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160 Cards in this Set
- Front
- Back
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What esophageal structures remain contracted even in the resting phase?
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upper (cricopharyngeal muscle) and lower (gastroesophageal junction) esophageal sphincters
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What type of mucosa does the esophagus have?
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Non-keratinized squamous epithelium
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What's in the submucosa of the esophagus?
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lymphatics, mucus glands, and blood vessels
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What's the musculature of the esophagus like?
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2 layers: inner circular and outer longitudinal with myenteric neural plexuses between the layers
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Where do esophageal malignancies/infections spread? Why?
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Rapidly spread into the posterior mediastinum because there's rich lymphatics and no serosa.
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What are esophageal "webs"?
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Mucosal rings found mostly in the upper esophagus of women over 40.
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What are mucosal rings called in the lower esophagus? Where exactly are they located?
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Schatzki's rings
Just above squamocolumnar junction |
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What is achalasia?
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3 abnormalities: aperistalsis, partial/incomplete relaxation of the LES with swallowing, and increased resting tone of the LES
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What's important to know when monitoring patients with achalasia?
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About 5% develop squamous cell carcinoma
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What are the two types of hiatal hernias?
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95% = sliding = protrusion of stomach above diaphragm with espisodic dysphagia
5% = paraesophageal/rolling = small non-axial part of stomach herniates |
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What is mallory-weiss syndrome?
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longitudinal tears at the gastroesophageal junction due to severe retching
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What causes esophageal varices? What's a major complication?
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Portal hypertension leads to collateral channels where portal and caval systems communicate (seen in 2/3 cirrhosis pts)
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What's a major complication of esophageal varicies?
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Rupture = massive hematemesis (=50% of deaths of advanced cirrhosis pts)
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What's the most common cause of esophageal inflammation?
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Reflux esophagitis (due to gastric reflux)
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What is a nosocomial cause of esophageal inflammation?
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Cytotoxic agents for chemotherapy and radiation
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What is Barrett's esophagus?
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replacement of normal distal stratified squamous epithelial mucosa by abnormal metaplastic columnar epithelium with goblet cells
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What causes Barrett's esophagus?
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long-standing gastroesophageal reflux
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Why's it important to monitor patients with Barrett's esophagus?
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There's a 30-40x increase in the incidence of adenocarcinoma and bleeding/strictures
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What is an important thing to note when looking at a histological sample of Barrett's esophagus?
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Look for dysplasia as a precursor to adenocarcinoma
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What are the most common benign tumors of the esophagus?
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Usually mesenchymal like leiomyomas (<3cm).
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What's the prominant malignant tumor seen in the esophagus? What's the prevalence of this tumor in the US?
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Squamous cell
6/100,000/yr |
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Where is the incidence of squamous cell ca of the esophagus the greatest?
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Northern China to Iran. Incidence = 100/100,000 and accounts for 20% of all cancer deaths
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What esophageal disorders can lead to malignancy?
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long standing esophagitis
achalasia Plummer-vinson syndrome |
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What dietary issues can lead to esophageal malignancy?
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Vitamin deficiencies (A, C, riboflavin, thiamine, pyridoxine, trace metals Zn/Mb)
Fungal contamination of food (mycotoxins) High consumption of nitrites/nitrosamines |
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What is the only known precursor for adenocarcinoma of the esophagus?
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Barrett's esophagus
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What is the American race prediliction for adenocarcinoma of the esophagus?
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More common in EuroAmer than AfroAmers (opposite of squamous)
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What is the most important form of heterotopia?
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When pancreatic tissue rests in the wall of the stomach/subserosa (<1 cm)
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Where can gastric cells be seen in the case of heterotopia?
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duodenum or more distal like Meckel's. May = bleeding.
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What is a diaphragmatic hernia?
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Not the same as hiatal! Caused by a weakness/hole in the diaphragm
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What is a complication of a congenital diaphragmatic hernia?
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fatal respiratory insult in the newborn due to herniation of the abdominal contents into the thorax in utero
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Occurrence and gender preference of pyloric stenosis?
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1/300-900 live births - some genetic concordance
3-4x more males |
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What's the presentation of pyloric stenosis?
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regurgitation and persistent, projectile vomiting in 2nd/3rd week of life
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Physical exam findings in pyloric stenosis?
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visible peristalsis and firm, ovoid mass in pylorus/distal stomach from hypertrophy/hyperplasia of muscularis propria
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What's the tx for pyloric stenosis?
