Complete nonunion of the ureterovesical junction with preservation of renal function

We report on a neonate with a history of failure to thrive who had a large right abdominal mass. Renal ultrasound showed a large cystic mass that arose from the upper pole of the hydronephrotic right kidney. Preoperative antegrade pyelography confirmed that the mass communicated with 1 kidney. Further evaluation revealed no communication of the ureter with the bladder or vagina. Exploratory surgery identified the mass and intraoperative pyelography revealed no communication with the bladder. After resection of the mass and nephrostomy placement, reimplantation of the right ureter demonstrated complete atresia of the distal right ureter. Preservation of the remaining renal parenchyma was possible, because the functioning lower pole collecting system communicated with the cystic mass that arose from the upper pole.