Horseshoe Kidney : Hydronephrosis

Horseshoe Kidney – Hydronephrosis: Hydronephrosis is seen in about one-third of horseshoe kidneys. The etiology may be: 1) ureteropelvic junction obstruction due to high insertion of ureter into the renal pelvis, abnormal course of ureter ventral to the connecting piece, and aberrant renal vessels causing extrinsic compression of the ureter; or 2) non-obstructing causes such as vesicoureteral reflux. This autopsy photo from an infant shows several features. Note the fetal lobulation in both kidneys. The right kidney is smaller. There is a bridge of tissue connecting the two lower poles. There is bilateral hydronephrosis secondary to vesicoureteral reflux.