Don't be fooled by the fat: A rare case of renal cell carcinoma with intratumoural fat.

Angiomyolipoma (AML) is a benign renal tumour composed of fat, smooth muscle and blood vessels. Radiologic evidence of macroscopic fat within a solid renal lesion on computed tomography was historically thought to be pathognomonic for this condition. Herein, we report a case of an incidental solid renal cell mass with multiple foci of intra-tumoral fat, which was shown to be a clear cell renal cell carcinoma (RCC) at nephrectomy. Macroscopic fat within solid renal lesions does not exclude malignancy, evaluation of other radiologic features is necessary when RCC is suspected.