Large B-cell lymphoma classification has changed significantly over the decades, evolving from a purely morphologic categorization to one using sophisticated ancillary studies including molecular analysis, immunohistochemistry, and cytogenetics, in addition to morphology and clinical presentation.
To discuss and interpret the key ancillary studies required for subclassification in 2019 and review the differential diagnosis of diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS).
Recent literature on the subcategories of large B-cell lymphoma is reviewed, along with relevant updates from the 2016 , with an emphasis on Epstein-Barr virus-positive lymphoproliferative disorders, high-grade B-cell lymphoma with and and/or rearrangements, and large B-cell lymphoma with rearrangement.
Cases with DLBCL, NOS histology can be further subclassified on the basis of cell of origin studies, Epstein-Barr virus-encoded small RNAs, and and/or rearrangement studies, and other relevant cytogenetic and immunohistochemical studies. The diagnosis of DLBCL, NOS is therefore a diagnosis of exclusion.