While cases of PBL may present as a primary oral, or, very rarely a skin or lymph node disease, most individuals present with a widespread stage III or IV disease which in ~40% of cases, is accompanied by systemic B-symptoms such as fever, night sweats, and recent weight loss. Some 48%-63% of PBL cases occur in individuals with HIV/AIDS; ~80% of these HIV/AIDS-afflicted individuals have EBV+ disease whereas only ~50% of PBL individuals that do not have HIV/AIDS are EBV-positive. Individuals who develop PBL following organ transplantation are EBV-positive in >85% of cases. Most post-transplant and HIV/AIDS patients have an extremely aggressive disease. However, patients whose major contributing factor to PBL-development is EBV-positivity often present with, and continue to have, a significantly less aggressive disease than other patients with PBL. It is similarly clear that, on average, elderly patients (>68 years) likewise present with, and continue to have, a significantly less aggressive cancer. Pathophysiology
In addition to the immunodeficiency-causing viral disease, HIV/AIDS (which is an AIDS-defining clinical condition), recent studies have diagnosed PBL in individuals who have one or more other causes for immunodeficiency. These causes include prior organ transplantation; immunosuppressive drugs; autoimmune and chronic inflammatory diseases (e.g. hepatitis C, rheumatoid arthritis, Graves disease, Giant-cell arteritis, sarcoidosis, and severe psoriasis); and immunosenescence due to age (e.g. >60 years). Rare cases of PDL have also occurred as a transformation of a low grade B-cell malignancy such as chronic lymphocytic leukemia/small lymphocytic lymphoma and follicular lymphoma.
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.