ACUTE diffuse interstitial fibrosis of the lungs is a disease of unknown causation characterized by sudden onset of cough, hemoptysis, dyspnea, cyanosis, and fever. Death from cardiac failure or pulmonary asphyxia has occurred in the reported cases after an illness of a few weeks. The disease was first described by Hamman and Rich,1 who reported four cases and identified one instance from the previous literature.2 The detailed description of the pathologic anatomy that these authors presented established the fundamental change as diffuse proliferation of fibrous connective tissue which involved the interstitial tissue of the lungs, with subsequent alterations in the pulmonary circulation. Associated pathologic changes consisted of metaplasia of the epithelium of the bronchi and of the pulmonary alveolar lining, the formation of intra-alveolar hyaline membranes, and thickening of the pulmonary arterioles.
Since the original description by Hamman and Rich 10 additional instances of this disease have appeared in the