Urothelial Inverted Papilloma of the Lower Urinary Tract—A Benign Lesion or a Precursor of Malignancy?

Abstract

Objective We investigated the clinical characteristics and follow-up results of patients with a lower urinary tract inverted papilloma (IP) in our hospital, with the intention of clarifying whether certain groups require more aggressive surveillance. Materials and Methods We conducted a retrospective study of lower urinary tract IP, using the pathology database of Taipei Veterans General Hospital, from September 1992 to February 2008. In total, 67 patients were enrolled. Patients' clinical characteristics, symptoms, tumor locations, and follow-up data were analyzed. Results Among the 67 patients diagnosed with IP, 59 were male and eight were female, with a mean age of 67.9 ± 12.4 years. Gross hematuria and lower-urinary-tract symptoms were the most common symptoms. All of the patients received transurethral resection as initial treatment. Thirty-eight of these patients were monitored for a median of 21 months (range: 3–168 months). Seven patients had synchronous urothelial malignancies, and one had recurrent IP during follow-up. No patient had subsequent urothelial carcinoma or IP recurrence without a synchronous or previous urothelial malignancy during follow-up. Conclusion There is a low incidence of developing a subsequent malignancy with a simple IP lesion during follow-up. Rigorous surveillance may be unnecessary in IP patients without a synchronous or previous urothelial malignancy.