Mediastinal lymph node biopsy in sarcoidosis.

Mediastinoscopy, in the skilled hands of a thoracic surgeon has proved to be a safe, cosmetically accepted procedure with negligible complications. It has yielded a high rate of diagnostic lymph node tissue; overall greater than 82% among patients with sarcoidosis, including patients presenting with pulmonary mottling only or with a normal chest radiograph. Among patients with lymphatic tuberculosis it enabled the isolation of human M. tuberculosis following culture of the lymph node removed on Löwenstein-Jensen medium in greater than 79% of cases. A precise histological diagnosis was obtained in all 14 patients presenting with hilar and/or paratracheal lymphadenopathy attributable to malignant disease.