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pyloromyotomy
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Why are most chronic gastritis cases missed?
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Most are asymptomatic
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What is gastritis?
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inflammation of the gastric mucosa
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What is acute gastritis associated with?
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high dose/prolonged use corticosteroids
Heavy alcohol/tobacco Many others! :) |
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What's the presentation of gastritis?
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Ranges from asymptomatic to gross hematemesis
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What is a gastric ulceration?
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Breach of mucosa that extends through the muscularis mucosa into the submucosa/beyond (unlike erosions, which are confined to the mucosa)
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Where are most peptic ulcers found?
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>98% are in the first part of the duodenum
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What's the lifetime likelihood for the development of peptic ulcers by gender?
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Men = 10%
Women = 4% (usually post-menopausal) |
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What conditions are duodenal ulcers more common in?
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COPD
Chronic renal failure hyperparathyroidism |
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What are possible factors in ulcerogenesis? (proposed mechanisms?)
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Chronic use of NSAIDS that suppress mucosal prostaglandin production (tobacco by same mechanism)
Physiologic/personality factors (stress) |
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What is Zollinger-Ellison syndrome?
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Gastrinoma which causes an increase in gastric acid which can lead to ulcers
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Where do most duodenal ulcers occur?
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Within 2cm of the pylorus
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What's the usual presentation of gastric ulcers?
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Gnawing, burning, or aching that's worse at night, occurs 1-3 hours after food, and is relieved by alkalis/food.
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What are cushing ulcers?
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Ulcers associated with intracranial pressure (named after American neurosurgeon)
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What are curling ulcers?
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Ulcers associated with burns or other severe trauma (named after English surgeon)
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What does chronic gastritis lead to?
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Atrophic gastritis, which = loss of acid and intrinsic factor. (mostly autoimmune)
There's usually no erosions associated with chronic. |
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Where does autoimmune gastritis occur and what causes it?
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Occurs in fundus/body
Assoc with autoantibodies to parietal cells (esp HKATPase and IF = pernicious anemia) |
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Where is autoimmune gastritis most often seen?
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Scandinavia
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What's the most common cause of chronic gastritis?
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H.pylori infection (infects 50% of americans >50 yrs)
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What are the clinical features of autoimmune gastritis?
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Hypochlorhydria with hypergastrinemia (due to compensatory hyperplasia of gastrin producing cells)
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What are the clinical features of non-autoimmune gastritis?
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Normal to low acid levels (never achlor since parietal cells aren't completely destroyed) and normal to slightly elevated serum gastrin levels
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What's Menetrier's disease?
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Profound hyperplasia of surface mucous cells with glandular atrophy
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What are common complications from Menetrier’s Disease?
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diarrhea, weight loss, bleeding, protein losing enteropathy, abdominal discomfort
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What's a problem that can arise from mucosal hyperplasia (such as that seen with Menetrier’s Disease)?
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mucosal hyperplasia may become metaplastic, which is set up for dysplasia------>carcinoma
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Are gastric polyps common?
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Nope - only seen in .4% of autopsies
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What are the 3 types of gastric polyps?
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1. hyperplastic (result of response to chronic inflamm)
2. fundic gland (small collections of dilated glands--thought to be hamartomas) 3. adenomatous (aka adenomas = true neoplasms, 40% malignant) |
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What is the most common malignancy in the stomach?
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90-95% = adenocarcinoma
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Where is there a high incidence of gastric cancer?
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**Japan**, Chile, Costa Rica, Colombia, China, Portugal, Iceland, Finland, and Scotland
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Which countries have a low incidence of gastric cancer?
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**U.S., U.K., Canada, Australia, New Zealand**
Also Greece, Honduras and Sweden |
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What percentage of cancer deaths are due to gastric cancer? (Why?)
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3% because 5 yr survival is <10%
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What are the two types of gastric carcinomas?
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Intestinal
Diffuse |
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Where is intestinal gastric carcinoma thought to stem from?
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Chronic gastritis (seen after 50 with 2:1 male predominance)
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Where is diffuse gastric carcinoma thought to stem from?
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De Novo from gastric epithelial cells (not decreasing in incidence, now = 50% of all. Usually poorly differentiated)
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What factors predispose for intestinal gastric carcinoma?
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Mainly environmental
diet (nitrites/preservatives, smoked/pickled foods, decreased antioxi/fruit intake) H.pylori infection Pernicious Anemia |
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Risk factors for diffuse gastric carcinoma?
