Difficulties in diagnosing and treating renal angiomyolipoma: report of three cases and review of the literature.

Renal angiomyolipoma is an uncommon benign tumor that presents diagnostic and therapeutic problems. It may be unilateral or bilateral; in its bilateral form it is usually associated with tuberous sclerosis. As a mass lesion of the kidney, it resembles renal cell carcinoma on pyelography and angiography, but computerized axial tomography and ultrasonography may provide a definitive diagnosis. This benign tumour should be treated conservatively to preserve renal function, but surgical intervention is necessary if renal cell carcinoma cannot be excluded completely.