Urothelium lining the papillary folds is thickened but there is no cytologic atypia. Papillary urothelial hyperplasia is sometimes discovered during the workup for hematuria. Such patients should receive close follow-up. The long-term biologic behavior of de novo papillary hyperplasia is uncertain. It is presumed to be a precursor to low-grade papillary urothelial tumors.