<prompt> The diagnostic triad of exophthalmos, diabetes insipidus and bone lesions is characteristic ofFibrous dysplasiaLetterer-Sieve diseaseOsteoporosisHand-Schuller Christian disease  <response>: Hand-Schuller-Christian disease: It is a chronic disseminated form of histiocytosis involving both soft tissues and bones in older children of either sex. It is characterised by a triad of proptosis, diabetes insipidus and bony defects in the skull. Ref:- A K KHURANA; pg num:-397 