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 111-5 and CEA. The literature is reviewed, Cancer 66:998-1001,1990.
ARCINOSARCOMA OF THE PROSTATE is an extremely C rare tumor. To our knowledge only eight well-documented cases are reported in the literature. Although carcinoma of the prostate is a common tumor in elderly men, sarcoma of the prostate arises in younger patients.' The rarity of sarcomas, and the difference in age at which carcinomas and sarcomas develop, make it very unusual that sarcomas and carcinomas coexist in the same patient.2-4 Carcinosarcomas appear to be distinct entities, considering clinical course, prognosis, and the rap^.^
Case Report
A 67-year-old man was admitted to the Basel University Hospital, Basel, Switzerland, in May 1985 because of painful defecation and obstipation. Rectal digital examination revealed an induration, irregularity and nodularity of the prostate. Cystoscopic examination revealed no abnormalities. Histopathologic diagnosis of a fine-needle biopsy was undifferentiated sarcoma. A computed tomography (CT) scan of the pelvis showed a large From the *Department of Pathology and the tUrologica1 Clinic, De-