Muscular hyperplasia of the lung: a clinical, radiographic, and histopathologic study.

The clinical, radiographic, and histopathologic characteristics of pulmonary muscular hyperplasia were analyzed in 13 patients who were seen over a 13 year period. The average follow-up period was 7.2 years (range, 1-13). Eight patients initially demonstrated interstitial disease radiographically and the radiographic diagnosis was "interstitial fibrosis." The radiographs of the other five patients exhibited only localized infiltrates initially--produced by bronchiectasis in three, inflammatory mass in one, and bronchial carcinoma in one. Histologic features were consistent with desquamative interstitial pneumonia in eight, usual interstitial pneumonia in one, and unspecified interstitial pneumonia in four. When tuberous sclerosis is absent, pulmonary muscular hyperplasia is probably an end stage of interstitial pneumonia.