Erdheim-Chester disease (MONDO_0018153, a Monarch Disease Ontology entry) (ECD), a non-Langerhans form of histiocytosis, is a multisystemic disease characterized by various manifestations such as skeletal involvement with bone pain, exophthalmos, diabetes insipidus, renal impairment and central nervous system (CNS) and/or cardiovascular involvement. Also known as: Erdheim Chester Disease, lipogranulomatosis, polyostotic sclerosing histiocytosis.