title: Histiocytosis X with pericardial effusion: diagnosis questioned.
mesh_terms: D003937:Diagnosis, Differential; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008206:Lymphatic Diseases / Q000175:diagnosis; D010490:Pericardial Effusion / Q000209:etiology*