“Nonspecific” Interstitial Pulmonary Fibrosis

Abstract

ELECTRON microscopy has only recently been applied to "idiopathic" interstitial pulmonary reactions. In 1971, we described a patient with interstitial granulomas and fibrosis indistinguishable from sarcoidosis.¹ A history of occupational exposure impelled electron microscopy and x-ray diffraction studies, which revealed talc crystals in his lungs. For the patient described below, we examined lung tissue that had shown severe interstitial fibrosis, with no evidence of mineral particles, on light microscopy. Although the patient had had no exposure to known pathogenic dusts, electron microscopy demonstrated ubiquitous fibrils of chrysotile asbestos, averaging 27.5 nm (275Å) in width and less than 100 nm ( . . .