[Stenosis of the upper renal pelvis: rare complication of an incomplete ureteral duplicity. Embryological investigation].

A stenosis of the upper pole of an incomplete renal duplication is presented. The prenatal diagnosis of a right renal ureteropyelic junction syndrome, isolated, with a normal amniotic liquid was confirmed at birth. Intravenous pyelogram 8 days after birth showed three right dilated calical groups with a dilated renal ureteropyelic junction, but an normal inferior calical group suspected a renal bifidity. Renal MagIII scintigraphy evaluated the anatomical and functional stenosis and indicated surgery. Postoperative followings were simple and results good 3 years after. From this rare case, embryogenesis is discussed.