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118 Cards in this Set
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Most common benign tumour of the small bowel
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leomyoma
adenoma lipoma |
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Most common malignant tumours of the small bowel?
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adenocarcinoma
carcinoid lymphoma leomyosarcoma |
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Are tumours of the small bowel common?
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<2% of malignant neoplasms pf GIT
often missed on screening |
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Epidemiology of small bowel carcinoma?
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More common in developed countries
lymphoma more common in caucasians No racial predeliction in adenocarcinoma Age 60-70 M= F menign > malignant, melignant more symptomatic |
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How do small bowel tumours present
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Pain: subacute vowel obstruction
Emergencies (50%): SBO (5%), bleeding (angiosarcoma, leomyosarcoma) |
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What is more sensitive than barium enema for tumours of the small bowel
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enteroclysis (involves a tube from the stomach into the duidenim which pumps barium in and allows for excellent visualsation of the small bowel mucosa)
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How do you make a diagnosis of small bowel cancer?
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Duodenal endoscopy and capsule endoscopy
enteroclysis is very sensitive (pumps barium through tube) CT with oral contrast ( extraluminal extent of nodal liver mets) |
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Diagnosis and management of leomyoma
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Most frequent in the jejunim: firm, grey-white lesion
Histologically: well developed smooth muscle cells without mitoses radiology: smooth filling defect with intact mucosa Enlarges intraluminally and may cause obstruction/untussuception Manage with surgical resection |
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Where are small bowel adenomas found?
How do these present? |
Duodenum esp peri ampullary
present: bleeding, duodenal/biliary obstruction |
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Aetiology and malignant potential of small bowel adenomas
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FEP associated
Same malignant potential of small bowel adenoma |
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Diagnosis and management of small bowel adenomas?
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Diagnose on gastroduodenoscopy with biopsy
Management: if small/benign: duodenotomy and small bowel submucosal excision If large: whipples procedure if in 34d/4th part of duodenum: segmental resection |
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What is the whipples procedure
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Removal of the distal half of the stomach (antrectomy), the gall bladder and its cystic duct (cholecystectomy), the common bile duct (choledochectomy), the head of the pancreas, duodenum, proximal jejunum, and regional lymph nodes. Reconstruction consists of attaching the pancreas to the jejunum (pancreaticojejunostomy) and attaching the hepatic duct to the jejunum (hepaticojejunostomy) and attaching the stomach to the jejunum (gastrojejunostomy).
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Where do bowel adenomas arise from?
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submucosal fat in the distal ileum
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Diagnosis and management of small bowel lipomas
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Arises from submucosal fat in the distal ileum
Diagnose by finding density on CT no malignant potential- excise if symptomatic |
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Where are small bowel adenocarcinomas usually found?
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periampullary in the duodenum
ileal in crohns 6th-7th decade |
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Disease associations with small bowel adenocarcinomas
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Crohns, FAP, celiac
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Where are small bowel adenocarcinomas usually found?
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periampullary in the duodenum
ileal in crohns 6th-7th decade |
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Imaging of small bowel adenocarcinomas?
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apple core defect with mucosal ulceration
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Disease associations with small bowel adenocarcinomas
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Crohns, FAP, celiac
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Management of small bowel adenocarcinomas
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pre-operative surgical staging
ERCP if preampullary: delineate biliary and pancreating involvement Surgery: wide segmental small bowel resection including draining mesenteric lymph nodes (not too many as may compromise viability of small bowel) LN mets --> poor outcome DISTAL ILEAL: right hemicolectomy with iliotransverse ansastomosis |
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Imaging of small bowel adenocarcinomas?
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apple core defect with mucosal ulceration
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Management of advanced small bowel adenocarcinoma with hepatic metastases?
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palliative small bowel resection to prevent bleeding snad small bowel obstruction
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Management of small bowel adenocarcinomas
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pre-operative surgical staging
ERCP if preampullary: delineate biliary and pancreating involvement Surgery: wide segmental small bowel resection including draining mesenteric lymph nodes (not too many as may compromise viability of small bowel) LN mets --> poor outcome DISTAL ILEAL: right hemicolectomy with iliotransverse ansastomosis |
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Management of advanced small bowel adenocarcinoma with hepatic metastases?
