Cloacogenic tumors of the anorectal junction.

The cloacogenic zone of the anal canal is a vestigial remnant of the cloacal membrane. This region corresponds to the columnae anales and anal glands. The epithelial lining of the anal glands and of the cloacogenic zone is of the transitional variety. The anal glands are well known to the surgeon because of their role in the pathogenesis of perianal abscesses and fistula in ano. Tumors arising from the cloacogenic zone of the anal canal are rare. In most instants these carcinomas have characteristic clinicopathological features. These lesions are named transitional cloacogenic carcinoma. The therapy of choice is an abdominal-perineal rectum amputation with wide excision of the perineal soft tissue. Inguinal node dissection is indicated if the nodes appear clinically involved. No conclusions have been reached to determine the radiosensitivity of cloacogenic carcinomas. Five cases of cloacogenic carcinoma are reported and the clinicopathological and therapeutic aspects discussed.