Myelolipoma of the adrenal: two cases with ultrasound and CT findings.

Myelolipoma of the adrenal gland is a rare tumor composed of varying proportions of fat and bone marrow elements. In about half of the reported cases with radiologic findings the mass was radiolucent, indicating the presence of fat; the remainder were of soft tissue density or calcified. Arteriography is of limited value in diagnosis, since myelolipomas are typically avascular. With the advent of gray scale ultrasound and computed tomography (CT), fat can be detected in lesions which do not appear radiolucent on radiographs. Two cases of myelolipoma are reported in which ultrasound showed a markedly echogenic mass, an appearance chracteristic of lipomatous tumors. In the second case, the mass was of soft tissue density on radiographs, markedly echogenic on sonogram, and definitively fatty on CT scan. Ultrasound and CT are valuable techniques for making a preoperative diagnosis of this tumor.