Minimal fat renal angiomyolipoma with central scar and stellate calcification mimicking a calyceal calculus.

Renal angiomyolipomas are benign neoplasms composed of varying amounts of adipose tissue, smooth muscles and blood vessels. They typically contain macroscopic fat, which is seen as negative attenuation on computed tomography. Calcification and scarring is rarely seen in renal angiomyolipomas. We report the case of a 40-year-old man who was found to have a renal angiomyolipoma with a central stellate scar and focal calcification. The lesion was initially misdiagnosed as a calyceal calculus.