[Small renal cell carcinoma of the prostate with cerebral metastasis]

Presentation of one case of non-differentiated small cell prostate carcinoma, not associated to adenocarcinoma, in a male patient diagnosed with Benign Prostate Hyperplasia and Lymphoproliferative Syndrome, seen at the clinic due to worsening of mictional symptomatology. The diagnosis of non-differentiated carcinoma was reached through transrectal biopsy of a prostate node. Initial staging after diagnosis was T4a, N2, M1c (TNM, 1992), as liver and brain metastasis were already present. No bone or lung involvement was found. Specific Prostate Antigen value was 7.4 ng/ml, Carcino-Embryonary Antigen (CAE) was normal and ACTH slightly elevated. Differential diagnosis was primarily established with lymphoma. Using immunohistochemical techniques, the tumoral cells were positive for low molecular weight Keratin (CAM 5.2) and specific neuronal Enolase; negative for specific prostate antigen, prostate acid phosphatase, common leucocyte antigen and ACTH. The initial treatment consisted in one course of carboplatin plus VP-16 chemotherapy. The patient died six months after diagnosis.