On rectal examination, a patient is found to have a large, fungating mass protruding into the rectal lumen. Biopsy of this mass demonstrates an invasive malignant tumor composed of glandular structures. The development of this condition is most strongly associated with

The disease is adenocarcinoma of the colon. Predisposing conditions include inflammatory bowel disease (ulcerative colitis more than Crohn's disease) and adenomatous polyps occurring either as an isolated finding or as pa of familial syndromes including familial polyposis coli, Gardner syndrome, and Turcot syndrome. Western diets high in fat and protein and low in fiber are also thought to predispose for colon cancer. Diveiculitis (inflamed diveicula) and diveiculosis (presence of diveicula in colon) do not appear to predispose for colon cancer. Neither juvenile polyposis syndrome , in which the polyps consist of mucus-filled tubules, nor Peutz-Jeghers syndrome , in which polyps form around an arborizing tree of connective tissue and smooth muscle, predisposes for colon cancer. Ref: Wyatt C., Butterwoh IV J.F., Moos P.J., Mackey D.C., Brown T.G. (2008). Chapter 14. Gastrointestinal Pathology. In C. Wyatt, J.F. Butterwoh IV, P.J. Moos, D.C. Mackey, T.G. Brown (Eds), Pathology: The Big Picture.