Diffuse colitis cystica profunda. Report of a case.

A 20-year-old man had a 2-year history of ulcerative colitis with multiple exacerbations and failure of medical management. In addition to evidence of ulcerative colitis involving the descending colon and rectum, the remainder of the total proctocolectomy specimen demonstrated prominent, circumferential, polypoid elevations of mucosa and epithelial-lined, submucosal mucous cysts diagnostic of colitis cystica profunda. The involvement of the ascending and transverse colon was diffuse. Colitis cystica profunda is an uncommon condition, usually localized to the rectum and which can be misdiagnosed both clinically and pathologically as invasive carcinoma. Diffuse involvement of the proximal colon as noted in this case, is exceedingly rare.