Hand-Schüller-Christian disease is a clinically intermediate form of a spectrum of histiocytic disorders, which ranges from acute fulminant to chronic indolent disease. It primarily affects children, less often young adults, and rarely older adults.
Hand-Schüller-Christian disease has been described as a multifocal unisystem disease, meaning it involves multiple sites of one organ system, almost always bone . However, it is classically associated with the triad of diabetes insipidus, proptosis, and lytic bone lesions. This triad is only seen in about a third of patients.