Prognosis
Overall, patients receiving one of the cited chemotherapy regimens have achieved disease-free survival and overall survival rates of 22 and 32 months, respectively. The National Comprehensive Cancer Network recommends the more intensive regimens (e.g. hyper-CVAD-MA or infusional EPOCH) to treat the disease. These regimens have attained 5 year overall and disease-free survivals of 38% and 40%, respectively. Too few patients have been treated with autologous hematopoietic stem cell transplant in addition to chemotherapy for conclusions to be made. A few patients with HIV/AIDS-related PBL disease who were treated with highly active antiretroviral therapy (HAART) directed against the human immunodeficiency virus (i.e. HIV) have had remissions in their PDL lesions. History
A study by Green and Eversole published in 1989 reported on 9 individuals afflicted with HIV/AIDS who
presented with lymphomatous masses in the oral cavity; these lymphomas were populated by apparently malignant Epstein–Barr virus-infected plasmablasts that did not express T-cell lymphocyte marker proteins. Eight years later, Delecluse and colleagues described a lymphoma, which they termed plasmablastic lymphoma, that had some features of a diffuse large B-cell lymphoma but unlike this lymphoma developed exclusively in the oral cavity, consisted of plasmablasts that lacked B-cell as well as T cell marker proteins and, in 15 of 16 cases, were infected with EBV. In 2008, the World Health Organization recognized this lymphoma as a variant of the diffuse large cell lymphomas. Subsequent to this recognition, numerous studies found this lymphoma to occur in a wide range of tissues besides the oral cavity and in individuals with various other predisposing immunodeficiency conditions.
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.