The adenomatous polyp and the hereditary polyposis syndromes.

Adenomatous polyps are the benign precursors of colorectal adenocarcinoma. Colonic adenomas occur commonly in adults in Western countries. There is recent evidence that inheritance may play an important role in the etiology of these adenomatous polyps. Colonic adenomatous polyposis (numerous colonic adenomas) is the central feature of several rare inherited syndromes that give rise to colorectal cancer. There also appears to be a risk of gastrointestinal and other malignancies in the rare inherited syndromes of hamartomatous polyposis.