Myelolipoma of the kidney: a seldom site for a rare extra-adrenal tumor

Myelolipoma of the extra-adrenal gland is a rare, benign tumor comprising mature fat tissue and hematopoietic elements. Most myelolipomas are asymptomic and discovered incidentally. We presented a 44-year-old male who was admitted to our hospital for right kidney dystrophy and renal calculus. Ultrasound examination of right kidneys showed hydronephrosis. Intravenous pyelography showed the right renal contour was unclear, with a circular high-density shadow inside. The nephrectomy was performed with renal myelolipoma as a final pathologic diagnosis.