Polyuric urinary tract dilatation with renal damage.

Polyuria of diabetes insipidus and psychogenic polydipsia can produce massive dilatation of the urinary tract in the absence of any mechanical obstruction. Renal failure in these cases is rare. We report the second case of nephrogenic diabetes insipidus with nonobstructive hydronephrotic renal damage. Temporary suprapubic drainage restored renal function to normal and decreased the upper tract dilatation. Renal function has been preserved for more than 10 years. Surgical intervention beyond temporary vesical drainage is unnecessary.