Since 2022 large B-cell lymphoma with IRF4-rearrangment (LBCL-IRF4+) has been recognized as a definite entity by the World Health Organization (WHO) classification of hematolymphoid tumors. It is characterized by a follicular and/or diffuse growth pattern as well as a strong expression of IRF4, which is due to translocation of IRF4 with an immunoglobulin gene.
Essential and desirable diagnostic criteria are set by the WHO including clinical, morphological, immunophenotypical and molecular- genetic parameters. Given that most LBCL-IRF4+ patients are children and young people, the rarity of this lymphoma and lack of any prospective trials, most data on LBCL-IRF4+ come from small reports.
Thus, two of the largest childhood non-Hodgkin lymphoma (NHL) consortia, the European Intergroup for Childhood NHL (eicnhl) and the international Berlin-Frankfurt-Münster (i-BFM) Group, designed a retrospective multinational study of LBCL-IRF4+ in children and young people. Here we present data from this series, the largest reported to date.