Carcinosarcoma of the urinary bladder. Report of a case with electron microscopy and review of the literature.

A case of carcinosarcoma of the urinary bladder in a 33-year-old man is presented. The tumor developed from the left anterolateral wall and protruded into the vesical lumen. The excised tumor revealed that more than 99% was sarcomatous component with the appearance of an osteochondrosarcoma. Small foci of papillo-tubular carcinoma were scattered in the sarcomatous area. The histological features, histogenesis and treatment of carcinosarcoma of the bladder are discussed in relation to the literature.