Protracted yet variable major pulmonary artery compression in sarcoidosis.

A case of thoracic sarcoidosis showing diffuse mediastinal lymphadenopathy was followed for a 6-month period with serial chest radiographs, perfusion lung scans, and pulmonary angiograms. Significant extrinsic pressure upon major pulmonary arteries from large lymph nodes of sarcoidosis was seen to cause marked restriction in pulmonary parenchymal perfusion on both scanning and angiography.