2016 Histiocyte Society classification of histiocytoses

The 2016 Histiocyte Society classification of histiocytoses and neoplasms of macrophage-dendritic cell lineages is a proposed revision of the organization's initial classification system from 1987.


Histiocytes are mononuclear phagocytes that reside in tissues, including macrophages and dendritic cells. Histiocytoses are disorders characterized by the accumulation of cells derived from macrophages or dendritic cells.


L (Langerhans) group
C group: cutaneous and mucocutaneous non-Langerhans cell histiocytoses
  • cutaneous non-Langerhans cell histiocytoses
  • cutaneous non-Langerhans cell histiocytoses with a major systemic component
M group: malignant histiocytoses
  • primary malignant histiocytoses
  • secondary malignant histiocytoses (following or associated with another haematologic neoplasia)
  • subtypes
    • histiocytic
    • interdigitating cell
    • Langerhans cell
    • indeterminate cell
    • not specified
R group: Rosai-Dorfman disease and miscellaneous noncutaneous, non-Langerhans cell histiocytoses
  • familial Rosai-Dorfman disease
  • sporadic Rosai-Dorfman disease
    • classical (nodal) Rosai-Dorfman disease
    • extranodal Rosai-Dorfman disease
    • neoplasia-associated Rosai-Dorfman disease
    • immune disease-associated Rosai-Dorfman disease
  • other non-C non-L non-M non-H histiocytoses
H group: haemophagocytic lymphohistiocytosis and macrophage activation syndrome
  • primary haemophagocytic lymphohistiocytosis (Mendelian inherited conditions)
  • secondary haemophagocytic lymphohistiocytosis (apparently non-Mendelian)
  • haemophagocytic lymphohistiocytosis of unknown/uncertain origin
Share article

Article information

rID: 63514
System: Haematology
Tag: cases, refs
Synonyms or Alternate Spellings:
  • Histiocytosis

Support Radiopaedia and see fewer ads

Updating… Please wait.

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.