{"entity":{"id":"lymphoma-classification-2022","kind":"term","name":"The two lymphoma classifications of 2022 (WHO-HAEM5 and ICC)","aka":["WHO-HAEM5","WHO fifth edition","International Consensus Classification","ICC 2022","WHO Classification of Haematolymphoid Tumours"],"tldr":"Since 2022 there have been two reference classifications of lymphoma rather than one, published within months of each other by overlapping groups of experts. They agree about most diseases and disagree about a handful of names and boundaries, so the same biopsy can carry two different diagnoses depending on which book the pathologist used.","summary":"The fifth edition of the WHO Classification of Haematolymphoid Tumours (WHO-HAEM5) and the International Consensus Classification of Mature Lymphoid Neoplasms (ICC) were both published in 2022. WHO-HAEM5 arranges diseases in a hierarchy of class, family and entity, and orders the entities within a family from the most indolent to the most aggressive. The ICC was produced by a Clinical Advisory Committee convened around the same evidence.\n\nThe disagreements that change what a patient is called:\n\nNodular lymphocyte predominant Hodgkin lymphoma. The ICC renamed it nodular lymphocyte predominant B-cell lymphoma by consensus, on the grounds that it differs biologically and clinically from classic Hodgkin lymphoma and is closely related to T-cell/histiocyte-rich large B-cell lymphoma. WHO-HAEM5 kept the old name, explicitly so as not to interfere with trials already recruiting, while stating that the new name is acceptable in preparation for adopting it later.\n\nHigh-grade B-cell lymphoma with MYC and BCL6 rearrangements. Both books removed these cases from the double-hit category defined by MYC and BCL2. WHO-HAEM5 reassigns them to diffuse large B-cell lymphoma or high-grade B-cell lymphoma not otherwise specified according to how the cells look. The ICC created a new provisional entity for them instead.\n\nThe double-hit entity itself. WHO-HAEM5 names it diffuse large B-cell lymphoma / high-grade B-cell lymphoma with MYC and BCL2 rearrangements, so that a tumour made of large cells and a tumour made of blastoid cells can carry the same name once the genetics are known. The ICC keeps high-grade B-cell lymphoma with MYC and BCL2 rearrangements as the name and asks that the appearance be reported alongside.\n\nExtranodal NK/T-cell lymphoma. WHO-HAEM5 dropped the qualifier nasal type, because the disease occurs at several extranodal sites. The ICC retains it.\n\nLymphomas of immune-privileged sites. WHO-HAEM5 created a single entity grouping primary large B-cell lymphoma of the central nervous system, of the vitreoretina and of the testis. The ICC discussed the same grouping and decided it was premature, while recognising primary diffuse large B-cell lymphoma of the testis as an entity in its own right.\n\nPrimary cutaneous marginal zone disease. WHO-HAEM5 made it a separate entity and calls it a lymphoma. The ICC made it a separate entity and calls it a lymphoproliferative disorder, which is a statement about how dangerous it is rather than about what it is.\n\nThe nodal T-follicular helper cell lymphomas. WHO-HAEM5 names the family nodal T-follicular helper cell lymphoma, with the angioimmunoblastic type as the prototype. The ICC calls the same family follicular helper T-cell lymphoma. Both replace the older name angioimmunoblastic T-cell lymphoma with a longer one.\n\nWhat a reader should do with this. If a report, a second opinion and a trial protocol give three names, they are probably describing one disease in three vocabularies, and asking which classification each used is a reasonable question to put to the haematologist.","asOf":"2026-09-29","links":[{"label":"WHO Classification of Haematolymphoid Tumours, 5th edition: lymphoid neoplasms (Alaggio, Leukemia 2022)","url":"https://doi.org/10.1038/s41375-022-01620-2"},{"label":"International Consensus Classification of Mature Lymphoid Neoplasms (Campo, Blood 