Adenocarcinoma in the anal transitional zone after ileal pouch for ulcerative colitis: report of a case.

This article reports the seventh known case of adenocarcinoma arising in or adjacent to an ileal pouch after proctocolectomy for ulcerative colitis. It is the second reported case of adenocarcinoma in the anal transitional zone in this setting. A literature review is presented of the six previous cases published, and on the wider subject of how to best manage the anal transitional zone. It is concluded that this is a rare, but catastrophic, event with a potentially poor prognosis and can occur late (more than a decade) after the original surgery. All ileal pouches performed for ulcerative colitis should be followed for extended periods. The development of dysplasia necessitates close follow-up, including regular biopsies, and local excision and pouch advancement can manage persistent dysplasia. When operating for dysplasia or cancer, biopsies of the anal transitional zone should be performed or consideration given to mandatory mucosectomy.