IRF4 translocation status in pediatric follicular and diffuse large B-cell lymphoma patients enrolled in Children’s Oncology Group trials

Chisholm KM, Mohlman J, Liew M, Termuhlen A, Cairo MS, Gross TG, Perkins SL, Miles RR. IRF4 translocation status in pediatric follicular and diffuse large B-cell lymphoma patients enrolled in Children’s Oncology Group trials. Pediatr Blood Cancer. 2019 Aug;66(8):e27770. doi: 10.1002/pbc.27770. Epub 2019 Apr 22. PubMed PMID: 31012208; PubMed Central PMCID: PMC6941672.

Large B-cell lymphoma with IRF4 rearrangement is a provisional entity in the 2017 World Health Organization classification. In order to characterize these lymphomas in children from the United States, IRF4 fluorescence in situ hybridization and immunohistochemical stains were performed on 32 follicular (FL) and diffuse large B-cell lymphomas (DLBCL) from Children’s Oncology Group studies. Two DLBCLs (6%) had IRF4 rearrangements, one involving the ileocecal valve and another involving the tonsil and cerebrospinal fluid. Both cases had strong, diffuse IRF4/MUM1 immunohistochemical staining, which may be a pathologic clue to the diagnosis. Reclassification of these cases may have prognostic and therapeutic implications.