Large B-Cell Lymphomas in the 5th Edition of the WHO-Classification of Haematolymphoid Neoplasms—Updated Classification and New Concepts

Abstract

The family/class of the large B-cell lymphomas (LBCL) in the 5th edition of the World Health Organization (WHO) classification of haematolymphoid tumors (WHO-HAEM5) features only a few major changes as compared to the 4th edition. In most entities, there are only subtle changes, many of them only representing some minor modifications in diagnostic terms. Major changes have been made in the diffuse large B-cell lymphomas (DLBCL)/high-grade B-cell lymphomas (HGBL) associated with MYC and BCL2 and/or BCL6 rearrangements. This category now consists of MYC and BCL2 rearranged cases exclusively, while the MYC/BCL6 double hit lymphomas now constitute genetic subtypes of DLBCL, not otherwise specified (NOS) or of HGBL, NOS. Other major changes are the conceptual merger of lymphomas arising in immune-privileged sites and the description of LBCL arising in the setting of immune dysregulation/deficiency. In addition, novel findings concerning underlying biological mechanisms in the pathogenesis of the different entities are provided.

Anomaly Detection and Artificial Intelligence Identified the Pathogenic Role of Apoptosis and RELB Proto-Oncogene, NF-kB Subunit in Diffuse Large B-Cell Lymphoma

“…The diagnostic criteria of DLBCL are heterogeneous and include several subtypes such as T cell/histiocyte-rich large B cell lymphoma, the primary DLBCL of the mediastinum, intravascular large B cell lymphoma, lymphomatoid granulomatosis, the primary DLBCL of the central nervous system, the primary cutaneous DLBCL leg type, DLBCL associated with chronic inflammation, and Epstein-Barr virus-positive (EBER)-positive DLBCL. In the WHO classification, other categories are included [1,2,5], which have features of overlap between DLBCL and other subtypes (Burkitt lymphoma), such as high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements and high-grade B-cell lymphoma not otherwise specified [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32].…”

Promising immunotherapeutic approaches for primary effusion lymphoma

“…As for the differential diagnosis, there exist neoplasms featuring serious effusion such as diffuse large cell lymphoma and Burkitt’s lymphoma with effusion [ 17 ]. Recently classified HHV8 negative PEL-like lymphoma shows similar clinical and pathological features (lymphomatous effusion without detectable mass), except for being not infected HHB8/KSHV and CD20 positive, termed “HHV8/KSHV negative effusion-based lymphoma” was proposed as another category of lymphoma [ 18 , 19 ]. Immunohistochemical staining of HHV8 LANA-1 is used for the diagnosis of PEL.…”

EBV Positive Diffuse Large B Cell Lymphoma with Negative Pan‐B Cell Markers, Case Report, and Literature Review

“…B cell lymphomas that are nonetheless typically negative for traditional pan-B cell markers have been observed and well characterized, including ALK positive large B cell lymphoma, primary effusion lymphoma, plasmablastic lymphoma, HHV8+ large B cell lymphoma, and unclassifiable large B cell lymphoma [ 6 – 9 ], Table 1 .…”