CT evaluation of the anterior mediastinum: spectrum of disease.

Computed tomography (CT) is the study of choice for evaluating disease in the anterior mediastinum. Mediastinal CT is usually performed with intravenously administered contrast material, and spiral CT is the preferred technique for evaluating a mediastinal mass. CT demonstrates thymic hyperplasia and thymic cysts and can help differentiate thymoma and thymic Hodgkin lymphoma. It is also useful in staging Hodgkin lymphoma and non-Hodgkin lymphoma. In thyroid malignancy, CT can depict mediastinal extension and lymphadenopathy; it also allows detection of goiter and ectopic parathyroid glands. Germ cell tumors such as teratoma and seminoma have characteristic appearances at CT. CT can also demonstrate miscellaneous mediastinal masses, such as lymphangioma, hematoma, those due to fibrosing mediastinitis, and pericardial cysts. Adenopathy due to tuberculosis or sarcoidosis is evident at CT, as is osteomyelitis due to a postsurgical abscess. Finally, CT features can suggest the pathologic origin of metastasis in the anterior mediastinum.