2022)","url":"https://doi.org/10.1182/blood.2022015851"}],"tags":["heme","lymphoma"],"related":["lymphoma-type","lymphoma-b-versus-t-cell","lymphoma-indolent-versus-aggressive"],"cancers":["non-hodgkin-lymphoma","hodgkin-lymphoma","dlbcl","peripheral-t-cell-lymphoma"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Clinical"},"route":"/terms/lymphoma-classification-2022/","neighbours":{"term":[{"id":"lymphoma-b-versus-t-cell","kind":"term","name":"B-cell, T-cell and NK-cell lymphoma","route":"/terms/lymphoma-b-versus-t-cell/"},{"id":"lymphoma-indolent-versus-aggressive","kind":"term","name":"Indolent and aggressive lymphoma","route":"/terms/lymphoma-indolent-versus-aggressive/"},{"id":"lymphoma-type","kind":"term","name":"Lymphoma (tissue type)","route":"/terms/lymphoma-type/"}],"cancer":[{"id":"adult-t-cell-leukaemia-lymphoma","kind":"cancer","name":"Adult T-cell leukaemia/lymphoma","route":"/cancers/adult-t-cell-leukaemia-lymphoma/"},{"id":"alk-negative-anaplastic-large-cell-lymphoma","kind":"cancer","name":"ALK-negative anaplastic large cell lymphoma","route":"/cancers/alk-negative-anaplastic-large-cell-lymphoma/"},{"id":"alk-positive-anaplastic-large-cell-lymphoma","kind":"cancer","name":"ALK-positive anaplastic large cell lymphoma","route":"/cancers/alk-positive-anaplastic-large-cell-lymphoma/"},{"id":"breast-implant-associated-alcl","kind":"cancer","name":"Breast implant-associated anaplastic large cell lymphoma","route":"/cancers/breast-implant-associated-alcl/"},{"id":"cutaneous-t-cell-lymphoma","kind":"cancer","name":"Cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome)","route":"/cancers/cutaneous-t-cell-lymphoma/"},{"id":"dlbcl","kind":"cancer","name":"Diffuse large B-cell lymphoma","route":"/cancers/dlbcl/"},{"id":"ebv-positive-dlbcl","kind":"cancer","name":"EBV-positive diffuse large B-cell lymphoma","route":"/cancers/ebv-positive-dlbcl/"},{"id":"enteropathy-associated-t-cell-lymphoma","kind":"cancer","name":"Enteropathy-associated T-cell lymphoma","route":"/cancers/enteropathy-associated-t-cell-lymphoma/"},{"id":"extranodal-nk-t-cell-lymphoma","kind":"cancer","name":"Extranodal NK/T-cell lymphoma","route":"/cancers/extranodal-nk-t-cell-lymphoma/"},{"id":"gastric-malt-lymphoma","kind":"cancer","name":"Gastric MALT lymphoma","route":"/cancers/gastric-malt-lymphoma/"},{"id":"high-grade-b-cell-lymphoma-myc-bcl2","kind":"cancer","name":"High-grade B-cell lymphoma with MYC and BCL2 rearrangements (double-hit lymphoma)","route":"/cancers/high-grade-b-cell-lymphoma-myc-bcl2/"},{"id":"hodgkin-lymphoma","kind":"cancer","name":"Hodgkin lymphoma","route":"/cancers/hodgkin-lymphoma/"},{"id":"lymphomatoid-papulosis","kind":"cancer","name":"Lymphomatoid papulosis","route":"/cancers/lymphomatoid-papulosis/"},{"id":"mediastinal-grey-zone-lymphoma","kind":"cancer","name":"Mediastinal grey zone lymphoma","route":"/cancers/mediastinal-grey-zone-lymphoma/"},{"id":"monomorphic-epitheliotropic-intestinal-t-cell-lymphoma","kind":"cancer","name":"Monomorphic epitheliotropic intestinal T-cell lymphoma","route":"/cancers/monomorphic-epitheliotropic-intestinal-t-cell-lymphoma/"},{"id":"mycosis-fungoides","kind":"cancer","name":"Mycosis fungoides","route":"/cancers/mycosis-fungoides/"},{"id":"non-hodgkin-lymphoma","kind":"cancer","name":"Non-Hodgkin lymphoma (all types)","route":"/cancers/non-hodgkin-lymphoma/"},{"id":"peripheral-t-cell-lymphoma","kind":"cancer","name":"Peripheral T-cell lymphomas (including cutaneous T-cell lymphoma)","route":"/cancers/peripheral-t-cell-lymphoma/"},{"id":"plasmablastic-lymphoma","kind":"cancer","name":"Plasmablastic lymphoma","route":"/cancers/plasmablastic-lymphoma/"},{"id":"primary-cutaneous-anaplastic-large-cell-lymphoma","kind":"cancer","name":"Primary cutaneous anaplastic large cell lymphoma","route":"/cancers/primary-cutaneous-anaplastic-large-cell-lymphoma/"},{"id":"primary-effusion-lymphoma","kind":"cancer","name":"Primary effusion lymphoma","route":"/cancers/primary-effusion-lymphoma/"},{"id":"primary-testicular-lymphoma","kind":"cancer","name":"Primary large B-cell lymphoma of the testis","route":"/cancers/primary-testicular-lymphoma/"},{"id":"t-cell-histiocyte-rich-large-b-cell-lymphoma","kind":"cancer","name":"T-cell/histiocyte-rich large B-cell lymphoma","route":"/cancers/t-cell-histiocyte-rich-large-b-cell-lymphoma/"},{"id":"waldenstrom","kind":"cancer","name":"Waldenström macroglobulinaemia","route":"/cancers/waldenstrom/"}]}}