Anal cloacogenic carcinoma: classification and clinical behavior.

A retrospective study of 35 patients with anal cloacogenic carcinomas showed that the histological characteristics of the tumors were correlated with their biological behavior. The basaloid squamous type of cloacogenic carcinoma was more common in women (3.6:1) and had a more favorable course in both men and women, with a mean survival of 5.0 years. Glandular variants of these tumors, with an adenocystic or mucoepidermoid pattern, occurred predominantly in men and had a more aggressive course, manifested by early metastases to inguinal and mesenteric lymph nodes, liver, and lung, with mean survival limited to 2.5 years. Nine of the 11 patients who survived longer than five years had the basaloid squamous histological pattern and were treated by abdominoperineal resection or pelvic exenteration; five of these patients also received postoperative therapy with radiation. The overall actual five-year survival for patients with anal cloacogenic carcinoma was 41% in this study. The histological pattern of anal cloacogenic carcinoma provides useful prognostic information to the clinician.