A severe, stable obstructive defect in the airways in primary pulmonary histiocytosis X

An adult with biopsy-proven primary pulmonary histiocytosis X was followed-up over a period of 8 1/2 years. A severe obstructive defect was manifested by severely reduced rates of flow, a fall in the forced vital capacity from 2.6 L to 1.4 L, and a total lung capacity greater than 100 percent of the predicted normal value on three occasions. The patient has survived two episodes of respiratory failure. Her severe interstitial process may explain the development of obstruction of the airways.