Giant mediastinal thymolipoma simulating cardiomegaly.

Thymolipomas are rare anterior mediastinal tumors composed of mature adipose tissue and benign thymic tissue and they may rarely simulate cardiomegaly on chest radiograph. We report an adult male who presented with progressive dyspnea of 2 months' duration. Clinical examination was unremarkable. Chest radiograph showed enlarged cardiac silhouette. Computed tomography of chest revealed a giant anterior mediastinal noncontrast enhancing mass partially wrapping around the heart. A needle biopsy obtained lymphomatous material that was diagnosed as thymolipoma. The tumor was successfully removed en bloc through a median sternotomy. Histopathological examination confirmed thymolipoma. We emphasize the importance of considering mediastinal tumors as a differential diagnosis in patients with progressive dyspnea without any obvious cause and chest radiograph showing enlarged cardiac silhouette.