Interstitial lung disease in polymyositis and dermatomyositis. Clinical features and prognosis as correlated with histologic findings

Abstract

Open lung biopsies from 14 patients and autopsy tissue from one patient with polymyositis/dermatomyositis were reviewed in an attempt to correlate histologic features with clinical, radiographic, and prognostic variables. Three major groups based on histologic patterns were identified: bronchiolitis obliterans organizing pneumonia (BOOP), usual interstitial pneumonia (UIP), and diffuse alveolar damage (DAD). Patients with BOOP had a more favorable prognosis than did patients with UIP. Patients with DAD had a uniformly poor prognosis. One patient had a cellular interstitial pneumonia and did well. Histologic subclassification of the interstitial lung disease proved to be a better predictor of survival than did the radiographic appearance or the clinical presentation. These findings suggest that there is a broader range of histologic findings in polymyositis-dermatomyositis than is suggested in the literature and subclassification may be useful for prognosis.