[Inverted papilloma of urinary bladder in two patients with urination difficulty as initial symptom].

We report two men with inverted papilloma of urinary bladder with urination difficulty as initial symptom. One was 51 years old and the other was 60 years old. Ultrasound revealed a tumor in the bladder and cystoscopy revealed a smooth-surfaced tumor with a stalk at the bladder trigon. They underwent transurethral resection of the bladder tumor and histopathological findings were consistent with inverted papilloma. Postoperatively, they are free of urination difficulty and have had no recurrence for 3 and 1 years, respectively.