Rheumatic pneumonitis: Pathologic features

Abstract

<h2>Summary</h2> Of 87 autopsied children, 3 to 16years old, who died of rheumatic fever, 54, or 62 per cent, had some degree of rheumatic pneumonitis. In most, only a small portion of lung was involved. Gross pulmonic findings were not distinctive, but the presence of grayishred, firm lungs that exuded little fluid in a child who died of rheumatic fever was suggestive of rheumatic pneumonitis. The most satisfactory microscopic criterion for the diagnosis of acute rheumatic pneumonitis is the presence of a focal intra-alveolar or intraductal exudate composed of fibrin, mononuclear cells, and protein-rich fluid. Fibrin was present in the form of either globular masses or membranes. In late stages, focal fibrosis was common, presumably resulting from organization of the exudate in its various forms. Fibrin thrombi in pulmonic capillaries and necrosis of alveolar walls were uncommon. No gross or microscopic findings in rheumatic pneumonitis are absolutely pathognomonic of rheumatic fever since all can be found in other conditions.