Carcinosarcoma (mixed mesodermal tumor) of the ureter.

An unusual tumor of the ureter in an elderly man is reported. The tumor showed evidence of epithelial and mesenchymal differentiation based on histological and immunocytochemical criteria, and it behaved aggressively, comparable to that seen in other mixed tumors of this type arising from elsewhere within the genitourinary tract. It is proposed that this tumor be designated carcinosarcoma of the ureter.