Solution: An angiomyolipoma (AML) is a benign tumor composed of abnormal blood vessels, smooth muscle and fatty components. This should be your first thought when you see an intrarenal fatty mass. They can vary in size from a few mm to 25 cm in diameter and when you see multiple AML', you should consider the possibility of a syndrome such as Tuberous Sclerosis as was true in this case. 80% are isolated and 20% are associated with tuberous sclerosis with lymphangiomyomatosis being a less common association. They can be associated with hemorrhage and rupture, which can be life threatening. The CT showed a small foci of active bleeding, but they were unable to confirm with an angio for embolization



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