title: A case report and literature review of "primary" pulmonary histiocytosis X of childhood.
abstract: "Primary" pulmonary histiocytosis X, a well-described entity in young adult males in which pulmonary disease is the overriding site of involvement, is exceedingly rare in children younger than 15 years old. We report a new case in a 2-year-old male and review other reported prepubertal cases. The diagnosis of pulmonary histiocytosis X is based on examination of lung tissue. Langerhans cells containing Birbeck granules, seen by electron microscopy, are virtually pathognomonic of histiocytosis X. These Langerhans cells also react with a monoclonal antibody (OKT6) as well as with antibody to S-100 protein. Based on the lack of consensus for the appropriate treatment of pulmonary histiocytosis X and on our patient's favorable response, we recommend initial therapy with corticosteroids alone, reserving more toxic agents for patients who fail to respond to this initial therapy.
mesh_terms: D001847:Bone Diseases / Q000188:drug therapy; D004917:Erythromycin / Q000627:therapeutic use; D005500:Follow-Up Studies; D006646:Histiocytosis, Langerhans-Cell / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology*; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D007801:Langerhans Cells / Q000648:ultrastructure; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008854:Microscopy, Electron; D011241:Prednisone / Q000627:therapeutic use; D011859:Radiography; D009418:S100 Proteins / Q000032:analysis
chemical_list: D009418:S100 Proteins; D004917:Erythromycin; D011241:Prednisone