus aureus is also frequently isolated.
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A visiting shepherd from South America is transferred to your service with fevers, weight loss and diarrhea. A CT scan of the abdomen reveals a large calcified cyst with fenestrations in the pancreas and several smaller cysts nearby. What is your diagnosis?
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Hydatid cysts of the pancreas.
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What organism is responsible for hydatid cysts disease?
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Echinococcus granulosis, or occasionally E. multiocularis, a parasitic worm that normally resides in the intestine of dogs.
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How is the diagnosis of hydatid disease made?
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Diagnosis is based on history of exposure from endemic areas and characteristic radiographic findings. A negative serologic test does not necessarily exclude the diagnosis.
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What is the treatment of hydatid cysts of the pancreas?
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Surgical excision, if technically possible, or high dose mebendazole or albendazole are the mainstays of treatment.
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T/F: The signs and symptoms of an acute pancreatic infection differ from those that occur with acute pancreatitis.
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False. Epigastric pain, fever, nausea and/or vomiting are frequent symptoms. Signs include leukocytosis and elevations in serum amylase and lipase.
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How does the human immunodeficiency virus affect the pancreas in 3 ways?
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Indirectly through secondary infections (Mycobacterial spp, fungi) infiltrative processes (lymphoma, Kaposi's sarcoma) or drugs used in its treatment (2', 3' dideoxyinosine).
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T/F: Oral aphthous ulcerations may be seen in patients with Crohn's disease or ulcerative colitis.
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True. Oral aphthae occur in at least 10% of patients with active ulcerative colitis and typically resolve when this disease goes into remission. Aphthous ulcerations occur more commonly in Crohn's disease.
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Kidney stones develop with increased frequency in Crohn's disease. What types of stones may be seen?
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Oxalate kidney stones are seen in 5% to 10% of Crohn's disease patients. Steatorrhea promotes excess colonic absorption of oxalate which leads to the development of oxalate kidney stones. Urate stones are seen less frequently and are often associated with the presence of an ileostomy and/or dehydration.
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T/F: Crohn's disease patients are predisposed to gallstone formation.
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True. Fifteen percent to 30% of patients with small bowel Crohn's develop gallstones. Ileal dysfunction or resection leads to alterations in the bile salt pool.
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Which patients with Crohn's disease are most at risk for the development of amyloidosis?
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Those with longstanding suppurative or fistulous complications.
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Amyloidosis is an unusual but life threatening complication of inflammatory bowel disease. What is the most common presentation of this rare complication?
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Nephrotic syndrome. Amyloid may also be diffiusely deposited in bowel, spleen, liver, heart, and thyroid.
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T/F: Primary sclerosing cholangitis is associated with both ulcerative colitis and Crohn's disease.
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True. Primary sclerosing cholangitis is seen less frequently in Crohn's disease. With either disease, it can be complicated by the development of cholangiocarcinoma.
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In what trimester of pregnancy are relapses most frequently seen in women with Crohn's disease?
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First trimester. Approximately 75% of women in remission remain in remission throughout pregnancy, while only 1/3 of women with active Crohn's disease at the time of conception will achieve remission during pregnancy.
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T/F: Crohn's disease almost always flare after delivery in recently pregnant women.
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False. The activity of the disease in the puerperium reflects disease activity at term.
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What % of Crohn's colitis involves the entire colon, exclusive of small bowel disease?
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25%. Crohn's disease involving the colon alone has more frequent involvement of the distal colon than those patients with ileocolitis. Only 1/4 of patients with Crohn's colitis exhibit skip lesions.
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T/F: "Skip" areas are characteristic of Crohn's disease. These areas appear normal grossly, radiologically, endoscopically and histologically.
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False. "Skip" areas of the intestine may have normal or abnormal histology.
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T/F: Involvement of the rectum in a patient with colitis rules out Crohn's disease.
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False. Although rectal sparing is characteristic of Crohn's disease and helps distinguish it from ulcerative colitis, the rectum can be involved.
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T/F: The siblings of a Crohn's disease patient are more likely to develop Crohn's.
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True. They are about 17 to 35 times more likely to develop Crohn's disease than the general population.
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T/F: The incidence of Crohn's disease is declining.
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False. Most recent studies throughout the world show a rising incidence of Crohn's disease and a declining incidence of ulcerative colitis.
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