[Histiocytosis X--results of a long-term clinical study].

Reported is a clinical follow-up study in 15 patients with Histiocytosis X. The time of observation varied between 2 and 17 years. In centre of analysis are results of lung function tests and radiological findings. The analysis allows the following conclusions: Classification of patients in early stage and late stage has great prognostic importance. Long-term prednisone therapy in the early stage prevents progression of disease in most cases. In spite of consequent therapy in single cases recurrences and transition in late stage have been observed. Prognosis in patients in late stage is worse than in patients in early stage. In these cases the long-term prednisone therapy is not able to prevent progression of the disease.