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palliative small bowel resection to prevent bleeding snad small bowel obstruction
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Management of locally advanced and unresectable small bowel adenocarcinoma?
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side to side enteroenteric by[pass
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Management of duodenal adenocarcinoma?
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Whipples procedure
LN metastases are not a contraindication to this |
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Prognosis of adenocarcinoma
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Overall poor prognosis
20% 5 year survival 60% of those with no nodal metastases |
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Where do gut carcinoids arise?
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85% appendiceal
2nd most common site is small bowel (distal ileal) 30% multi-centric |
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Malignant potential of gut carcinoids?
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Variable; appendiceal are mostly very benign and are often diagnosed incidentally whereas small bowel are more aggressive (and more likely to have symptoms such as anorexia/weight loss/carcinoid syndrome)
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Local effects of carcinoid tumours?
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cause an intense desmoplastic reaction in the mesentery due to local release of serotonin
Can lead to secondary mesenteric ischemia |
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Management of appendiceal carcinoids
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<2cm appendicectomy
>2cm appendicectomy and right hemicolectomy and resection of draininf nodes |
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Carcinoid tumours on imaging (of the small bowel)
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Barium: tethering of distal ileal loops- may not show tumour itself
CT: mesenteric nodal mets |
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Management of small bowel carcinoids
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segmental resection of small bbowel and en bloc mesenteric resection with primary anastomosis
careful infpection for syncronious mets (30%) |
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management of extensive disease in carcinoid tumours?
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palliative excision to debulk and delay onset of carcinoid syndrome + lymphadenectomy wo presvent desmoplastic reactop
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What are the precipitants of carcinoid syndrome?
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foods, alcohol, emotional stress
venous telangectasia, pellagra, right sided endocardial fibrosis CNS: dizziness, coma |
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Management of carcinoid syndrome?
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sandosatatin (somatostatin analogue)
30% of paitnets have a sustained response (2-5 years) chemotherapy: more effective if combined with hepatic artery embolisation |
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Prognosis of carcinoid tumours?
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generally slow growing
localised: like general population nodal mets + resection: 15 years non-resectable: intestinal 5yrs, liver 3 yrs |
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Features to suggest a small bowel lymphoma is "primary"
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mesenteric lymphadenopathy limited to small bowel
normal wcc no peripheral/mediastinal lymphadenopathy or splenomegaly |
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Modt common lymphomas in weatern countries
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1. Gastric lymphoma
2. Small bowel : ILEUM This is either an intermediate/high grade NHL (B-cell) or T-cell lymphoma which may be sporadic or associated with coeliac disease. |
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Associations of small bowel lymphoma
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crohns, coeliac, immunosuppression
15% multifocal usually occur in 5th decase |
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Symptoms of small bowel lymphoma
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Abdominal mass
25% obstruct/perforate/intussucept Malabsorption |
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Management of small bowel lymphoma
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resect bowel with wide margin of adjacent medentery + adjuvant adriamycin containing chemotherapy
If advanced: debulk and enteric bypass curative resection: 80% 5 year survival |
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What is the gender distribution of colon cancer?
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Rectal cancer is 2x more common in men
Right sided colon cancer is more common in females overall: 1/18 men, 1/28 women |
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By how much does your risk of colorectal cancer increase if you have affected relatives?
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2x if >55
6x if <55 or 2 ist degree |
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Iatrogenic/surgical factor that may lead to increased bowel cancer risk?
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RT to cervic: 10-20 year latency
uterosigmoidostomy cholecystectomy: increases risk of right sided colon cancer possibly from increased delivery of bile acids to the colon |
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Duke A, B , C?
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A: confined to bowel wall
B. Through serosa C: LN involvement: C1 apical node clear, C2 apical node involved |
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TNM staging of colorectal cancer:
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T1: submucosa
T2: muscularis propria T3: subserosa/pericolic T4: adjacent viscera/peritoneum No= no nodes n1: 1-2 pweicolic N2: 4 or more |
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Does left or right hand sided colorectal carcinoma carry a better prognosis?
