A major renal artery aneurysm as the cause of a hydronephrosis with renovascular hypertension.

In general, renal artery aneurysms occur very rarely. This study reports on a 9-cm renal artery aneurysm which was erroneously thought to be a renal cyst, and which, as a result of depression of the renal parenchym and the ureteropelvic junction, led to arterial hypertension and consecutive, reduced function hydronephrosis.