Spontaneous peripelvic extravasation of urine as a cause of acute abdomen.

In eight patients with sudden onset of flank pain, urography showed extravasation of urine. The cause of peripelvic leakage was verified ureteral stone in four cases, stricture of the ureteropelvic junction in one, and unknown in three cases. Treatment was symptomatic in four cases, drainage in two and surgery in two cases. Seven patients recovered uneventfully, but one required nephrectomy. The prognosis in spontaneous urinary extravasation is usually good without drainage. Open surgery is seldom indicated.