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by stage right hand side has a more favourable prognosis then left hand side of the same stage
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Distribution of colon cancers?
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50% rectosigmoid junction/rectum
20% right sided |
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Prognosis of colorectal cancer
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85% of people with liver mets die within 1 year
Few develop mets beyond 5-10 years |
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What usually grows quicker; primary tumours or metastases?
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metastases usually grow more quickly
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How do iliocolonic fistulas due to malignancy present?
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severe diarrhoea
sigmoid cancer: may invade the bladder and form a colovecical fistula (recurrent UTI, hematuria, pneumaturia, fecaluria) |
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tYPES OF PAIN CAUSED BY ADVANCED RECTAL CANCER
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Perineal pain- anal sphincter involvement
sacral pain- invasion of sacrum and perineal nerve plexuses |
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Types of ascites seen in advanced rectal cancer?
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protein rich
chylous (from lymphatic obstruction) |
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What % of asymptomatic cancers will be positive on FOBT?
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80% in immunohistochemical tests
Also 70% of adenomas >1cm This is better than the guiac test that was 40-80% sensitive, more sensitive for LHS |
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What dietary restrictions did you have to impose for the old guiac FOBT's?
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Avoid red mear, horseradish, vit C, NSAIDS for 3 days
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Which patients with colorectal cancer get CT screening for metastases?
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Does not significantly after outcome so reserve for patients in whom distant metastases are suspected and in the elderly where a less radical approach may be justified.
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tYPES OF PAIN CAUSED BY ADVANCED RECTAL CANCER
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Perineal pain- anal sphincter involvement
sacral pain- invasion of sacrum and perineal nerve plexuses |
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Types of ascites seen in advanced rectal cancer?
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protein rich
chylous (from lymphatic obstruction) |
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What % of asymptomatic cancers will be positive on FOBT?
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80% in immunohistochemical tests
Also 70% of adenomas >1cm This is better than the guiac test that was 40-80% sensitive, more sensitive for LHS |
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What dietary restrictions did you have to impose for the old guiac FOBT's?
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Avoid red mear, horseradish, vit C, NSAIDS for 3 days
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Which patients with colorectal cancer get CT screening for metastases?
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Does not significantly after outcome so reserve for patients in whom distant metastases are suspected and in the elderly where a less radical approach may be justified.
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Does CEA monitoring alter mortality after colorectal cancer resection
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nor according to chandra
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How much colon is usually resected in rectal versus colon cancer
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colon: 10-15cm with lymphovascular clearance
recrum: less, 5cm margin is preferred but as little as 2cm can be taken for a small, mid rectal cancer: do a wide lateral resection including the mesorectum |
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Are laparoscopic outcomes worse than open ones for bowel cancer resection?
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equivalent in the hands of experienced surgeon
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Bowel prep for colorectal cancer resection in the setting of a partial bowel obstruction?
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gentle, over 2-3 days
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Bowel prep for colorectal cancer resection in the setting of a complete bowel obstruction?
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Intra-operative anterograde lavage of colon using foley catheter through appendix stump/distal ileum is a primary anastomosis is desired
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Antibiotic prophylaxis for colon cancer resection?
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24 hours post-op
do not continue for longer due to risk of pseudomembranous colitis |
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Appropriate antibiotic prophylaxis for colorectal surgery (colorectal surgery, appendicectomy, upper GI or biliary surgery)
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metronidazole + xephazolin/gent
or cefoxitin |
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management of carcinoma of caecum/ascending colon
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Right hemicolectomy with removal of ileocolic, right colic and right branches of midcolic
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Management of carcinoma of the transcerse colon
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if right: right hemicolectomy
mid transverse colon: extended right hemicolectomy- anastomose between terminal ileum and descending colon splenic flexute: subtotal colectomy- anastomose between terminal ileum and sigmoid colon |
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Why is a subtotal colectomy done for cancer of the splenic flexure?
