[Histiocytosis X (eosinophilic granulomatosis) of the lung (author's transl)].

Report of a 21-year old male with biopsy-proved (primary) isolated Histiocytosis X (eosinophilic granuloma) localized in the lungs. The disease prefers young males and leads to a non-characteristical fibrosis of the lung in cases of chronical course. Lung biopsy is the only certain method for diagnosis. Morphology, differential-diagnosis and aetiology of this rare disease are also considered.