a colorectal polyp is a small clump of epithelial cells that form a small bump or overgrowth of tissue along the lining of the colon or rectum the cells lining the colon and rectum are constantly dividing and typically when there's an overgrowth of tissue it's benign but some can become malignant meaning that the dividing cells can start invading nearby tissues over time now there are various types of colorectal polyps the most common ones are adenomatous polyps also called colonic adenomas and these form when there's a mutation in the adenomatous polyposis coli gene or apc gene which is a tumor suppressor gene that regulates cell growth when the apc gene is mutated the epithelial cells start to quickly divide which forms polyps sign up for a free trial today and watch the full video on osmosis.org [Music] bye