Subcommittees

Seven subcommittees were established at the beginning of the 6th edition. Two subcommittees with similar mandates were later merged, meaning there are currently six subcommittees.

Their role is to review information in their domains and provide input to the standing and expert members of the editorial board for consideration in the 6th edition of the WHO Classification of Tumours (also known as the WHO Blue Books). 
The subcommittees are composed of members who are experts in their field and are chaired by a member of the Standing Editorial Board.

  • Genetics and Genomics
  • Computational Pathology
  • WCT-LMIC Liaison
  • Tumour Harmonization
  • Imaging and Radiology
  • Tumour Definition and Clarification (formed when the two subcommittees below fused)
    • Gray Zone and Rare Tumours 
    • Tumour Clarification and Refining

 

Genetics and Genomics subcommittee

Goal: To provide information and guidance on new molecular and genetic advances.

Membership
Chair: Hodge, Jennelle C.
Co-chair(s): Ewalt, Mark D.
Members: 
Armon, Subasri
Cooper, Wendy A.
Fernandez-Cuesta, Lynnette
Fox, Stephen B.
Khoury, Joseph D.
Liang, Zhiyong
Lindeman, Neal
Netto, George J.
Schmitt, Fernando
Sepulveda, Antonia R.
Tadross, John A.
Yatabe, Yasushi
Zhang, Bo

Guidelines

The committee has developed the following guidelines:

  • Genetics/genomics information guidelines for editors and authors
  • Supplemental guidelines for the inclusion of genetics/genomics under each standard section subheading (Subtype(s), Etiology, Pathogenesis, Diagnostic molecular pathology, etc.)
  • Guidelines for the inclusion of genetic tumour syndromes in organ-specific volumes
  • Each volume’s molecular genetics representative will be the point person for the application of these guidelines.

 

Computational Pathology subcommittee

Goal: To facilitate the adoption of computational pathology, including artificial intelligence (AI) in the WHO Classification of Tumours, and to expand the existing library of whole slide images (WSIs).

Membership
Chair: Eden, Michael
Co-chair(s): van der Laak, Jeroen; Singh, Rajendra
Members:
de la Fouchardière, Arnaud
Eloy, Catarina
Foll, Mathieu
Goh, Vicky
Ishikawa, Shumpei
Khoury, Joseph D.
Liang, Zhiyong
Moulin, Pierre
Pantanowitz, Liron
Tan, Puay Hoon
Tizhoosh, Hamid Reza
Zlobec, Inti

Guidelines

  • At least one high-quality WSI per tumour type, accompanied by a legend (stating the tissue origin, diagnosis, and points of interest), the name of the reporting pathologist(s), and the name of the diagnosing institution
  • Use of AI tools to be expanded within the introductions
  • The system should be robust enough to be used with low-bandwidth connections
  • Consider annotations / short educational videos explaining the WSI, to expand the audience that could look at histology
  • Consider access to images from a variety of devices (PC, phones, tablets, etc.)

 

WCT-LMIC Liaison subcommittee

Goal: To ensure that the WHO Classification of Tumours is relevant and useful worldwide, and to devise ways to mitigate the impact of molecular classifications in low- and middle-income (LMIC) settings.

Membership
Chair: Field, Andrew S.
Co-chair(s): 
Members: 
Akkari, Yassmine
De Falco, Giulia
de Jong, Daphne
De Silva, Chandu
Jorda, Merce
Kanagal-Shamanna,
Kench, James G.
Leite, Katia R.M.
Michelow, Pamela
Plotkin, Anna
Rabban, Joseph T.
Rekhi, Bharat
Sachin, Jadhav
Santosh, Vani
Sayed, Shahin
Reyes-Múgica, Miguel
Ud Din, Nasir

Guidelines

  • Present the current best practice, including all relevant ancillary testing
  • Present the histopathology and diagnostic criteria for each tumour, with an emphasis on providing a differential diagnosis based on the histopathological features
  • Indicate clearly if the diagnosis is not possible on histopathology alone
  • Include diagnostic pathways based on
    • histopathology alone
    • histopathology plus basic immunohistochemistry or
    • histopathology plus more complex immunohistochemistry, fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), or other molecular tests
  • Present the immunohistochemistry of each tumour using a tiered approach:
    • immunohistochemistry tests essential for the diagnosis (included in essential diagnostic criteria)
    • immunohistochemistry tests required to further refine the diagnosis
    • immunohistochemistry tests required to provide clinical prognostic and treatment information
  • Indicate whether next-generation sequencing and other molecular diagnostic tests are essential for the diagnosis (include in essential diagnostic criteria) or a desirable ancillary test; include histopathology clues to the diagnosis, and any surrogate immunohistochemistry or ancillary tests (e.g. FISH or PCR tests), that may help to make the diagnosis through an alternative pathway
  • Include a description of the cytopathology for each tumour type where possible
  • Include cytopathologists as authors where necessary

 

Tumour Harmonization subcommittee

Goal: To harmonize and maintain consistency of information across the WHO Blue Books on tumours occurring in different organs.

