[Clinical studies of inverted papilloma of the bladder].

Inverted papilloma of the bladder is an uncommon urothelial neoplasm. Although it is traditionally regarded as a benign tumor, there are conflicting data on multiplicity, reoccurrence rate, and association with urothelial carcinoma. From 2005 to 2011, 14 cases of inverted papilloma of the bladder were diagnosed at our hospital. Clinical features of 14 cases were summarized. These patients ranged in age from 25 to 81 years (mean, 61 years). The most frequently occurring symptom was gross hematuria. Eleven bladder tumors arose from the trigone or near the bladder neck. One case was associated with urothelial carcinoma. One was suspected to be a case of tumor recurrence. All other patients were free of tumor recurrence during the mean follow-up of 16.4 months (range, 0-75 months). This study does not suggest the malignant potential of inverted papilloma. However, since inverted papilloma may correlate with urothelial carcinoma. Post-treatment follow up for inverted papilloma should include cystoscopic follow up.