Lower GI pathology Flashcards
Down’s syndrome
Double bubble sign
Duodenal atresia
Distal bowel
Tubular structures attached to intestines sharing common blood supply
Mesenteric side
Can cause obstruction
Intestinal duplication
Causes of chronic colitis
CD, UC, TB
EM + PG
IBD
EM + PG + EN + Aphthous ulcers
CD
Post-Abx
Macroscopic wet cornflakes appearance
Microscopic volcano explosion
Pseudomembranous colitis (C difficile protein exotoxins cause acute colitis post-Abx)
Pseudomembranous colitis Tx
Treat with metronidazole 14d course, if persists vancomycin
Causes of non-neoplastic lower GI polyps
Hyperplastic
Inflammatory pseudo-polyp
Peutz-Jeughers
Adenoma
Epithelial proliferation + dysplasia
Tubular, villous or tubulovillous
20-30% <40, 40-50% >60
Adenoma > Adenocarcinoma progression (invasion of BM)
RF for adenocarcinoma: >4cm, increased villous component, increased dysplasia
FAP = loads of adenomas (mutation of APC TS gene - 5q21)
Lots of adenomas
APC TS gene mutation 5q21
100% get adenocarcinoma
FAP
Risk factors for adenoma > adenocarcinoma
> 4cm
Villous
Increased dysplasia
Adenocarcinoma
98% of colorectal cancer
60-79 (<50 consider familial syndrome)
Diet, lack of exercise, obesity, familial, IBD
May be from adenoma pathway or due to IBD / HNPCC)
Duke’s staging
Duke’s staging
For adenocarcinoma A - limited to mucosa B - wall C - lymph node mets D - distant mets
Uncommon AD disease - 3-5% of colorectal cancer
RER mismatch reprair gene mutation
Multiple tumours proximal to splenic flexure
Mucinous
Other extra-colonic cancer (endometrium, prostate, breast, stomach, ovarian)
HNPCC
Young person with colorectal cancer
Think familial neoplastic intestinal disease - FAP, Gardner’s, HNPCC, PJS (mostly AD - think ‘ADenoma’)
