[A case of small cell carcinoma in the urinary bladder responding to gemcitabine/cisplatin combination therapy as neoadjuvant chemotherapy].

We report a case of primary small cell carcinoma of the urinary bladder. A 79-year-old man with the chief complaints of macrohematuria and pollakisuria was admitted to our hospital. Cystoscopy and computed tomography (CT) revealed a non-papillary broad-based bladder tumor. Histological diagnosis was small cell carcinoma of the urinary bladder, and he underwent 3 courses of neoadjuvant chemotherapy including gemcitabine and cisplatin with a preoperative diagnosis of cT3bN0M0. After the chemotherapy, cystoscopy and CT showed complete remission. Total cystectomy with ileal conduit was performed following 3 courses of chemotherapy. Microscopic examination revealed that the small cell carcinoma had disappeared and the converted squamous cell carcinoma remained only in a small part of the specimens. The patient was carefully followed for 10 months after operation, with no tumor recurrence.