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can spread via the midcolic as well as the left colic lymphatics due to dual blood supply
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management of cancer of the descending colon
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left hemicolectomy
take IMA at origin and anastomose mid transverse colon and upper rectum |
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Management of sigmoid cancer
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high anterior resection: anastomose the mid descending colon to the upper rectum
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Appropriate antibiotic prophylaxis for colorectal surgery (colorectal surgery, appendicectomy, upper GI or biliary surgery)
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metronidazole + xephazolin/gent
or cefoxitin |
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What precludes the use of sphincter preservation procedures in the management of rectal cancer?
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pre-operative sphincter impairment
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Which rectal cancers are eligible for am low anterior resection
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Tumours of the upper-mid rectum
Small tumours of the distal rectum where a 2cm margin is possible without damaging sphincters |
Low anterior resection involves dissection and anastomosis below the peritoneal reflection with ligation of the superior and middle haemorrhoidal arteries
Ultra-low: complete mobilisation of the rectum down to the pelvic floor + dissection of plane between pelvic floor and vagina in a woman and prostate in men. |
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What are the steps of an anterior resection?
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1. Resect sigmoid colon and rectum
2. IMA and L. colic are divided high: to enable tension-free anastomosis between the well vascularised left colon and rectum 3. remove mesorectum beyond the distal line of the rectal resection |
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What defines a high versus a low anterior resection?
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Defined by whether colorectal anastomosis is intraperitoneal or extraperitoneal
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What determines functional results after anterior resection
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vary with level of anastomosis- bowel function improves for 12-18 months post-operatively
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Properties of very distal anastomosis after a low anterior resection?
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If very distal: lose rectal reservior and sphincter function
3-6 stools in 24 hours Urgency and impaired continence |
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Frequency of anastomotic leaks after anterior resections?
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high 1%
low 4% Defunctioning stoma may reduce incidence of generallised sepsis should an anastomotic leak occur |
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Indications for an abdominoperineal resection for rectal cancer?
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T2, T3 or poorly differentiated tumours of the distal rectum
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What is involved in an abdominoperineal resection?
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1. rectum mobilised down to the pelvic flood via an abdominal incision
2. Large bowel is divided and the sigmoid is brought out to LIF as an end colostomy 3. Perianal ellyptical incision to mobilise and deliver the anus and distal rectum (2 surgeons can simultaneously do these steps) |
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Indications for transanal local excision of rectal cancer
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Early stage rectal cancers that are too distal to allow restorative resection or when age/infirmity/mets preclude major resection
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In which cases is a transanal lower resection curative>?
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mobile, lower 1/2
<3cm T1 or T2 Well/moderately differentiated on histo or biopsy No detectable mesorectal LN clinically or by ultrasound |
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Adjuvant therapy for duke C colon cancer:
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6m 5FU + folinic acid
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Indications for adjuvant therapy in rectal cancer
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Duke C/ B2
6m 5FU + pelvic RT |
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In what situation is neoadjuvant chemoradiotherapy used
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preoperatively to downstage T3/4 rectal cancers that are fixed to the pelvis. Resect 6-8 weeks later
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When does routine follow-up for a patient who has previously had bowel cancer cease?
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Age 75
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Management if small/large colorectal adenomas
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Small: biopsy then cautery
large: snare very large: snared in pieces low rectal: transanal disc excision |
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Follow-up if 1 polyp found on colonoscopy
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in 3 years
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Colon cancer screening guidelines for those at or above average risk
(includes 1 first degree rel if 55 or older) |
FOBT every 2 yrs starting feom 50
consider flex sig every 5 years starting from age 50 |
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Guidelines for screening those ad morerately increased risk of colorectal cancer (1-2% of pop): 1 1st <55, 2 1st or 2nd on same side of the samily with CRC at any age
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cOLONOSCOPY EVERY 5 YEARS STARTING AT 50 OR AT AN AGE 10 YEARS YOUNGER THAN AFFECTED REL
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Define those people (<1% of the population) that are potentially at high risk of CRC
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3 or more 1st or 2nd degree relatives on the same side of the family (suspected HNPCC)
2 or more with colorectal cancer: including high risk features: multiple, <50, one with endometrial/ovarian (suspected HNPCC) or 1 rel with multiple adenomas (FAP) or Somebody in family with MMR or FAP gene mutation |
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Follow-up of patients with 1-2 cmall, tubular adenomas
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5 years- if normal then 10 yearly colonoscopy/FOBT every 2 years
There is no conclusive evidence that one or two small tubular adenomas constitute more than average risk for metachnronous advanced adenomas or cancer |
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Define high risk adenomas on colonoscopy
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three or more adenomas
adenomas >1cm tubulovilloous or villous histology high grade dysplasia |
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Follow-up for patients with high risk adenomas
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surveillance colonoscopies at three yearly intervals
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follow-up after removal of sessile adenoma
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3-6m - to make sure all removed
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When should colonoscopy be done following resection of a rectal cancer?
