Classification of histiocytoses
| Histiocytosis group . | Diseases . |
|---|---|
| L Group | LCH |
| Indeterminate-cell histiocytosis (ICH) | |
| Erdheim-Chester Disease (ECD) | |
| Mixed LCH/ECD | |
| C Group | Cutaneous non-LCH |
| Xanthomatous granuloma (XG) family: JXG, AXG, SRH, BCH, GEH, PNH | |
| Non-XG family: cutaneous RDD, NXG, other | |
| Cutaneous non-LCH with a major systemic component | |
| XG family: XD | |
| Non-XG family: MRH | |
| R Group | Familial RDD |
| Sporadic RDD | |
| Classical RDD | |
| Extranodal RDD | |
| RDD with neoplasia or immune disease | |
| Unclassified | |
| M Group | Primary Malignant Histiocytoses |
| Secondary Malignant Histiocytoses | |
| H Group | Primary HLH: Monogenic inherited conditions leading to HLH |
| Secondary HLH (non-Mendelian HLH) | |
| HLH of unknown/uncertain origin |
| Histiocytosis group . | Diseases . |
|---|---|
| L Group | LCH |
| Indeterminate-cell histiocytosis (ICH) | |
| Erdheim-Chester Disease (ECD) | |
| Mixed LCH/ECD | |
| C Group | Cutaneous non-LCH |
| Xanthomatous granuloma (XG) family: JXG, AXG, SRH, BCH, GEH, PNH | |
| Non-XG family: cutaneous RDD, NXG, other | |
| Cutaneous non-LCH with a major systemic component | |
| XG family: XD | |
| Non-XG family: MRH | |
| R Group | Familial RDD |
| Sporadic RDD | |
| Classical RDD | |
| Extranodal RDD | |
| RDD with neoplasia or immune disease | |
| Unclassified | |
| M Group | Primary Malignant Histiocytoses |
| Secondary Malignant Histiocytoses | |
| H Group | Primary HLH: Monogenic inherited conditions leading to HLH |
| Secondary HLH (non-Mendelian HLH) | |
| HLH of unknown/uncertain origin |
Adapted from Emile et al.21
AXG, adult xanthogranuloma; BCH, benign cephalic histiocytosis; GEH, generalized eruptive histiocytosis; JXG, juvenile xanthogranuloma; MRH, multicentric reticulohistiocytosis; NXG, necrobiotic xanthogranuloma; PNH, progressive nodular histiocytosis; RDD, Rosai-Dorfman Disease; SRH, solitary reticulohistiocytoma; XD, xanthoma disseminatum.