WHO classification of haematolymphoid tumors

Last revised by Joshua Yap on 16 Mar 2023

The World Health Organization (WHO) classification of haematolymphoid tumors is the most widely used pathologic classification system for hematopoietic and lymphoid neoplasms. The current revision 1, known as the 5th edition, was published in 2022 and supersedes the 4th edition revised published in 2016.


Myeloid proliferations and neoplasms
Myeloid precursor lesion
  • clonal hematopoiesis

  • clonal cytopenias of undetermined significance

Myeloproliferative neoplasms
  • mastocytosis

    • cutaneous mastocytosis

    • systemic mastocytosis

    • mast cell sarcoma

Myelodysplastic neoplasms
Myelodysplastic/myeloproliferative neoplasms
Acute myeloid leukemia
  • acute myeloid leukemia with defining genetic abnormalities

    • acute promyelocytic leukemia with PML::RARA fusion

    • acute myeloid leukemia with RUNX1::RUNX1T1 fusion

    • acute myeloid leukemia with CBFB::MYH11 fusion

    • acute myeloid leukemia with DEK::NUP214 fusion

    • acute myeloid leukemia with RBM15::MRTFA fusion

    • acute myeloid leukemia with BCR::ABL1 fusion

    • acute myeloid leukemia with KMT2A rearrangement

    • acute myeloid leukemia with MECOM rearrangement

    • acute myeloid leukemia with NUP98 rearrangement

    • acute myeloid leukemia with NPM1 mutation

    • acute myeloid leukemia with CEBPA mutation

    • acute myeloid leukemia, myelodysplasia-related

    • acute myeloid leukemia with other defined genetic alterations

  • acute myeloid leukemia, defined by differentiation

    • acute myeloid leukemia with minimal differentiation

    • acute myeloid leukemia without maturation

    • acute myeloid leukemia with maturation

    • acute basophilic leukemia

    • acute myelomonocytic leukemia

    • acute monocytic leukemia

    • acute erythroid leukemia

    • acute megakaryoblastic leukemia

  • myeloid sarcoma

Myeloid neoplasms, secondary
Myeloid/lymphoid neoplasms
  • myeloid/lymphoid neoplasms with eosinophilia and gene rearrangement

    • myeloid/lymphoid neoplasms with PDGFRA rearrangement

    • myeloid/lymphoid neoplasms with PDGFRB rearrangement

    • myeloid/lymphoid neoplasms with FGFR1 rearrangement

    • myeloid/lymphoid neoplasms with JAK2 rearrangement

    • myeloid/lymphoid neoplasm with FLT3 rearrangement

    • myeloid/lymphoid neoplasm with ETV6::ABL1 fusion

    • myeloid/lymphoid neoplasms with other tyrosine kinase gene fusions

Acute leukaemias of mixed or ambiguous lineage
  • acute leukemia of ambiguous lineage with defining genetic abnormalities

    • mixed-phenotype acute leukemia with BCR::ABL1 fusion

    • mixed-phenotype acute leukemia with KMT2A rearrangement

    • acute leukemia of ambiguous lineage with other defined genetic alterations

  • acute leukemia of ambiguous lineage, immunophenotypically defined

    • mixed-phenotype acute leukemia, B/myeloid

    • mixed-phenotype acute leukemia, T/myeloid

    • mixed-phenotype acute leukemia, rare types

    • acute leukemia of ambiguous lineage, NOS

    • acute undifferentiated leukemia

Histiocytic / dendritic cell neoplasms
Plasmacytoid dendritic cell neoplasms
Langerhans cell and other dendritic cell neoplasms
  • Langerhans cells neoplasms

  • other dendritic cell neoplasms

    • indeterminate dendritic cell tumor

    • interdigitating dendritic cell sarcoma

Histiocyte/macrophage neoplasms
B-cell lymphoid proliferations and lymphomas
Tumor-like lesions with B-cell predominance
Precursor B-cell neoplasms
  • B-lymphoblastic leukaemias/lymphomas

