Central Nervous System Histiocytic and Dendritic Cell Neoplasm

**Semantic type:** Neoplastic Process

**Definition:** A neoplasm that originates from histiocytes and accessory cells and affects the central nervous system. It is usually associated with the presence of identical tumors outside the central nervous system. Representative examples include Langerhans cell histiocytosis, histiocytic sarcoma, and follicular dendritic cell sarcoma.