Epstein–Barr virus positive diffuse large B-cell lymphoma, not otherwise specified (EBV+ DLBCL, NOS) is a form of diffuse large B-cell lymphomas (DLBCL) accounting for around 10-15% of DLBCL cases. DLBCL are lymphomas in which B-celllymphocytes proliferate excessively, invade multiple tissues, and often causes life-threatening tissue damage. EBV+ DLBCL is distinguished from DLBCL in that virtually all the large B cells in the tissue, infiltrates of the Epstien-Barr virus (EBV) express EBV genes characteristic of the virus's latency III (common in the elderly) or II (common in younger patients) phase.[2] EBV is a ubiquitous virus, infecting around 95% of the world population.
EBV+ DLBCL, NOS was previously named Epstein–Barr virus-positive DLBCL of the elderly, by the World Health Organization (WHO) in 2008; because it appeared to be limited to people over the age of 50.[3][4]: 369–370 [5] The name was changed to EBV+ DLBCL, NOS by the WHO in 2016, after the disease was described in much younger adults and children.[6][7] The disease is also classified as one of numerous related and interrelated Epstein-Barr virus-associated lymphoproliferative diseases.[6] EBV+ DLBCL, NOS is usually CD20 positive, and has clonal immunoglobulin gene rearrangement.[4]: 380
Biology
Although reported almost exclusively in Asians, it is not confined to that population.[4]: 369 [8] The disease usually has an extranodal presentation, with or without lymph node involvement.[4]: 369
Morphologically, areas of necrosis are often seen[4]: 370 [5] as well as Reed–Sternberg-like cells.[4]: 370 [5] There are two subtypes: one with monotonous large cells, the other with numerous cell sizes as well as reactive cells, but different clinical behavior is not appreciated between these subtypes.[4]: 370 Morphological differential diagnosis is Hodgkin lymphoma.[4]: 370 Median survival is 2 years in the elderly.[4]: 369
