The expanding spectrum of T-cell lymphomas with follicular helper T-cell phenotype and implications for differential diagnoses: A report of the 2023 SH/EA4HP Lymphoma Workshop Review

  

Authors:	Dogan, A.; Eren, O. C.; De Leval, L.
Review Title:	The expanding spectrum of T-cell lymphomas with follicular helper T-cell phenotype and implications for differential diagnoses: A report of the 2023 SH/EA4HP Lymphoma Workshop
Abstract:	Objectives The 2023 Society of Hematopathology/European Association for Haematopathology Workshop on Progress in Peripheral T- and NK-Cell Lymphomas addressed challenges in diagnosis, biomarkers, and molecular pathogenesis. Methods Session 1 of the workshop focused on T-follicular helper (TFH) lymphomas and related entities. Sixty-one cases were submitted, and their histology, phenotype, and genetics were reviewed. Results The panelists confirmed 46 cases as TFH lymphomas, more commonly angioimmunoblastic type than follicular or not otherwise specified. A small subset of patients were young adults. Expected immunophenotypic profile, with expression of pan T-cell markers and TFH-specific markers with subtle differences between the histologic subtypes was observed. Genetic analyses revealed classic genetic alterations associated with these tumors, including frequent mutations in epigenetic modifiers (eg, TET2, DNMT3A, and IDH2) and RHOA. A broad spectrum of clonal B-cell proliferations was associated with TFH lymphomas, including polymorphic proliferations to large B-cell lymphoma-like expansions, often associated with Epstein-Barr virus. The remaining 15 cases were reclassified with alternative diagnoses, underscoring the diagnostic challenges and complexity in distinguishing TFH lymphomas from other entities. Conclusions The cases highlighted the clinical and biological heterogeneity and complexity of TFH lymphomas and provided a framework for pathology workup and diagnosis as well as future research. © 2025 The Author(s). Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved.
Keywords:	adult; clinical article; human tissue; aged; middle aged; young adult; genetics; review; genetic analysis; cell proliferation; t lymphocyte; biological marker; phenotype; diagnosis, differential; differential diagnosis; pathology; tumor marker; histology; b lymphocyte; t cell lymphoma; lymphoma, t-cell; diagnosis; lymphoma; natural killer cell; immunophenotyping; t-lymphocytes, helper-inducer; follicular lymphoma; lymphoma, follicular; therapy; epstein barr virus; helper cell; dna methyltransferase 3a; etiology; workshop; diffuse large b cell lymphoma; humans; human; male; female; angioimmunoblastic; biomarkers, tumor; tfh cell; t follicular helper cells; follicular helper t-cell lymphoma; lymphoma differential diagnosis
Journal Title:	American Journal of Clinical Pathology
Volume:	164
Issue:	1
ISSN:	0002-9173
Publisher:	Oxford University Press
Date Published:	2025-07-01
Start Page:	85
End Page:	109
Language:	English
DOI:	10.1093/ajcp/aqaf040
PUBMED:	40646681
PROVIDER:	scopus
DOI/URL:	https://www.scopus.com/inward/record.uri?eid=2-s2.0-105010593231&doi=10.1093%2fajcp%2faqaf040&partnerID=40&md5=0f67c2e2d939c200c6be06a249e01932
Notes:	The MSK Cancer Center Support Grant (P30 CA008748) is acknowledge in the PDF -- Corresponding authors is MSK author: Ahmet Dogan -- Source: Scopus

https://synapse.mskcc.org/synapse/works/has_related_data_chk/227171