Thymolipoma: Analysis of 27 cases

PURPOSE: To characterize the radiologic features of thymolipoma. MATERIALS AND METHODS: Twenty-seven cases of thymolipoma were reviewed. Clinical, radiologic, and pathologic findings were noted. RESULTS: The masses occurred in 15 male and 12 female patients (mean age, 26.7 years). All 27 tumors were in the anterior mediastinum; 22 were in the anterior inferior mediastinum. On frontal radiographs, 12 tumors simulated cardiomegaly. On lateral radiographs, 12 tumors draped over the ipsilateral hemidiaphragm, simulating diaphragmatic elevation. Computed tomographic scans (n = 11) demonstrated a mixture of fat and soft-tissue attenuation in 10 tumors corresponding to adipose and thymic elements found at microscopy. Magnetic resonance images (n = 2) demonstrated fat and soft-tissue signal intensity characteristics. Both types of studies showed a connection between tumor and thymus. CONCLUSION: Thymolipomas are anterior mediastinal masses that may conform to the shape of adjacent structures. The diagnosis is supported by imaging studies that demonstrate fat and soft tissue within the tumor.