Idiopathic congenital hemihypertrophy with associated ipsilateral benign nephromegaly.

Two cases of idiopathic congenital hemihypertrophy with ipsilateral benign nephromegaly are presented. Excretory urography usually differentiates benign renal enlargement from Wilm's tumor in these patients. Angiography is indicated in equivocal cases. The clinical features, differential diagnosis, associated conditions, and importance of radiologic reevaluation in patients with hemihypertrophy are discussed.