Emerging entities: high-grade/large B-cell lymphoma with 11q aberration, large B-cell lymphoma with IRF4 rearrangement, and new molecular subgroups in large B-cell lymphomas: a report of the 2022 EA4HP/SH lymphoma workshop.
Leticia Quintanilla-FendCamille LaurentLorinda SomaSiok Bian NgFina ClimentSarah L OndrejkaAlberto ZamoAndrew WotherspoonLaurence L de LevalStefan DirnhoferLorenzo LeonciniPublished in: Virchows Archiv : an international journal of pathology (2023)
Emerging entities and molecular subgroups in large B-cell lymphomas (LBCLs) were discussed during the 2022 European Association for Haematopathology/Society for Hematopathology workshop in Florence, Italy. This session focused on newly recognized diseases and their diagnostic challenges. High-grade/large B-cell lymphoma with 11q aberration (HG/LBCL-11q) is defined by chromosome 11q-gains and telomeric loss. FISH analysis is recommended for the diagnosis. HG/LBCL-11q can occur in the setting of immunodeficiency, including ataxia-telangiectasia, and predominates in children. The morphological spectrum of these cases is broader than previously thought with often Burkitt-like morphology and coarse apoptotic bodies. It has a Burkitt-like immunophenotype (CD10+, BCL6+, BCL2-) but MYC expression is weak or negative, lacks MYC rearrangement, and is in contrast to Burkitt lymphoma 50% of the cases express LMO2. LBCL with IRF4 rearrangement (LBCL-IRF4) occurs mainly in the pediatric population but also in adults. LBCL-IRF4 has an excellent prognosis, with distinguishing molecular findings. IRF4 rearrangements, although characteristic of this entity, are not specific and can be found in association with other chromosomal translocations in other large B-cell lymphomas. Other molecular subgroups discussed included primary bone diffuse large B-cell lymphoma (PB-DLBCL), which has distinctive clinical presentation and molecular findings, and B-acute lymphoblastic leukemia (B-ALL) with IGH::MYC translocation recently segregated from Burkitt lymphoma with TdT expression. This latter disorder has molecular features of precursor B-cells, often tetrasomy 1q and recurrent NRAS and KRAS mutations. In this report, novel findings, recommendations for diagnosis, open questions, and diagnostic challenges raised by the cases submitted to the workshop will be discussed.
Keyphrases
- diffuse large b cell lymphoma
- high grade
- epstein barr virus
- acute lymphoblastic leukemia
- dendritic cells
- single molecule
- low grade
- cell death
- transcription factor
- minimally invasive
- heavy metals
- dna methylation
- oxidative stress
- magnetic resonance
- magnetic resonance imaging
- dna damage
- acute myeloid leukemia
- clinical practice
- immune response
- young adults
- risk assessment
- early onset
- working memory
- molecular dynamics
- bone mineral density
- fluorescent probe
- nk cells