Long term outcome of primary urothelial papilloma: a single institution cohort.

The aim of this study was to investigate the long term outcome of primary urothelial papilloma (UP). We retrieved 41 primary UP, diagnosed between January 2000 and December 2009. Follow-up was obtained by searching pathology and clinical electronic databases. Mean patient age was 57 years (range 30-84 years), with a male-to-female ratio of 1.9:1. Mean follow-up was 81 months (range 3-127 months). In 37 (90.2%) patients, no recurrence and/or progression were documented and no subsequent higher grade neoplasms were diagnosed. Three male patients were diagnosed with UP at 1, 31, and 43 months after the initial resection; the repeat diagnosis of UP at 1 month likely represented an incomplete resection. Thus, only two of 41 patients (4.9%) had a recurrent UP. One of these patients had a subsequent papillary urothelial neoplasm of low malignant potential (PUNLMP), 17 months after the recurrent UP (48 months after the initial UP). Only one additional male had a subsequent PUNLMP, 76 months after the initial UP. Thus, only two of 41 patients (4.9%) had a subsequent PUNLMP, both presenting with haematuria. Primary UP does not progress to UC when diagnosed using strict criteria, when no previous or concurrent neoplasms are documented, and when complete initial resection is performed.