Anal duct carcinoma: case report and review of the literature

This report details the clinical course of two patients with true anal duct carcinoma. The incidence of this malignancy is low. The tissues of origination are the glands of the anal duct. The features that differentiate this tumor from the usual rectal carcinoma are prominent ductal structures, abundant mucin production with organized mucinous pools, and infiltration into the perirectal soft tissue. The clinical management of anal duct carcinoma remains a surgical challenge. The extent of surgical resection must be radical because of the infiltrative nature of the tumor. This report describes treatment of two patients with anal duct carcinoma. The first patient was a black woman with no previous history of rectal disease. Her operative procedure was an abdominoperineal resection with posterior vaginectomy. Nine months after initial surgery a local recurrence was resected. The second patient was a white man with a previous history of hemorrhoidectomy and anal fissure. He underwent an abdominoperineal resection but had positive dermal skin margins on permanent sections despite wide perirectal soft tissue resection. A secondary resection with confirmed clear margins of the skin was performed 2 weeks postoperatively. One management aspect of anal duct carcinoma that needs emphasis is the need for wide local excision of the perirectal soft tissues.