The presence of HIV/AIDS or other causes of immuno-incompetence (see previous section), a history of having a low-grade lymphoma, and/or the presence of EVB+ plasmablasts in the diseases lesions would support the diagnosis of PBL. Differential diagnosis
Various lymphomas can exhibit the microscopic appearance, including plasmablastic cells, and presentation of PBL. These lymphomas can usually be differentiated from PBL by further examinations of the plasmablasts for various marker proteins and determining other factors that favor the diagnosis of these lymphomas rather than PBL, as indicated in the following descriptions. Anaplastic lymphoma kinase-positive large B-cell lymphoma
Unlike PBL, the plasmablastic cells in anaplastic lymphoma kinase-positive large B-cell lymphoma strongly express the product of the ACVRL1 gene, i.e. activin receptor-like kinase 1 (ALK1) and are not infected with EBV and therefore do not express this viruss EBER or BART RNAs. Human herpesvirus 8-positive diffuse large B-cell lymphoma, not otherwise specified
Unlike PBL, the plasmablastic cells in human herpesvirus 8-positive diffuse large B-cell lymphoma, not otherwise specified express products of herpesvirus 8 (also termed Karposi sarcoma virus) such as LANA-1 protein. Also unlike PBL, these plasmablastic cells do not express CD30, CD138, CD79a, or a clonal IgM antibody and usually are not EBV-infected and therefore usually do not express this viruss EBER or BART RNAs. Primary effusion lymphoma
In contrast to PBL, the plasmablastic cells in primary effusion lymphomas, whether HHV8-positive or HHV8-negative, usually strongly express CD45 and in HHV8 cases express HHV8 proteins such as the LANA-1 protein.
In 2017, this Organization classified PBL as the most common member of a rare subgroup of lymphomas termed lymphoid neoplasms with plasmablastic differentiation. See also
Lymphoma
Epstein–Barr virus–associated lymphoproliferative diseases

References

Category:Lymphoid-related cutaneous conditions