The fifth edition of the WHO classification of mature B‐cell neoplasms: open questions for research

• DOI: 10.1002/path.6246
• Publication Date: 2024-01-05T15:11:30Z
• Authors: Sarah E Coupland; Ming‐Qing Du; Judith A Ferry; Daphne de Jong; Joseph D Khoury; Lorenzo Leoncini; Kikkeri N Naresh; German Ott; Reiner Siebert; Luc Xerri
• Keywords: Follicular lymphoma; BCL6; B-cell lymphoma

Abstract The fifth edition of the World Health Organization Classification Haematolymphoid Tumours (WHO‐HAEM5) is product an evidence‐based evolution revised fourth with wide multidisciplinary consultation. Nonetheless, while every classification incorporates scientific advances and aims to improve upon prior version, medical knowledge remains incomplete individual neoplasms may not be easily subclassified in a given scheme. Thus, optimal requires ongoing study, there are certain aspects some entities subtypes that require further refinements. In this review, we highlight selection these challenging areas prompt more research investigations. These include (1) ‘placeholder term’ splenic B‐cell lymphoma/leukaemia prominent nucleoli (SBLPN) accommodate many lymphomas previously classified as hairy cell leukaemia variant B‐prolymphocytic leukaemia, clear new start define their pathobiology; (2) how best classify BCL2 rearrangement negative follicular lymphoma including those BCL6 rearrangement, integrating emerging on various germinal centre subsets; (3) what spectrum non‐ IG gene partners MYC translocation diffuse large lymphoma/high‐grade they impact expression clinical outcome; investigate routine setting; (4) high‐grade otherwise specified 11q aberrations distinguish them from mimics characterise molecular pathogenetic mechanism. Addressing questions would provide robust evidence better entities/subtypes, diagnosis and/or prognostic stratification, leading patient care. © 2024 Authors. Journal Pathology published by John Wiley & Sons Ltd behalf Pathological Society Great Britain Ireland.