Polyps of the Colon and Rectum Flashcards
What is a GI polyp?
A mass that protrudes into the lumen of the gut
What are adenomatous polyps?
(Tubular adenomas) Neoplasms that arise from colonic epithelium that are potentially premalignant
Where are approx 50% of all adenomatous polyps of the colon in the colon located?
In the rectosigmoid region
What characteristic of a tubular adenoma would allow for it to be easily cured by resection?
Dysplastic focus remains confined to the mucosa
Which has foci of carcinoma more often? Villous or tubular adenomas?
Villous!
What is the precursor to colorectal carcinoma?
Dysplasia typically in the form of an adenoma
Relationship b/w adenomatous polyps and colorectal cancer?
- Geographical coincidence
- Carcinomas are found in adenomas
- Prophylactic polypectomies have significantly reduced the risk of later cancer
Small sessile mucosal protrusions with exaggerated crypt architecture?
Hyperplastic polyps
Difference between classic hyperplastic polyps and and hyperplastic polyps (serrated adenomas)?
Serrated adenomas have an increased risk of developing adenocarcinoma
What is the autosomal dominant trait that invariably leads to cancer?
Familial Adenomatous Polyposis
Genetic mutation that is responsible for adenomatous polyposis coli?
Mutation of the APC gene on chromosome 5
What is the outlook for a person with familial adenomatous polyposis?
Cancer is inevitable
Benign acquired hamartomatous proliferations of the colonic mucosa found in chidlren <10 yo?
Juvenile Polyps (Retention polyps)
What do retention polyps retain?
They are filled with mucus
What mutation occurs in patients with familial juvenile polyps?
SMAD4 mutation
