Pathophysiology of Interstitial Pulmonary Fibrosis:  Report of 19 Cases and Follow-Up with Corticosteroids

One of the most interesting and difficult problems of diagnosis and therapy is the dyspneic patient with radiological evidence of diffuse pulmonary infiltration in whom a lung biopsy is eventually obtained which shows an interstitial pneumonitis and fibrosis. The histologic pattern is often similar to that described by Hamman and Rich,¹ but the clinical course is likely to be more chronic than in the original cases. It is now recognized that some systemic diseases such as rheumatoid arthritis, scleroderma, and others occasionally may produce this lung picture. Frequently, however, careful investigation does not reveal any such recognizable disorder.

During the past 10 years we have studied 102 patients who by clinical and roentgenographic criteria appeared to have diffuse interstitial fibrosis of unknown etiology. From this group we have selected 19 patients for presentation here because (1) no possible etiologic factor could be elicited by historic review and by detailed