Histopathology of aspiration pneumonia not associated with food or other particulate matter: a clinicopathologic study of 10 cases diagnosed on biopsy.

Aspiration pneumonia most often presents in surgical lung biopsies as a granulomatous pneumonia with acute inflammation, microabscesses, and a granulomatous reaction to food or other particulate matter. In this study of 10 patients with clinical aspiration in whom surgical lung biopsy was performed, 3 additional patterns of lung injury were seen: organizing pneumonia (4 patients); acute diffuse alveolar damage (3 patients); and chronic bronchiolitis (3 patients), in whom 2 had evidence of extensive pleuropulmonary fibrosis and scarring. This study adds to the earlier described literature on granulomatous reactions to food and particulate matter in the lung by alerting pathologists to other histopathologic manifestations of aspiration-induced lung injury in surgical lung biopsies.