A 22-year-old black male presented with progressive dyspnea, a nonproductive cough, and new skin lesions. He was severely hypoxic, and had a severe restrictive defect on pulmonary function testing. A 2-cm lytic defect was noted on skull radiographs. A lung biopsy demonstrated pulmonary fibrosis. A biopsy of a skin lesion was consistent with a diagnosis of multifocal eosinophilic granuloma, or disseminated histiocytosis X. The case presents several unusual features of this uncommon disorder.