Pseudosarcomatous carcinoma of the anal canal

A polypoid pseudosarcoma of the anal canal in a 45-year-old woman was surgically treated. Morphologic characteristics of the tumor were essentially identical with those in hitherto-described pseudosarcomas of the esophagus, larynx, fauces, or oral cavity. Histologic features of the tumor support the presumption of epithelial origin of the sarcoma-like element on the basis of the presence of a clearly epithelial element in the sarcoma-like areas, justifying the term "pseudosarcomatous carcinoma," instead of "pseudosarcoma." This is the first report of this tumor type detected in the anal canal.