Advancing the classification of hematolymphoid neoplasms together: for patients, medicine, and science.

A single, universally used tumor classification system is critical to ensure precision in patient care, clinical trial enrollment, and advancing therapy. Since the publication of the third edition of the World Health Organization (WHO) classification in 2001, the hematology and hematopathology community has benefited from a single, widely accepted classification system. However, in 2022, 2 separate classification systems of hematologic and lymphoid neoplasms emerged, namely the fifth edition of the WHO Classification of Haematolymphoid Tumours and the International Consensus Classification. This has created confusion and has led to a global call to action to return to a single classification system. In 2024, leaders of the Society for Hematopathology (SH) and the European Association for Haematopathology (EA4HP), together with the leadership of the WHO Classification of Tumours, developed a plan to bridge the division and unite around the next edition of the WHO Classification of Haematologic and Lymphoid Tumours (WHO6). This plan entails convening a classification advancement meeting (CAM), organized by the SH and EA4HP, with broad participation by pathologists, clinicians, and geneticists to discuss and debate updates and changes to the existing classifications. Published conclusions of the CAM meeting will be available for independent consideration by the editorial board of WHO6. We are convinced that engagement with the broader community and the leveraging of global expertise to unite around WHO6 will critically benefit patients, medicine, and science.