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one year after - if normal then do another one in 5 years, if high risk adenomas do another one in 3 years
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Colonoscopic screening of individuals with inflammatory bowel disease?
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2-3 yearly after 8 years
take multiple random biopsies (risk is not increased if disease is limited to distal proctosigmoiditis) |
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What % of FAP arises from new mutations?
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25% have spontaneous new mutations
Fap accounts for 0.5% of CRC |
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Where is the APC gene mutation found?
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5q21
Diagnose by linkage analysis (microsatellites near APC gene) or by testing the APC gene itself |
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Extracolonic manifestations of FAP
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Osteomas (Gardeners): especially in skull and mandible
Desmoid tumours (10%) Gastrofucodenal polups |
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Prognosis of desmoid tumours in FAP?
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do not metastasize but have aggressive local growth
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Management of desmoid tumours in FAP
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sulindac (NSAID) + tamoxifen
surgery can be very complicated chemo is last resort Now that death from colorectal cancer is less common in people with FAP- death from mesenteric strangulation by a desmoid has become more common |
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Types of gastroduodenal polyps in FEP
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gastric hamartomas
duodenal adenomas- the ones around the ampulla of vater are especially likely to develop into cancer |
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Screening for upper GI cancer in FAP
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Upper GI endoscopy age 20-25
If large number of polyps: annual Otherwise every 5 years, more frequently > age 45 |
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Why do people with FAP get retinal pigmentation?
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congenital hypertophy of the retinal pigment epithelium
Interestingly this has an inverse relationship with desmoid tumours |
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Management of FAP
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colectomy once adenomas develop- then remove retained rectum after 40
Can also do a restorative procolectomy to eliminate risk of rectal cancer or total procolectomy with end iliostomy in patients presenting with low risk rectal cancer |
Gene carriers or family members who have not genetic testing get yearly colonoscopy/flex sig (as most polyps rectosigmoid)
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Inheritance of HNPCC
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Autosomal dominant: 80% penetrance f cancer. 60% endometrial cancer in women with HNPCC.
Cancer onset at 44 years on average, 70% in proximal colon Increased sunchronous or metachronous lesions (approximately 45% 10 years after primary resection) |
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What non-colon cancers are found in excess in HNPCC
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endometrial carcinoma
TCC of ureter and kidney Adenocarcinomas of the stomach, small bowel, ovary, pancreas and biliary tract |
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Is polyposis a feature of HNPCC?
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no, incidence of adenomas is similar to general pop
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Screening in a person whose family Hx suggests HNPCC
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Colonoscopy at age 25 then 2 yearly to 35 then annually
If have gene mutation confirmed: colonoscopy started at age 20 then repeated annually |
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Management of confirmed HNPCC
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offer prophylactic colectomy
once cancer found- abdominal colectomy with iliorectal anastomosis Screening with endometrial aspiration biopsy, ovarian ultrasound (TVUS) and CA125 |
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Incidence of dysplasia after long-term ulcerative pancolitis
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5-10%
MUCH INCREASED RISK OF CANCER ESPECIALLY WHEN THERE IS A LESION SUCH AS A POLYP OR A STRICTURE |
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Where is the bowel cancer related to ulcerative colitis more likely to occur?
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int he right/transverse colon
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Indications for colectomy (to prevent cancer) in IBD
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any dysplasia in a polyp
dysplasia in 2 or more flat areas that is high grade |
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