Carcinosarcoma of the prostate in combination with adenocarcinoma of the prostate and adenocarcinoma of the seminal vesicles. A case report with immunocytochemical analysis and review of the literature.

A unique triad of a carcinosarcoma and an adenocarcinoma of the prostate as well as an adenocarcinoma of the seminal vesicles in a 67-year-old man is reported. The carcinosarcoma was investigated by immunohistochemical methods. The mesenchymal parts of the sarcoma showed chondromatous differentiation expressed by S-100 protein and vimentin. The undifferentiated epithelial elements of the carcinosarcoma reacted positively to the panepithelial antibody lu-5 and to carcinoembryonic antigen (CEA). The adenocarcinoma of the prostate stained with antibodies to panepithelial antigen (lu-5), prostatic acid phosphatase, prostate specific antigen and CEA, whereas the adenocarcinoma of the seminal vesicles reacted only to lu-5 and CEA. The literature is reviewed.