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undefined: infection with H. pylori and chronic gastritis often absent
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What's important about ulcers on the lesser curvature of the stomach?
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"They're cancer until proven otherwise" because 40% of cancers involve the lesser curvature
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What's linitis plastica?
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A gross presentation of gastric carcinoma = "leather bottle stomach" with entire wall infultration
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What's an Omphalocoele?
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congenital defect of abdominal wall, allowing herniation of intestines into a membranous sac
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What's Meckel’s diverticulum?
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Most common congenital anomaly, resulting from failure of involution of omphalomesenteric duct = blind pouch 5-6 cm long in ileum 85 cm from the cecum
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What's important about Meckel’s diverticulum?
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may have heterotopic rests of pancreatic tissue and gastric mucosa, with resultant ulceration/bleeding
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Important notes pertaining to malrotation of large intestine?
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Cecum may be found anywhere in the abdomen and the colon is predisposed to volvulus
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What's Hirschsprung Disease?
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Lack of ganglion cells/ganglia in muscle wall/submucosa of affected intestine = megacolon in proximal bowel
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What parts of bowel are most commonly involved in Hirschsprung Disease?
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in most cases, only rectum and sigmoid are aganglionic
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When is Hirschsprung Disease
more common? |
4:1 male predominance
more frequent in newborns with other anomalies, such as VSD, hydrocephalus, and Meckel’s diverticulum (10% occur in Down’s syndrome) |
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Which areas of bowel can become ischemic?
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Either small, large, or both, depending on which artery's involved (celiac, superior or inferior)
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What's a loss frequent cause of ischemic bowel disease?
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mesenteric venous thrombosis
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Why do mural/mucosal infarcts of the small/large intestine occur?
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often result from physiologic hypoperfusion, e.g, shock states, blood loss
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What are the predisposing factors for arterial thrombosis which can lead to ischemic bowel disease?
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severe atherosclerosis (usually at mesenteric origin), systemic vasculitis, surgical accidents, hypercoagulable states
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What are the predisposing factors for arterial embolism which can lead to ischemic bowel disease?
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cardiac vegetations (endocarditis), MI with mural thrombosis, aortic atheroembolism, angiographic procedures
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What are the predisposing factors for venous thrombosis which can lead to ischemic bowel disease?
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hypercoagulable states (e.g., due to BCP, or Antithrombin III deficiency), sepsis, cirrhosis, abdominal trauma
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What are the predisposing factors for nonocclusive ischemia which can lead to ischemic bowel disease?
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cardiac failure, shock, dehydration, vasoconstrictive drugs
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What are the predisposing factors for the miscellaneous causes of ischemic bowel disease?
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radiation injury, volvulus, strictures
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What's the gross presentation of a transmural infarct of the bowel?
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dark red, hemorrhagic; due to reflow of blood into damaged area
begins in mucosa, extends outward within 18 - 24 hrs a thin fibrinous exudate is over serosa |
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What's the gross presentation of a mural/mucosal infarct of the bowel?
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multifocal lesions interspersed with spared areas (may not be visible from serosal surface)
may have a pseudomembrane due to infection chronic vascular insufficiency may mimic inflammatory bowel disease |
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Do you have to worry about ischemic bowel disease?
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Yup - people can die within hours due to vascular collapse so keep it in mind if people have predisposing factors
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How does transmural ischemia of the bowel present?
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acute onset of abd pain, occasionally with bloody diarrhea
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How does mural/mucosal ischemia of the bowel present?
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distention or GI bleeding, with gradual onset of abd pain
increased suspicion if pt has had episodes of hypoperfusion (e.g., cardiac failure or shock) |
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What's Angiodysplasia?
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of tortuous dilations of submucosal and mucosal blood vessels in the GI
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Where is Angiodysplasia seen and how common is it?
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seen most often in cecum or right colon
accounts for ~ 20% of lower GI bleeding |
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Development of Angiodysplasia?
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may be part of a systemic syndrome (e.g., Osler-Weber-Rendu syndrome or CREST) or develop de novo over many years
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Where are internal hemorrhoids located?
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above anorectal line, covered by rectal mucosa
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Where are external hemorrhoids located?
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below anorectal line, covered by anal mucosa
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What kind of poo do you get with dysentery?
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low volume, painful, bloody diarrhea
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Characteristics of secretory diarrhea?
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intestinal fluid is isotonic with plasma, persists with fasting
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Causes of secretory diarrhea?
