Adenomatous polyps are growths that form on the lining of the colon or rectum. They are considered precursors to colorectal cancer because they can develop into cancer over time if not removed. These polyps are usually benign, meaning they are not cancerous, but their presence can indicate an increased risk for cancer. There are different types of adenomatous polyps, including tubular, tubulovillous, and villous adenomas. The risk of cancer increases with the size and type of the polyp. Regular screening, such as colonoscopy, is important for early detection and removal of these polyps to prevent the development of cancer.