Membership
Chair: Netto, George J.
Co-chair(s): de Jong, Daphne
Members: 
Alaggio, Rita
Davidson, Ben
Davis, Jessica L.
Kench, James G.
Khoury, Joseph D.
Lubieniecki, Fabiana
Marino-Enriquez, Adrian
Martins Bezerra, Stephania
Rekhi, Bharat
Reyes-Múgica, Miguel
Rindi, Guido
Rous, Brian
Sayed, Shahin
Shi, Chanjuan
Varga, Zsuzsanna

Guidelines

Guidelines for including haematopathology tumours in organ-specific volumes:

  • Tumours unique to organ system (e.g. breast implant-associated anaplastic large cell lymphoma, primary testicular large B-cell lymphoma of immune-privileged sites)
  • Tumours with tropism to an organ system (e.g. mantle cell lymphoma involvement of the gastrointestinal tract)
  • Tumours that secondarily involve the organ system with high frequency
  • Less frequent entities can be presented in table format in the introduction, with references to the 5th edition of the Haematolymphoid tumours volume
  • Haematolymphoid tumours, 5th edition, provides the foundation for definitions and essential/desirable diagnostic criteria
  • Text may require adaptation to include organ-specific data or specific differential diagnostic considerations


Guidelines for including paediatric tumours:

  • Entities that predominantly/specifically (> 90% of cases) affect individuals in the paediatric age range (≤ 18 years) are to be explained in detail only in the Paediatric tumours volume or in a paediatric-dedicated chapter/section of an organ-specific volume; they can be mentioned briefly or included in tables in other volumes with a reference to the corresponding section in the Paediatric tumours volume
  • Harmonize nomenclature and essential/desirable diagnostic criteria across the WHO Blue Books

 

Imaging and Radiology subcommittee 

Goal: To develop a gold-standard image library for the 6th edition of the WHO Blue Books and for the web, envisioning a future radiology classification.

Membership
Chair: Goh, Vicky
Co-chair(s): Chowdhury, Rajat
Members: 
Beets-Tan, Regina
Chowdhury, Rajat
Chu, Winnie Chiu Wing
Falk Delgado, Anna
Jinzaki, Masahiro
Lopci, Egesta
Loughrey, Maurice B.
Nishino, Mizuki
Patkar, Deepak P.
Poon, Wai Lun
Pungavkar, Sona A.
van der Pol, Christian B.

Guidelines

  • Identify any key gaps in imaging
  • Use an evidence-based approach to guide inclusion of imaging information and figures in the WHO Blue Books
  • Ensure radiology input; name key radiologist for each book
  • Templates for imaging figures and other radiology information are being developed.

 

Tumour Definition and Clarification subcommittee 

Goal: To provide guidance and develop criteria for the inclusion of new tumour types; to clarify the definitions of grey zone, rare, and provisional entities; and to review the current classification to identify tumours that may require further clarification/refining.

Membership
Chair: Tse, Gary
Co-chair(s): Rous, Brian (Cooper, Wendy A.; Felix, Ana)
Members:
Agaimy, Abbas
Alaggio, Rita
Andre, Fabrice
Argani, Pedram
Bale, Tejus
Baumhoer, Daniel
Bibeau, Frederic
Brogi, Edi
Chan, John K.C.
Davis, Jessica L.
Eden, Michael
Fernandez-Cuesta, Lynnette
Kern, Izidor
Khoury, Joseph D.
Klebe, Sonja
Kulka, Janina
Le Loarer, François
Liang, Zhiyong
Loughrey, Maurice B.
Maeda, Daichi
Matias-Guiu, Xavier
Mino-Kenudson, Mari
Mukhopadhyay, Sanjay
Nakanuma, Yasuni
Nobusawa, Sumihito
Orosz, Zsolt
Rekhi, Bharat
Reyes-Múgica, Miguel
Rossi, Sabrina
Ryška, Aleš
Sapino, Anna
Sepulveda, Antonia R.
Shi, Chanjuan
Torbenson, Michael S.
Yantiss, Rhonda K.
Yoshida, Akihiko

Guidelines 

Definitions:

  • Tumour type (formerly “entity”): a distinct tumour that differs from other tumours in multiple parameters (e.g. clinical, location, histopathological, and/or molecular)
  • Subtype: a tumour that differs from the main tumour type in at least one dimension (clinical, histological, or genetic), preferably with a different treatment or outcome
  • Pattern: a tumour that differs from the main tumour type in morphological aspects only, but not in its underlying biological or molecular features, treatment, or outcome
  • Variant: this term should be reserved for the meaning “genetic variant”

Criteria for including a new tumour type in the WHO Classification of Tumours:

  • There is a unique combination of sufficiently distinct pathological features and/or clinically relevant characteristics (diagnostic, prognostic, therapeutically predictive) compared with current tumour types
  • Suggested level of evidence for a new entity:
    • At least two high-quality peer-reviewed case series of at least five cases (the editorial board will determine whether a given publication is of sufficient quality; case reports are not sufficient), from distinct investigator groups
  • Additional criteria when using genetic features to support creation of tumour entities:
    • One or more distinct molecular or cytogenetic features
    • Does not meet criteria under other tumour types with defining genetic abnormalities
    • Not based solely on therapy-related mutations

Provisional entities: 

  • The term "provisional" is used if there is uncertainty as to whether an entity is sufficiently distinct for inclusion
  • The term "emerging entity" should be avoided
  • Entities that do not fulfil criteria for inclusion as a new entity or a provisional entity could be covered in introduction sections as potential new entities
  • All entities listed in the 5th edition as “provisional” or “emerging” should be reassessed