What is thymolipoma?
Thymolipoma is a rare, benign, slow-growing thymic neoplasm that may occur in any age group, although young adults are most commonly affected. It is a large, soft, encapsulated mass composed of mature adipose cells and thymic tissue. About 50% of patients are asymptomatic. On imaging, a thymolipoma often presents as a large anterior mediastinal mass that droops into the anteroinferior mediastinum, may occupy one or both hemithoraces, and is characterized by its ability to conform to adjacent structures and to change in shape after changes in patient positioning. Predominant fat attenuation on computed tomography (CT) ( Figure 20-5 ) or fat signal intensity on magnetic resonance imaging (MRI) with intermixed soft tissue components is seen. Complete surgical resection is curative.