[A case report of the pathognomonic relationship between idiopathic interstitial pneumonia and silicosis]

A 67 year-old male complaining of cough and exertional dyspnea was hospitalized for evaluation of an abnormal chest shadow. Chest X-ray films revealed bilateral diffuse nodular shadows, honeycombing in the lower lung fields and pleural thickening suggestive of idiopathic interstitial pneumonia. He had worked as a boilerman and painting using various materials. Transbronchial lung biopsy did not reveal silicotic nodules or asbestos bodies. Analytical electron microscopic study demonstrated amounts of free silica without other elements and asbestos fibers. This case suggests a pathognomonic relationship between idiopathic interstitial pneumonia and silica inhalation.