[Small cell carcinoma of the prostate: a case report--a prognostic analysis of case reports and literature in Japan].

A 62-year-old Japanese man had been suffering from dysuria since January 2011. Since symptoms persisted regardless of antibiotics therapy at a urological clinic, he consulted our clinic in February 2011. Digital rectal examination revealed a large irregular and stony hard prostatic mass, with the serum prostated specific antigen (PSA) of 2.76 ng/ml. T2-weighted magnetic reasonance imaging showed diffuse hypointensity and sharp margin in prostatic peripheral zone. Transperineal biopsy of the prostate was performed in March 2011. Considering histopathological findings of tumor cells in all specimens combined with positive immunoreactivity of neoplastic cells to chromogranin A but negative immunoreactivity to PSA, we diagnosed him with small cell carcinoma. The whole body computed tomography showed no metastatic lesion, he was diagnosed with small cell carcinoma of the prostate at clinical stage T2cN0M0. He received 4 cycles of chemotherapy (cisplatinum and etoposide) and underwent external beam radiotherapy to the pelvis and prostate, up to a total dose of 64 Gy. The urologic and radiologic outcomes including the serum levels of neuron-specific enolase and pro-gastrin releasing peptide have been satisfactory after more than 3 years of follow-up.