[Small cell carcinoma of the prostate: a case report].

An 80-year-old man visited our hospital because of dysuria and pollakisuria. He had undergone anti-androgen therapy for prostate cancer for 8 months at another hospital. His serum prostate specific antigen (PSA) level was 14.4 ng/ml. We performed a prostate biopsy and identified poorly differentiated adenocarcinoma with Gleason score 4 + 5. After 4 months, his serum PSA level increased to 24.8 ng/ml, and we started maximum androgen blockade therapy using additional luteinizing hormone-releasing hormone (LH-RH) analogue. Subsequently, although his serum PSA level declined favorably, his condition worsened rapidly and he died at 16 months after the diagnosis. The autopsy pathology of his prostate revealed small cell carcinoma. We reviewed the initial biopsy specimens and found both small cell carcinoma and adenocarcinoma histologic types of prostate cancer.