Primary mediastinal myelolipoma: A case report and review of the literature

Myelolipoma is a rare, benign neoplasm composed of mature adipocytes and hematopoietic tissue, mainly occurring in the adrenal glands. The majority of extra-adrenal myelolipomas have been identified in the presacral region and primary mediastinal myelolipoma is very rare. Computed tomography (CT) and magnetic resonance imaging (MRI) are effective methods to detect myelolipoma, while fine-needle aspiration (FNA) combined pathology is able to definitively rule out malignancy. There is no standard method of treatment for the disease. Small (<4 cm) asymptomatic tumors should be monitored, while symptomatic tumors or large (>7 cm) myelolipomas should be removed by surgery. This study describes a patient who presented with two mediastinal myelolipomas that were not encapsulated and presented as a string-of-pearls-type. The pathological diagnosis was myelolipoma and the patient did not relapse within the three years following resection.