Retroiliac ureter with contralateral transverse malrotation of kidney: treated by crossed ureterocaliceal anastomosis.

We report a case of congenital bilateral urinary tract anomalies presenting as an abdominal mass with chronic renal failure. The anomalies comprised a retroiliac ureter with grade IV vesicoureteral reflux on the right side, which resulted in a nonfunctioning pyonephrotic right kidney, and a transversely malrotated hydronephrotic left kidney with a calculus. An initial attempt to improve the drainage of the left kidney by posterior transposition of the ureter failed. Subsequently, right nephrectomy and crossed ureterocaliceal anastomosis with the right ureter were performed. The reflux was treated by a ureteral tunnel advancement technique.