The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms

We herein present an overview of the upcoming 5th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms

Correction. "The 5th edition of The World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms" Leukemia. 2022 Jul;36(7):1720-1748

We herein present an overview of the upcoming 5th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms

Whole body‐diffusion weighted imaging for the assessment of treatment response in hairy cell leukaemia: A positive first step

Abstract We present the case of a patient diagnosed with hairy cell leukaemia (HCL) who subsequently developed biopsy confirmed bone lesions and underwent multiple lines of therapy. The reported incidence of bone lesions in HCL is 3%, and bony involvement can be associated with high tumour burden and aggressive disease. The commonly lytic bone lesions in HCL are difficult to accurately assess for response. Whole body diffusion weighted imaging (WB‐DWI) has been used clinically in multiple myeloma; we postulate clinical utility in HCL, where hypercellularity also applies. In our case, WB‐DWI appears to discriminate sites of active disease from bone response. We present the salient radiological and pathological images. To our knowledge, this is the first description of WB‐DWI in HCL; we support research of WB‐DWI in the staging, prognostication and response assessment of HCL