OBJECTIVE: We report on 11 cases of inverted urothelial papilloma and discuss the management and significance of this rare benign urothelial lesion.MATERIALS AND METHODS: From 1990 to 2002, eleven patients were pathologically documented as having inverted urothelial papilloma in our institute. Their demographic data, presenting symptoms, diagnoses, and treatments were retrospectively reviewed.RESULTS: Of the 11 patients, 2 were women (18%). The mean age at presentation was 62 years. The tumor was located in the bladder neck (6 cases), trigone (2 cases), posterior and lateral wall (2 cases), and lower ureter (1 case). No patient had multiple lesions. The most common presentations were hematuria and obstructive complaints. A filling defect was noted in only 1 of 3
patients who had excretory urograms, and a discrete heterogeneous mass was seen in 2 (50%) of 4 patients who received transrectal ultrasonography. Diagnosis required direct visualization and
biopsy. Lesions in the bladder were all resected transurethrally. One patient with a lesion in the lower ureter was treated by segmental ureteral resection. Most lesions (7 of 11) were macroscopically described as polypoid lesions, with a diameter of 2 to 23 mm. No patient had recurrence or subsequent development of urothelial carcinoma after a mean follow-up of 51 (range, 1-144)months.CONCLUSIONS: Inverted urothelial papillomas are rare benign lesions with a male predominance.A definite preoperative diagnosis is difficult. For tumors in the upper tract, pathologic diagnosis based on endoscopic biopsy or intraoperative frozen section may obviate the need for radical surgery.