Urothelial papilloma of the bladder - Clinical and biologic implications

BACKGROUND. An international consensus has been reached regarding diagnosti c criteria for papilloma of the urinary bladder. However, the incidences of recurrence and progression in patients with urothelial papilloma are uncer tain. METHODS. The population for this study consisted of 52 patients who were di agnosed with urothelial papilloma of the bladder at the Mayo Clinic between 1914 and 1998. All histologic slides were reviewed and fulfilled the diagn ostic criteria of urothelial papilloma from the 1998 World Health Organizat ion/International Society of Urological Pathology classification system. No patients had previous or coexistent urothelial carcinoma, and none were tr eated after biopsy. RESULTS. The mean patient age at diagnosis was 57 years (range, 22-89 years ). The male-to-female ratio was 1.9:1. The mean Follow-up was 9.8 years (ra nge, 0.1-58 years). Four patients developed recurrent papilloma (mean inter val from diagnosis to recurrence, 3.3 years); 1 other patient developed pap illary neoplasm of low malignant potential (Ta WHO Grade 1 papillary urothe lial carcinoma) 6 years after the initial diagnosis of papilloma. None of t hese patients developed dysplasia, carcinoma in situ, or invasive urothelia l carcinoma or died of bladder cancer. CONCLUSIONS. Patients with urothelial papilloma have a low incidence of rec urrence and rarely, if ever, develop urothelial carcinoma; [See editorial o n pages 1890-2 and related article on pages 2102-8, this issue.] Cancer 199 9;86:2098-101. (C) 1999 American Cancer Society.