Abstract

Abstract:Twenty-three cases of diffuse interstitial fibrosis of the lungs were reviewed. The initial symptom was dyspnea. Chest roentgenograms showed progressive, bilateral, reticular, diffuse pulmonary infiltrates most marked in the lower lobes. Four patients had proven collagen disease, and four had features suggestive of collagen disease. Diffuse interstitial fibrosis apparently is the result of a nonspecific reaction to a variety of injuries of the alveolar capillary wall. Microscopic patterns were divided into three phases: (1) early—interstitial edema, mixed chronic inflammatory reaction, and proliferation of fibroblasts; (2) intermediate—obliteration of terminal air spaces by organizing fibrous connective tissue; (3) late—obliteration of air spaces by scar tissue and microcyst formation. It appears that specific diagnosis and therapy will be dependent upon appreciation of the roles of hypersensitivity and autoimmunity. Biopsy of the lung done in the early phase and studied by light, electron, and fluorescence microscopy should lead to better understanding of the process and further development of differential diagnostic criteria.