The described lesion shows almost most of the typical imaging criteria of the classic adrenal myelolipoma. It is a benign adrenal tumor that is usually incidentally noted with macroscopic fat content. It can be bilateral or unilateral with a right side predilection. It is often hormonally inactive lesion

On CT, the presence of fat densities in a benign-looking suprarenal mass lesion is the key for the diagnosis. The non-fatty soft tissue component usually enhances due to hematopoietic tissue composition. 

Other suprarenal neoplasms can show macroscopic fat, but fat-containing malignancies of the adrenal gland are exceedingly rare, like fat-containing adrenal cortical adenoma/carcinoma. Other fat-containing retroperitoneal tumors also could be regarded like lipomas, angiomyolipomas, mature teratomas, and liposarcomas that should be differentiated so. 

Percutaneous fine-needle aspiration by US or CT guidance can confirm the diagnosis.

Case contributed by Dr. Reem Yehia

Ultrasound study contributed by Dr. Somia Elbadawy