Caliceal obstruction owing to a large parapelvic cyst: excretory urography, ultrasound and computerized tomography findings.

Benign parapelvic cysts are a common finding on radiology studies. Rarely, a parapelvic cyst may enlarge enough to obstruct the renal calices. We report a case in which computerized tomography following an excretory urogram and ultrasound proved to be especially helpful in the noninvasive evaluation of an obstructing parapelvic cyst.