Abstract
Myelolipoma is a benign tumor characterized by mature adipocytes and normal myeloid cells. Myelolipoma mainly involves the adrenal gland and very rarely involves the mediastinum. Imaging features show lipid components. Here, we present an extremely rare case in which lipid components were not observed on computed tomography (CT) or magnetic resonance (MR) imaging; however, the results of a post-operative pathological examination led to the diagnosis of a posterior mediastinal myelolipoma. A 65-year-old man who was treated for hypertension and osteoporosis showed an abnormal shadow on a chest radiograph. A posterior mediastinal tumor of 27 mm in diameter was detected on chest CT, and a decreased signal intensity was not clearly observed on fat-suppressed MR imaging. The tumor was suspected to be a neurogenic tumor, and, therefore, thoracoscopic tumor extirpation was performed. On the basis of the results of the histopathological examination, the tumor was diagnosed as a myelolipoma. A follow-up examination showed no recurrence or hematologic abnormality for 14 months after the operation.
