Late ureteral obstruction mimicking rejection after renal transplantation.

Ureteral obstruction occurring five years or more after renal transplantation is uncommon and may mimic allograft rejection. In 2 patients who had received cadaveric renal allograft, ureteral obstruction was detected six and one-half and five and one-half years after transplantation. In both patients, surgery was needed to restore normal renal function and to prevent further renal damage. Excretory urography is important in the follow-up of patients who have undergone renal transplantation, and conditions such as ureteral obstruction should be ruled out before antirejection treatment is started.