Atypical Pulmonary Inflammatory Reactions

¹ The Department of Pathology, University of Colorado School of Medicine.

1) A series of 10 cases has been presented with atypical pulmonary inflammatory reactions, probably of viral origin, that resemble closely those seen in chicken pox, rheumatic fever, and in primary atypical pneumonia.

2) The pulmonary changes failed to produce a clearcut clinical syndrome. As a rule, they supervened upon other diseases, predominantly cardiovascular disturbances.

3) The lesions include fibrinoid swelling of the walls of alveoli and blood vessels, septal-cell proliferation, mononuclear-cell exudate, hyaline membranes, occasional peppering with neutrophils, fibrinous plugs, "fibrinophagia," Masson bodies, and bronchiolitis obliterans. Inclusion bodies were not seen.

4) The inclusion of these reactions, thus described, among the larger group of atypical pneumonias of diverse etiology appears justified on the ground of their histologic pattern.

5) Presence of Masson bodies should no longer be considered as occurring only in rheumatic pneumonia.

6) Diffuse progressive interstitial pulmonary fibrosis, pulmonary adenomatosis, and alveolar-cell tumor of the lung may result from such atypical pulmonary inflammatory reactions.