Genitourinary Radiology > Adrenal Glands > Myelolipoma


Myelolipomas are a benign, nonfunctional tumor of the adrenal cortex composed of adipose and hematopoietic tissues with variable foci of hemorrhage. They are usually an incidental finding, though larger tumors may cause symptoms due to mass effect.

Plain films show a radiolucent suprarenal mass displacing the renal axis--especially if large.

Ultrasound shows a suprarenal lesion with increased echogenicity and decreased sound-through transmission beyond the mass.

On CT scan, myelolipomas appear as a well-defined, heterogeneous lesion with ocassional foci of calcification. Most are less than 5 cm but they may ocassionally be much larger (greater than 20 cm.).

MRI: high signal intensity on T1 (due to adipose tissue or methemoglobin from hemorrhage). If the adrenal mass contains macroscopic fat, then the lesion would get darked (saturate out) on fat saturation sequences.

Large left suprarenal mass (M) with low (fat) density seen on this plain film centered on the kidneys.  The left suprarenal mass had mass effect on the adjacent kidney distorting the upper pole and pushing the kidney inferiorly.

Enhanced CT scan of the abdomen shows a fatty mass (M) in the left adrenal gland (arrow shows body of adrenal).  The mass is the exact same density as the retroperitoneal fat (R) confirming this is a fatty lesion. HELP WITH LABELS

T2 weighted no fat saturation coronal image (a), T1 weighted fat saturated coronal image (b), T2 weighted fat saturation axial image and (d) T1 weighted fat saturation coronal image shows a fatty mass (M) in the right adrenal gland. The signal of this lesion is bright on non-fat saturation images but become dark on fat saturation images confirming a fat containing adrenal mass which is pathognomonic for myelolipoma.

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