    • B-lymphoblastic leukemia/lymphoma

    • B-lymphoblastic leukemia/lymphoma with high hyperdiploidy

    • B-lymphoblastic leukemia/lymphoma with hypodiploidy

    • B-lymphoblastic leukemia/lymphoma with iAMP21

    • B-lymphoblastic leukemia/lymphoma with BCR::ABL1 fusion

    • B-lymphoblastic leukemia/lymphoma with BCR::ABL1-like features

    • B-lymphoblastic leukemia/lymphoma with KMT2A rearrangement

    • B-lymphoblastic leukemia/lymphoma with ETV6::RUNX1 fusion

    • B-lymphoblastic leukemia/lymphoma with ETV6::RUNX1-like features

    • B-lymphoblastic leukemia/lymphoma with TCF3::PBX1 fusion

    • B-lymphoblastic leukemia/lymphoma with IGH::IL3 fusion

    • B-lymphoblastic leukemia/lymphoma with TCF3::HLF fusion

    • B-lymphoblastic leukemia/lymphoma with other defined genetic alterations

    • B-lymphoblastic leukemia/lymphoma, NOS

Mature B-cell neoplasms
Hodgkin lymphoma
Plasma cell neoplasms and other diseases with paraproteins
T-cell and NK-cell lymphoid proliferations and lymphomas
Tumor-like lesions with T-cell predominance
Precursor T-cell neoplasms
Mature T-cell and NK-cell neoplasms
  • mature T-cell and NK-cell leukaemias

  • primary cutaneous T-cell lymphoid proliferations and lymphomas

    • primary cutaneous CD4-positive small or medium T-cell lymphoproliferative disorder

    • primary cutaneous acral CD8-positive T-cell lymphoproliferative disorder

    • mycosis fungoides

    • primary cutaneous CD30-positive T-cell lymphoproliferative disorder: lymphomatoid papulosis

    • primary cutaneous CD30-positive T-cell lymphoproliferative disorder: primary cutaneous anaplastic large cell lymphoma

    • subcutaneous panniculitis-like T-cell lymphoma

    • primary cutaneous gamma/delta T-cell lymphoma

    • primary cutaneous CD8-positive aggressive epidermotropic cytotoxic T-cell lymphoma

    • primary cutaneous peripheral T-cell lymphoma, NOS

  • intestinal T-cell and NK-cell lymphoid proliferations and lymphomas

    • indolent T-cell lymphoma of the gastrointestinal tract

    • indolent NK-cell lymphoproliferative disorder of the gastrointestinal tract

    • enteropathy-associated T-cell lymphoma

    • monomorphic epitheliotropic intestinal T-cell lymphoma

    • intestinal T-cell lymphoma, NOS

  • hepatosplenic T-cell lymphoma

  • anaplastic large cell lymphoma

  • nodal T-follicular helper (TFH) cell lymphoma

  • peripheral T-cell lymphoma, NOS

  • EBV-positive NK-cell and T-cell lymphomas

    • EBV-positive nodal T- and NK-cell lymphoma

    • extranodal NK/T-cell lymphoma

  • EBV-positive T-cell and NK-cell lymphoid proliferations and lymphomas of childhood

    • severe mosquito bite allergy

    • hydroa vacciniforme lymphoproliferative disorder

    • systemic chronic active EBV disease

    • systemic EBV-positive T-cell lymphoma of childhood

Stroma-derived neoplasms of lymphoid tissues
Mesenchymal dendritic cell neoplasms
  • follicular dendritic cell sarcoma

  • EBV-positive inflammatory follicular dendritic cell sarcoma

  • fibroblastic reticular cell tumor

Myofibroblastic tumors
  • intranodal palisaded myofibroblastoma

Spleen-specific vascular-stromal tumors
Genetic tumor syndromes

Changes from prior versions

The classification follows the Human Genome Organization Gene Nomenclature Committee recommendations which includes the new designation of gene fusions using double colons (::) 2.

"Tumor-like" lesions are a new category. This is grouped into lesions with B-cell predominance (which includes the new additions Castleman disease and IgG4-related disease) and lesions with T-cell predominance.

Lymphoproliferative disorders and lymphomas associated with primary immunodeficiencies and HIV have been regrouped within the new "lymphoid proliferations and lymphomas associated with immune deficiency and dysregulation" category, which is itself classified under "mature B-cell neoplasms". Similarly post-transplant lymphoproliferative disorders (PTLD) is no longer a separate classification and is now encompassed within the same group. These changes aim to shift the focus from the disease background to the histologic and pathogenetic features that they share 3.

Two other entities have been removed:

  • B-cell prolymphocytic leukemia

  • NK-lymphoblastic leukemia/lymphoma

A new category of stroma-derived neoplasms unique to the lymph node and spleen has been included (soft tissue tumors not specific to the lymph node or spleen such as hemangioma or angiosarcoma are covered in the WHO classification of soft tissue tumors).

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