A recently developed diagnostic category for aggressive B-cell lymphomas is high-grade B-cell lymphoma (HGBL), not otherwise specified (NOS). It contains tumors that lack double-hit cytogenetics and exhibit Burkitt-like or blastoid shape but cannot be categorized as another well-defined lymphoma subtype.
Rare and diverse, HBCLs, NOS, have a germinal center B-cell phenotype in the majority of cases, and up to 45% of them exhibit a single-hit MYC rearrangement, but they lack any defining immunophenotypic or cytogenetic traits. Recent research employing gene expression profiling (GEP) found that up to 15% of tumors now categorized as diffuse large B-cell lymphoma have an HGBL-like GEP signature, indicating a possibility to extend the HGBL category using more objective molecular criteria greatly. Because of its rarity and variable diagnostic patterns, the ideal course of treatment for HGBL, NOS, was not well understood.
Only a small percentage of patients have an early-stage illness, which can be treated with conventional R-CHOP-based methods with or without radiation treatment. Intensified Burkitt lymphoma-like regimens with CNS prophylaxis may be suitable for advanced-stage HGBL, NOS, which frequently exhibits aggressive disseminated disease, elevated lactate dehydrogenase, and involvement of extranodal organs (including the central nervous system [CNS]). However, many individuals more than 60 who receive a diagnosis are ineligible for rigorous immunochemotherapy.
To enhance outcomes for all patients, a better GEP- and/or genomic-based pathologic categorization that might permit HGBL-specific studies is required.