Erdheim-Chester Disease

**Definition:** A rare form of non-Langerhans-cell histiocytosis (HISTIOCYTOSIS, NON-LANGERHANS-CELL) with onset in middle age. The systemic disease is characterized by infiltration of lipid-laden macrophages, multinucleated giant cells, an inflammatory infiltrate of lymphocytes and histiocytes in the bone marrow, and a generalized sclerosis of the long bones.

**Tree numbers:** - C15.604.250.410.224

**Synonyms:** - Granulomatosis, Lipid