[Inverted papilloma of the ureter]

Two cases of ureteral inverted papilloma are reported. Case 1: A 48-year-old male had asymptomatic gross hematuria and filling defect of left middle ureter on intravenous pyelography. Segmental resection of ureter was performed. The specimen was a 1 cm polypoid lesion with histologic features resembling "multifocal bud-like proliferation", which was reported as the initial stage of the inverted urothelial tumor by Kunze et al. Case 2: A 64-year-old female with asymptomatic gross hematuria and complete obstruction of left middle ureter on ante- and retrograde pyelograms. Total nephroureterectomy was performed. A 4 cm lobulated and pedunculated lesion with histologic features of typical inverted urothelial papilloma was resected. Twenty-one cases of ureteral inverted papilloma in the literature, including our cases, are analyzed.