[Neuroendocrine differentiation in adenocarcinoma of the prostate during hormonal treatment : a case report].

A case of neuroendocrine (NE) differentiated prostate cancer is reported herein, which was progressed with NE differentiation during hormonal treatment in adenocarcinoma of the prostate. A 65-year-old man was admitted to our department with increased serum prostate specific antigen (PSA) (150 ng/ml). A prostate biopsy was performed and histological examinations indicated poorly differentiated adenocarcinoma with a Gleason score of 5 + 4 = 9. Further examinations showed metastases to systemic bones. The clinical stage was T3bN0M1b and hormonal therapy using leuprorelin was started. Eighteen months after hormonal therapy, the serum PSA level declined to 1.702 ng/ml. He subsequently experienced edema in his legs. Computed tomography (CT) demonstrated enlargement of the prostate and swelling of multiple pelvic lymph nodes. Immunohistochemical examination of a re-biopsy specimen revealed a neuroendocrine carcinoma. The neuron-specific enolase (NSE) level was 50.9 ng/ml. The treatment measure was changed from hormonal therapy to combination chemotherapy comprising cisplatin (CDDP) and irinotecan (CPT-11). Pelvic radiotherapy (50 Gy) was then performed. Two courses of the chemotherapy resulted in a great reduction of the tumor volume. However, he had liver metastases 3 months later. His condition worsened rapidly and he died at 8 months after definite diagnosis.