Oncocytic angiomyolipoma of the kidney: a case report.

We describe a case of oncocytic angiomyolipoma composed of polygonal eosinophilic cells, that shares many features with renal oncocytoma. It was composed of alveolar structures, with accumulation of foamy histiocyte-like cells surrounding large globules of acellular, nonfibrillary, densely eosinophilic basal membrane-like substance. Immunohistochemically, there was focal reactivity for HMB45 and negativity for the epithelial markers. Oncocytic angiomyolipoma lacks the atypical features of the recently described epithelioid variant of angiomyolipoma. None of the reported cases have been associated with tuberous sclerosis.