Myelolipoma of the adrenal gland found incidentally during abdominal ultrasound and computed tomography examinations.

We report a case of adrenal myelolipoma found incidentally during abdominal ultrasound (US) and computed tomography (CT) examinations for hypertension. The patient was a 34-year-old woman with a history of hypertension. In June 1992, she complained of dizziness and easy fatigability and went to a hospital, where she was diagnosed as very hypertensive. She was hospitalized for further examinations. Abdominal US and CT incidentally revealed a right adrenal tumor. The tumor was visualized as a hyperechoic mass on US and an inhomogeneous low density mass with inner fat density and focal calcification on CT. Magnetic resonance (MR) imaging visualized the tumor as a high signal intensity mass on both T1- and T2-weighted images. Since the tumor was relatively large and the possibility of malignancy could not be completely excluded, resection of the tumor was performed. The resected tumor, which measured 5.2 x 3.8 x 2.5 cm, was located in the right adrenal medulla and was composed of mature fat cells and bone marrow elements, with all the developmental stages of hematopoietic cells. Small areas of fresh hemorrhage and calcification were found. The fat cell component showed focal myxoid change, but there were no immature or atypical cells. These features were consistent with myelolipoma. The clinical and pathologic features of adrenal myelolipoma are discussed.