Angiomyolipoma: clinical metamorphosis and concepts for management.

In 10 years the diagnosis of renal angiomyolipoma was made in 44 patients (female-to-male ratio 8:1) at our institution; 4 cases were associated with tuberous sclerosis. Of these patients 29 underwent surgical exploration because of a renal mass; 11 patients with renal masses that were consistent with angiomyolipoma radiologically have not undergone exploration. Of the 4 patients with and the 29 patients without tuberous sclerosis 1 (25 per cent) and 2 (7 per cent), respectively, had renal cell cancer in association with angiomyolipoma. Metachronous involvement of the contralateral kidney has not been noted in any of our patients who underwent nephrectomy for unilateral involvement, nor has there been progression of the contralateral lesion in 3 patients with bilateral disease without tuberous sclerosis during a followup of about 6 years. Furthermore, we have not noted progression of lesions in the 11 patients under observation for a mean followup of almost 3 years. We recommend elective exploration and a renal preserving operation when possible, not only for patients with pain and hemorrhage but also for the complex multiple lesions occasionally seen in patients who do not have tuberous sclerosis. Lesions associated with tuberous sclerosis require surgical intervention only when they become symptomatic or enlarge silently.