Plasmablastic lymphoma is a rare and aggressive form of cancer affecting white blood cells, most commonly appearing in people with weakened immune systems, particularly those living with HIV. Despite advances in cancer treatment, this disease continues to present significant challenges in both diagnosis and management.
Understanding Plasmablastic Lymphoma
Plasmablastic lymphoma, often shortened to PBL, is an uncommon but highly aggressive type of cancer that falls under the broader category of diffuse large B-cell lymphoma. This means it starts in a specific type of white blood cell called B-cells, which normally help your body fight infections by producing antibodies. In plasmablastic lymphoma, these cells undergo an unusual transformation. Instead of maturing properly, they become stuck in an intermediate stage called plasmablasts, which are cells that appear somewhere between regular B-cells and plasma cells. These abnormal cells then multiply uncontrollably and accumulate in various parts of the body.[1]
The disease was first identified and described in 1997 by a researcher named Delecluse, who studied 16 patients with a distinctive type of lymphoma affecting the mouth. Remarkably, 15 of these 16 patients were living with HIV, which immediately suggested a strong connection between this cancer and immune system problems.[4] Since then, medical professionals have recognized plasmablastic lymphoma as a distinct disease entity, though it remains relatively rare and continues to pose significant challenges for healthcare providers trying to diagnose and treat it effectively.
What makes plasmablastic lymphoma particularly distinctive is that the cancer cells look similar to other types of large B-cell cancers under the microscope, but they behave more like plasma cells when tested with special markers. This unusual characteristic is what gives the disease its name and also makes it harder to diagnose correctly, as it can be confused with other types of blood cancers.[1]
Epidemiology: Who Gets Plasmablastic Lymphoma?
Plasmablastic lymphoma is genuinely rare in the overall population. Among people living with HIV who develop lymphomas, plasmablastic lymphoma accounts for only about 2 percent of all cases. This means that even within a group already at higher risk, the disease is uncommon.[2] However, understanding who is most likely to develop this condition helps both patients and healthcare providers stay vigilant.
The disease shows a strong preference for males. Studies have found that approximately 73 percent of all plasmablastic lymphoma cases occur in men, making it significantly more common in males than females.[3] Additionally, another report found that about 3 out of 4 people diagnosed with this lymphoma are men.[2] This gender difference is particularly pronounced in people who are HIV-positive, where males predominate. Interestingly, in the HIV-negative population, some studies have noted a different pattern, with more females being affected, though the overall numbers remain small.[11]
Age-wise, plasmablastic lymphoma typically affects middle-aged and older adults. One comprehensive review of published cases found that patients ranged in age from 1 to 88 years, with a median age of 58 years at diagnosis.[3] While the disease can technically occur at any age, it is quite rare in children and when it does appear in younger patients, it is usually in the context of HIV infection.[11]
The connection between plasmablastic lymphoma and HIV is one of the most striking epidemiological features of this disease. Research indicates that roughly half to two-thirds of all people diagnosed with plasmablastic lymphoma are HIV-positive. A large study conducted in the United States found that 69 percent of plasmablastic lymphoma patients had HIV infection.[11] This strong association means that healthcare providers need to be especially aware of this possibility when examining HIV-positive patients who develop unusual masses or growths.
Causes: What Leads to Plasmablastic Lymphoma?
The exact cause of plasmablastic lymphoma remains unclear, but researchers have identified several factors that appear to play important roles in its development. The most significant factor appears to be chronic viral infections, particularly those that affect the immune system.[11]
The connection between HIV and plasmablastic lymphoma is well-established, though scientists don’t fully understand exactly how HIV contributes to the development of this cancer. HIV is a virus that attacks and weakens the immune system over time, leaving the body vulnerable to various infections and cancers. The immune system normally helps prevent cancer by identifying and destroying abnormal cells before they can multiply and spread. When HIV damages this protective system, it may allow cancer cells to grow unchecked. Additionally, the chronic inflammation and immune activation that occurs with HIV infection may create an environment that favors the development of lymphomas like plasmablastic lymphoma.[11]
Another virus strongly linked to plasmablastic lymphoma is the Epstein-Barr virus, commonly known as EBV. This virus is extremely common in the general population and is best known for causing infectious mononucleosis, often called “mono.” However, EBV has also been implicated in several types of cancer. Studies have found that about 2 out of 3 people with plasmablastic lymphoma show evidence of EBV infection in their cancer cells.[2] EBV appears to cause genetic changes that help B-cells resist normal cell death processes and grow more rapidly than they should, potentially contributing to cancer development.
