[A case of proliferative cystitis forming ureterovesical junction obstruction].

We report a case of proliferative cystitis forming ureterovesical junction obstruction. A 28-year-old man presented with a complaint of gross hematuria. Abdominal ultrasonography revealed left hydronephrosis and bladder tumor. Drip infusion pyelography (DIP) demonstrated left ureterovesical junction obstruction and cystoscopic findings appeared papillary sessile tumor around the bladder neck, trigone, and bilateral ureteral orifice. Transurethral resection of the bladder tumor (TURBT) was performed. The pathological diagnosis of the tumor was proliferative cystitis and confirmed that left ureterovesical junction obstruction was derived from proliferative cystitis. The tumor was not responsive to medical treatment. After the 4th TURBT, the tumor was completely resected, and left hydronephrosis and ureterovesical junction obstruction were improved. One year after the last operation, there is no evidence of recurrence of the tumor. Tumor formation arising from proliferative cystitis is relatively rare. Pathogenesis and management of this rare condition are discussed.