Azygos lymph node enlargement as initial manifestation of underlying disease.

Azygos lymph node enlargement is usually an indication of advanced bronchogenic carcinoma, although it may occur in benign pulmonary disease. Often it is found in conjunction with enlargement of hilar and other mediastinal lymph nodes. Isolated azygos lymph node enlargement is unusual and demands tissue diagnosis. Four patients without other evidence of underlying disease were evaluated because of roentgenographic finding of azygos lymph node enlargement. Three had malignant disease and one reactive lymphoid hyperplasia. Current concepts of mediastinal lymphatic drainage are presented. Because of the likelihood of underlying malignancy, biopsy examination of an enlarged azygos node by cervical mediastinoscopy is indicated.