[Small cell carcinoma in a vesical diverticulum: a case report].

We report a case of small cell carcinoma located within the vesical diverticulum. A 73-year-old woman referred to our hospital with a chief complaint of gross hematuria. Cystoscopy confirmed a non-papillary tumor within the vesical diverticulum. Histopathologic diagnosis with transurethral resection of the tumor (TURBT) specimen was small cell carcinoma. Later, tumor recurrence occurred within the same diverticulum. TURBT and biopsy of the vesical mucosa were performed. After confirming that no tumor was detected outside of the diverticulum, partial cystectomy was done including an adequate margin around the diverticulum in September, 2010. Since the histopathologic finding of the specimen revealed urothelial carcinoma (UC) this time and microinvasion and venous invasion were detected, we performed an adjuvant chemotherapy according to the protocol of gemcitabine and cisplatin therapy. To our knowledge, this is the 4th case report of small cell carcinoma located in a vesical diverticulum in Japan.