Plasmablastic lymphoma (PBL) is an uncommon yet aggressive subtype of non-Hodgkin lymphoma. This cancer originates from B-cells that transform, developing characteristics similar to plasma cells, which generate antibodies. While PBL shares features with plasma cell disorders, it is a distinct condition and should not be confused with multiple myeloma.
Associated Conditions and Risk Factors
Plasmablastic lymphoma is strongly linked to conditions that weaken the body’s immune system, known as immunosuppression. It is strongly associated with Human Immunodeficiency Virus (HIV) infection, recognized as an AIDS-defining illness and accounting for a notable percentage of lymphomas in individuals with HIV.
Other forms of immunosuppression also increase the risk of PBL. This includes organ transplant recipients taking medications to prevent rejection. Certain autoimmune diseases can also raise the risk. The Epstein-Barr virus (EBV) is frequently detected in PBL cases, suggesting its involvement in the disease’s development.
Symptoms and Common Locations
Plasmablastic lymphoma manifests as a fast-growing tumor. The most frequent location for these tumors is within the oral cavity, affecting the jaw, gums, or palate. These oral lesions may present as a lump or sore, sometimes bleeding.
While the oral cavity is a common site, PBL can also appear in other parts of the body, including:
Gastrointestinal tract
Skin
Bone
Lymph nodes
Central nervous system
Nasal cavities
Genitourinary tract
Liver
Lung
Orbits
Individuals with aggressive lymphomas like PBL may also experience systemic “B symptoms”: unexplained fevers, drenching night sweats, and significant, unintentional weight loss.
The Diagnostic Process
Diagnosing plasmablastic lymphoma begins with a physical examination and a review of the patient’s medical history. The definitive step in confirming a PBL diagnosis involves obtaining a tissue sample through a biopsy. This sample is then sent to a pathology laboratory for microscopic examination.
A pathologist analyzes the cells from the biopsy, looking for their characteristic appearance and performing specific tests. Immunohistochemistry is a technique used to identify protein markers present on the surface of the cancer cells. For PBL, cells express plasma cell markers such as CD138 and MUM1, while lacking the CD20 and PAX5 markers commonly found on other B-cell lymphomas. After the diagnosis is confirmed, imaging tests like computed tomography (CT) and positron emission tomography (PET) scans are performed to determine the extent of the cancer’s spread, a process known as staging.
Treatment Approaches
Plasmablastic lymphoma necessitates intensive treatment strategies. Multi-agent chemotherapy regimens are the primary approach to combat this cancer. Common intensive chemotherapy protocols include dose-adjusted EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin), CODOX-M/IVAC (cyclophosphamide, vincristine, doxorubicin, and high-dose methotrexate alternated with ifosfamide, etoposide, and high-dose cytarabine), or Hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternated with high-dose methotrexate and cytarabine). These regimens aim to destroy the rapidly dividing cancer cells throughout the body.
A particularly important aspect of treatment for individuals with underlying immunosuppression, especially HIV, involves managing that condition concurrently. For HIV-positive patients, highly active antiretroviral therapy (HAART) is administered alongside chemotherapy to control the viral infection and improve immune function. This integrated approach is beneficial for treatment outcomes. In select patients who demonstrate a good response to initial chemotherapy, consolidation therapy with an autologous stem cell transplant may be considered to further reduce the risk of relapse.
Prognosis and Survival Factors
Plasmablastic lymphoma is an aggressive cancer with a historically challenging prognosis. The outlook for individuals with PBL can vary, with median survival times often ranging from approximately 8 to 15 months, though outcomes are improving with modern aggressive treatments. Several factors influence an individual’s prognosis.
The patient’s HIV status and how well their HIV infection is controlled with antiretroviral therapy can impact survival. The stage of the cancer at diagnosis, indicating how widely it has spread, also plays a role, with limited-stage disease often having a better outlook than advanced stages. An individual’s overall health and their ability to tolerate intensive treatments are also important considerations. How effectively the cancer responds to the initial chemotherapy regimen is a strong predictor of long-term outcomes. Research into new therapeutic approaches for PBL remains ongoing, aiming to further improve outcomes for patients.