Table 3 Revised classification system of histiocytoses and malignancies macrophage-dendritic cell lineages
Group of histiocytic disorders | Histiocytosis |
|---|---|
1: L group | • Langerhans cell histiocytosis (LCH) • Indeterminate cell histiocytosis (ICH) • Erdheim-Chester disease (ECD) (mixed LCH and ECD) |
2: C group | Cutaneous LCH ▪ Xanthogranuloma (XG) family • Juvenile xanthogranuloma (JXG) • Adult xanthogranuloma (AXG) • Solitary reticulohistiocytoma (SHR) • BCH • GEH • PNH ▪ Non-XG family • Cutaneous Rosai-Dorfman disease • Necrobiotic xanthogranuloma (NXG) Cutaneous non-LCH with major systemic component • XG family; xanthoma disseminatum (XD) • Non-XG family multicentric reticulohistiocytosis (MRH) |
3: M group | Primary MH malignant histiocytoses Secondary malignant histiocytoses: (following or associated with another hematologic malignancy) |
4: R group | • Familial Rosai-Dorfman disease (RDD) - Classical (nodal) - Extra-nodal - RDD with neoplasia or immune disease - Other, non-C, non-L, non-M, non-H histiocytosis |
5: H group | • Primary hemophagocytic lymphohistiocytosis (HLH): Mendelian-inherited conditions that lead to HLH • Secondary HLH: non-Mendelian HLH • HLH of unknown origin |