INFO/WWW-LINKS: Colorectal carcinomas are adenocarcinomas which may often arise in pre-existing polyps. About 40% of these carcinomas are located in the rectum, 20-30% in the sigmoid colon, and about 30% in the descending, the transverse and coecum with ascending colon. Colorectal carcinomas spread local, lymphatic and haematogenous - especially - to the liver and the lung.