Mediastinal granuloma and fibrosing mediastinitis.

Thirty-one patients with mediastinal granuloma and fibrosing mediastinitis were seen at the Mayo Clinic from 1975 through 1977. Review of this series reveals that surgery is necessary to establish a diagnosis if the lesions are noncalcified and indeterminate. Fibrosing mediastinitis most likely develops after rupture of the fibrocaseous material from mediastinal lymph nodes into the mediastinum. Thoracotomy, with evacuation of the granulomas, is recommended, especially when the lesions are large, in order to prevent subsequent fibrosing mediastinitis with involvement of the contiguous structures, such as the superior vena cava, azygos vein, trachea, esophagus, and left atrium. In most patients, obstruction of the superior vena cava develops slowly, and efficient collateral venous circulation occurs, allowing long-term survival and minimal disability.