[Pulmonary histiocytosis X]

Morphologic studies of the lungs of 61 patients aged 15-62 years with pulmonary histiocytosis X revealed a different morphologic picture in relation to the duration of the disease. The most prevalent were primary and chronic forms characterized by the presence of histiocytic granulomas of varying size with blue-green inclusions, eosinophilia and corpuscles X in the macrophage cytoplasm. As the process progressed, fibrobullous changes occurred in the lungs. An open biopsy of the lungs and testing of the lavage macrophages for corpuscles X appears to be more informative and safe for the morphologic diagnosis of histiocytosis X.