Histiocytic and Dendritic Cell Neoplasm

**Semantic type:** Neoplastic Process

**Definition:** A group of rare tumors that affect the hematopoietic and lymphoid tissues. The cells of origin are the histiocytes and accessory cells. This category includes the following: Langerhans cell histiocytosis, Langerhans cell sarcoma, indeterminate dendritic cell histiocytosis, interdigitating dendritic cell sarcoma, histiocytic sarcoma, disseminated juvenile xanthogranuloma, Erdheim-Chester disease, Rosai-Dorfman-Destombes disease, ALK-positive histiocytosis, and follicular dendritic cell sarcoma.

**Synonyms:** - Histiocytic Neoplasm - Histiocytic and Dendritic Cell Neoplasms - Histiocytic and Dendritic Cell Tumors