Clinical and radiologic features, lung function and therapeutic results in pulmonary histiocytosis X.

Clinical appearance, radiologic findings, lung function and results of corticosteroid therapy were analyzed in 42 adult cases of biopsy-proven pulmonary histiocytosis X. Symptoms were present in only 64%. Using the ILO classification 1980, the evaluation of chest radiographs revealed all categories of profusion, size and shape of nodules. The characteristic 'ring figures', i.e. thin-walled cysts, in the parenchyma were detected in 78% of conventional tomographies (n = 27) and in all patients examined by CT (n = 5). In patients with early disease, lung function tests (n = 26) including body plethysmography, pulmonary diffusing capacity and ergospirometry revealed that parameters of gas exchange are most sensitive (TL,CO 84%, KCO 72%). Bronchial reactivity to carbachol was significantly higher than in controls (n = 12). Lung perfusion scintigram showed an abnormal, but uncharacteristic pattern in 81% (n = 26). During corticosteroid therapy, no progression was observed (n = 36). 85% of patients with radiographic evidence of progressive disease improved after administration of corticosteroids (n = 14).