PAPILLARY UROTHELIAL HYPERPLASIA - A PRECURSOR TO PAPILLARY NEOPLASMS

Precursor lesions of papillary urothelial neoplasms have not been well characterized. We reviewed the surgical pathology files of the Johns Hopkins Hospital and three regional hospitals from 1992 to present. Si xteen cases of papillary hyperplasia, defined as undulating urothelium arranged into thin mucosal papillary folds, were identified (in 11 me n and five women; age range, 40-89 years). Relative to the diagnosis o f papillary hyperplasia, nine patients had a history of papillary urot helial neoplasms; in one of these cases, the patient also had subseque nt papillary urothelial neoplasms, and two of these patients had concu rrent papillary urothelial neoplasms with papillary hyperplasia. In on e of these nine cases, papillary hyperplasia arose in the scar of a pr ior papillary urothelial neoplasm. In two cases, the patients had conc urrent, yet no prior history, of papillary urothelial neoplasms. Of th ese 11 cases, three had multiple resections showing papillary hyperpla sia over time. In case 12, the patient had a history of moderate uroth elial atypia. The remaining four patients had no history of papillary urothelial neoplasms or urothelial atypia. We describe papillary hyper plasia as a well-defined entity that is usually asymptomatic and gener ally found on routine follow-up cystoscopy for papillary urothelial ne oplasms. Papillary hyperplasia appears to be a precursor lesion of low -grade papillary urothelial neoplasms.