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Infectious causes (epithelial damage): Rotavirus, Noro- (Norwalk/Calici-) virus, Enteric adenoviruses
Infectious causes (enterotoxin-mediated): E. coli, Vibrio cholerae, Bacillus cereus, C. perfringens Neoplastic: tumors which produce peptides or serotonin Excess laxative use |
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Characteristics of osmotic diarrhea?
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excessive osmotic forces due to luminal solutes, abates with fasting
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Causes of osmotic diarrhea?
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Lactulose Tx for hepatic encephalopathy/constipation
Rx'd gut lavage (go-lytely) Antacids (Magnesium salts) |
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What's your poo like in exudative diseases?
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purulent, bloody stools
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What's your poo like in malabsorption?
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voluminous, bulky stools with increased osmolarity and steatorrhea
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Causes of exudative diseases?
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Infectious (with destruction of epithelium) : Shigella, Salmonella, Campylobacter, Entamoeba histolytica
Inflammatory bowel disease |
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Causes of malabsorption?
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Infectious : Giardia lamblia
Defective aborption, due to mucosal abnorms, decreased surface area, lymphatic obstruction, etc |
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What's your poo like with deranged motility??
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Variable
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What types of things can decreased GI retention time?
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surgical shortening of gut, neural dysfunction including
***irritable bowel syndrome, hyperthyroidism, diabetic neuropathy, carcinoid syndrome***, et al. |
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What types of things can decreased GI motility?
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creation of surgical ‘blind loop’; bacterial overgrowth in small intestine
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What are the most common causes of Infectious enterocolitis?
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Rotavirus, Norwalk (Noro-) virus and E. coli most common agents in U.S., other industrialized nations
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Characteristics of rotavirus infections? (age group affected, mode of transmission?)
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affects children 6 - 24 months of age;
fecal-oral transmission |
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Prevalence of norwalk virus infections?
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responsible for most cases of non-bacterial foodborne illnesses
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What agents are implicated in bacterial Infectious enterocolitis?
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E.coli
Salmonella Shigella Clostridium difficile |
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What's important to know about some species of shagella? (typhi to be exact)
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They invade mucosa, cause sytemic illness (Typhoid fever)
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Where's Clostridium difficile found? When does it cause GI unhappiness?
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normal in gut, but may develop cytotoxin-producing strains after antibiotic use, resulting in pseudomembranous colitis
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What can cause problems with the digestion of fats and proteins?
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pancreatic insufficiency due to pancreatitis or cystic fibrosis
Zollinger-Ellison syndrome (inactivation of pancreatic enzymes by excess gastric acid) |
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What can cause problems with the digestion of fats? (specifically fat solubilization)
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defective bile secretion
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What can cause problems with the digestion/absorption in general?
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bacterial overgrowth
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Name 2 primary mucosal abnormalities that interfere with digestion/absorption?
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Defective digestion (lactose intolerance due to disaccharidase deficiency)
Defective transepith transport (abetalipoproteinemia) |
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Name 3 causes of small intestine reduced surface area that interfere with digestion/absorption?
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Gluten-sensitive enteropathy (celiac sprue)
Surgical resection Crohn’s Disease |
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Name 2 infections that interfere with digestion/absorption?
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Tropical sprue
Whipple’s disease (Troheryma whippelii) |
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What's the worldwide distribution of Crohn's Disease?
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highest incidence in U.S., northern Europe and Scandinavia, @ 1 - 3/100,000
rare in Asia and Africa |
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Age at which people develop Crohn's Disease?
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most common in 2nd and 3rd decades; second peak in 6th and 7th decades
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Clinical features of Crohn's Disease?
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Recurrent episodes of diarrhea, cramping abdominal pain, fever lasting days to weeks then disease remits for decades but recurs with increasing frequency. Assoc with systemic autoimmune. 50% have melena.
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Sequelae of Crohn's Disease?
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Fistula formation to surrounding organs and to skin
Abdominal abscesses or peritonitis Intestinal strictures/obstruction requiring surgical intervention Greatly increased risk for carcinoma of colon (5x - 6x) |
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Where in the GI do people develop Crohn's disease?
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Gross involvement of small intestine alone in 40%, small intestine and colon 30%, and colon alone in 30%.
May have involvement from mouth, thru esophagus, to stomach |
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Histologic features of Crohn's disease?
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“skip” lesions w/ intervening nl bowel
Thickened GI wall (transmural), serositis, and ‘creeping fat’ Noncaseating granulomas (40-60%) Fissuring w/ fisula tract format |
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When do people get ulcerative colitis?
