A case of posterior mediastinal myelolipoma and a literature review of its imaging manifestations.

Mediastinal myelolipoma is a rare condition and has no obvious symptoms. In the past 20 years, some clinical cases have been documented. However, the literature has not systematically summarized its imaging features. The aim of this paper is to present a case of right posterior mediastinal myelolipoma and to review and summarize its imaging features. Twenty-six articles were included in our study, which included a total of 26 patients and 33 lesions; 90.9% of the lesions were located in the mediastinum at the level from the 8th thoracic vertebral body to the thoracic 12th vertebral body. Among the cases with unilateral mediastinum, 68.4% of the cases were located in the right posterior mediastinum. Bilateral lesions accounted for almost one-fourth of all lesions. After contrast medium was injected, 93.9% of the lesions had mild to moderate enhancement; 84.8% of the lesions contained fat density; and 75.8%, 69.7%, 87.9%, and 75.8% of the lesions showed clear boundary, regular shape, heterogeneity and were encapsulated, respectively. Only 12.1% of the lesions contained calcification. An inhomogeneous mass in the right posterior mediastinum near the spine, including fat density, is the predominant imaging marker of most mediastinal myelolipomas.