Villous adenoma of the urinary bladder: a case report.

Villous adenomas of the urinary tract are rare, in contrast to urothelial neoplasms. Most reports were scattered individual cases. Only two case series of this entity have been published. The histopathology is identical to that of the much more common villous adenoma of the gastrointestinal tract. The authors reported a case of urinary bladder villous adenoma in a 41-year-old Thai patient who complained of hematuria for one day without any other symptom. Cystoscopic examination revealed a papillary growth at the bladder neck associated with marked degree of bullous edema and bilateral mild hydroureters. The clinical diagnosis was urothelial carcinoma. Transurethral resection was performed Histologic examination revealed typical features of villous adenoma. The tumor showed identical immunohistochemical profile to colonic villous adenoma. The patient has been well for more than a year after tumor removal.