Fat containing renal lesions

There are numerous fat-containing renal lesions, including:

• renal angiomyolipoma
• renal cell carcinoma (often has calcifications when contains macroscopic fat)
• Wilms tumor
• renal oncocytoma
• renal or perirenal lipoma/liposarcoma

Non-mass lesions may also occasionally contain fat:

• renal junction line
• fat in a renal scar
• renal sinus lipomatosis
• xanthogranulomatous pyelonephritis

Practical points

Fat-containing lesions in the perinephric space may also mimic a fat-containing renal lesion, including:

• adrenal myelolipoma 
• retroperitoneal liposarcoma