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peak incidence 20 - 25 yrs
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Assoc between autoimmune and ulcerative colitis??
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associated with autoimmune diseases, especially migratory polyarthritis, more often than Crohn’s
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Where does ulcerative colitis occur?
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80% = rectum + rectosigmoid
10% involve whole colon Does not involve upper GI tract (Crohn’s does) |
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Relationship between ulcerative colitis and polyps?
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may exhibit ‘pseudopolyps’ which are regenerating mucosa, just as in Crohn’s involvement of colon
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Relationship between ulcerative colitis and malabsorption?
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not associated with fat/vitamin malabsorption as in Crohn’s
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Causes of mechanical bowel obstruction?
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herniation
adhesions (excess fibrous tissue which can strangulate bowel) intussusception (telescoping of segment of bowel upon itself) volvulus (twisting of loop of bowel upon itself) tumors |
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Causes of pseudo-obstruction?
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postoperative paralytic ileus
bowel infarction myopathies and neuropathies (e.g., Hirschsprung Disease) |
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Different shapes of polyps?
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pedunculated (with a stalk), or sessile (without a stalk)
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What makes polyps "true neoplasms"?
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If they result from epithelial proliferation
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When are polyps non-neoplastic?
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If they result from abnormal mucosal maturation, inflammation or architecture
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What percentage of polyps are non-neoplastic?
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90% of all polyps in the large intestine
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Types of non-neoplastic polyps?
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Hyperplastic (<5mm, NO malignant potential)
Juvenile (hamartomas in rectum in kids <5, NO malig potential) Peutz-Jeghers (auto dom, assoc with malig and intussesception) |
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How do true neoplastic polyps relate to colorectal carcinoma?
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associated with 4x risk for colorectal carcinoma
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What type of adenoma has the highest colorectal cancer risk?
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villous adenomas have a 40% malignancy association rate
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What's the colorectal cancer risk in a pt with familial polyposis?
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~ 100% by mid-life
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Which type of cancer accounts for 15% of all cancer deaths in the US?
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adenocarcinomas of the colorectum
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What age of pts develop colorectal adenocarcinoma?
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Peak incidence in 6th to 7th decades of life (fewer than 20% before age 50)
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Why's the incidence of colorectal cancer higher in developed countries?
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mainly dietary:
low content of fiber high content of refined carbs high fat content decreased intake vits A, C, E |
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How has the location of colorectal cancers in the US changed?
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25% are now seen in cecum or ascending colon
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Do colorectal cancers grow the same throughout?
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No - there's a difference between left and right growth patterns
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What's a good ddx rule for old anemic males?
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“iron deficiency anemia in an older male means gastrointestinal cancer until proven otherwise”
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How do you diagnose colorectal cancer?
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digital rectal exam
tests for occult blood Barium enema sigmoidoscopy, total colonoscopy with biopsy NOT CEA since is not specific (however, may be used to follow tumor and therapy) |
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What's the biggest influencer of colorectal cancer prognosis?
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extent of tumor at time of diagnosis
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Growth pattern and location for GI adenocarcinomas?
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grow in typical ‘napkin-ring’ configuration
arise in duodenum most commonly |
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What determines the malignant behavior of GI carcinoids?
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size, location and penetration:
appendiceal and rectal carcinoids rarely metastasize If > 2 cm in size 90% of ileal, gastric, and colonic carcinoids may have already spread |
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Take home message that can be applied to both GI carcinoids and male penises?
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Size matters.
(>2cm = bad bad news for both) |
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What's the most common location of a GI carcinoid?
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Appendix
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What's carcinoid syndrome?
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Caused by secretions from a carcinoid tumor
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What's the most common extranodal site for lymphomas?
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The GI tract
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Spread of primary GI lymphomas?
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NO splenic, nodal, liver, or bone marrow involvement at time of Dx
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Types of lymphocytes involved in GI lymphomas?
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typically are B cell lymphomas
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Prognosis for GI lymphomas?
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have a better prognosis than nodal lymphomas
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50-80% of acute appendicitis cases are assoc with what?
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Obstruction
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DDx for acute appendicitis?
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mesenteric lymphadenitis, PID, ectopic Pg, ruptured ovarian follicle, Meckel’s diverticulitis
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What tumors can you get in the appendix?
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Carcinoids
Mucocele: non-neoplastic obstruction of lumen, associated with fecalith, permitting slow accumulation of sterile fluid |
