Renal and hepatic angiomyolipomas in a child without evidence of tuberous sclerosis.

A renal neoplasia, displaying the typical features of angiomyolipoma (an admixture of smooth muscle cells, mature adipocytes and tangles of thick-walled blood vessels) was found in a nine-year-old boy. In addition, cytoplasmic crystalloid structures and HMB 45 positivity were found in smooth muscle cells. Similar findings were also observed in a small nodule of the liver. According to literature data, angiomyolipoma is very rare in children and almost exclusively associated with tuberous sclerosis. Our case suggest that the diagnostic hypothesis of angiomyolipoma can not be disregarded when a renal mass is identified in a young patient even in a clinical setting other than tuberous sclerosis.