Persistent radiologic thoracic hypotransparency: A case report and review of the literature.

A thymolipoma is a slow-growing, anterior mediastinal tumor, rare in childhood. The authors present a report of a 4-year-old girl with persistent right thoracic hypotransparency on the chest radiograph. Computed tomography and magnetic resonance imaging revealed an anterior, well-limited, mediastinal mass of heterogeneous density, with lipomatous and soft tissue density areas. The tumor was totally excised and the histopathologic findings revealed a thymolipoma. A year and a half after surgery, the child remains well. This report enhances the relevance of differential diagnosis in the presence of persistent radiologic thoracic hypotransparency.