Importantly, plasmablastic lymphoma doesn’t only occur in people with HIV. The disease has also been documented in people whose immune systems are weakened for other reasons, including those who have received organ transplants and must take immunosuppressive medications to prevent rejection, and those with autoimmune disorders where the immune system attacks the body’s own tissues.[11] About 5 percent of people who develop plasmablastic lymphoma appear to have normally functioning immune systems with no obvious immune deficiency, though this group is small and less well understood.[3]
Risk Factors: Who Is Most Vulnerable?
Understanding the risk factors for plasmablastic lymphoma helps identify who should be most vigilant about potential symptoms and helps healthcare providers make accurate diagnoses. The most significant risk factors all relate to problems with the immune system.
HIV infection stands out as the single strongest risk factor for developing plasmablastic lymphoma. People living with HIV have a substantially increased risk compared to the general population, though the absolute risk remains low given how rare this cancer is overall. The risk appears to be present regardless of how well-controlled the HIV infection is with antiretroviral medications, though maintaining good HIV control and healthy immune function likely provides some protective benefit.[11]
Organ transplant recipients represent another high-risk group. After receiving a kidney, liver, heart, or other organ transplant, patients must take powerful immunosuppressive medications for the rest of their lives to prevent their immune system from rejecting the new organ. These medications intentionally weaken immune function, which unfortunately can allow cancers like plasmablastic lymphoma to develop. The risk appears to be particularly elevated in the first few years after transplantation when immunosuppression is typically strongest.[11]
People with autoimmune disorders who require long-term immunosuppressive treatment also face increased risk. Autoimmune diseases occur when the immune system mistakenly attacks the body’s own healthy tissues. Conditions like rheumatoid arthritis, lupus, and inflammatory bowel disease often require medications that suppress immune function to control symptoms and prevent damage. While these medications are essential for managing the underlying disease, they can increase cancer risk as an unfortunate side effect.[11]
Elderly adults may face a special type of risk even without obvious immune system problems. There is a variant of plasmablastic lymphoma called “plasmablastic lymphoma of the elderly” that occurs in older individuals who don’t have HIV, haven’t had transplants, and don’t have known immune deficiencies. This form of the disease appears to be related to immunosenescence, which is the natural weakening and aging of the immune system that occurs as people get older. Interestingly, this elderly variant tends to have a somewhat better prognosis than plasmablastic lymphoma occurring in younger people or those with HIV.[3]
Chronic infection with Epstein-Barr virus may represent an independent risk factor, though it’s difficult to separate this from other immune system problems since EBV infection is so common in people with weakened immunity. The presence of EBV in cancer cells may also affect prognosis and treatment outcomes.[2]
Symptoms: How Does Plasmablastic Lymphoma Present?
The symptoms of plasmablastic lymphoma depend largely on where in the body the cancer develops. Unlike many other types of lymphoma that primarily affect lymph nodes, plasmablastic lymphoma has a strong tendency to appear in areas outside the lymph node system, a pattern doctors call extranodal disease. This unusual pattern of growth contributes to the diverse symptoms people may experience.[1]
The oral cavity, which includes the mouth, gums, and jaw, is the most common location for plasmablastic lymphoma tumors, accounting for slightly less than half of all cases. When the disease affects the mouth, patients typically notice a lump, mass, or swelling in the jaw or gums. These masses usually grow rapidly over weeks to months. They may feel firm or rubbery to the touch. Some oral tumors cause relatively few symptoms initially, while others may become painful, bleed, or interfere with eating and speaking as they grow larger. In some cases, the growth may look like a sore that doesn’t heal.[2]
The gastrointestinal system is the second most common site of involvement, affected in about 18 percent of cases. When plasmablastic lymphoma develops in the digestive tract, it can affect the stomach, intestines, or other digestive organs. Symptoms may include abdominal pain, which can range from mild discomfort to severe cramping. Some patients experience diarrhea or changes in bowel habits. Blood in the stool is another potential symptom, which may appear bright red or cause stools to look dark and tarry. These symptoms can easily be confused with other gastrointestinal conditions, sometimes leading to delays in diagnosis.[2]
Lymph node involvement occurs in approximately 23 percent of cases. When plasmablastic lymphoma affects lymph nodes, patients notice swollen glands in the neck, armpits, groin, or other areas. These swollen nodes typically feel firm and may or may not be tender. Interestingly, swollen lymph nodes are less common in HIV-positive patients with plasmablastic lymphoma compared to those without HIV. However, about 1 out of 3 people who develop plasmablastic lymphoma after an organ transplant do experience swollen lymph nodes as a presenting symptom.[2]
The bone marrow, which is the soft, spongy tissue inside bones where blood cells are made, is involved in about 16 percent of cases. When plasmablastic lymphoma spreads to the bone marrow, it can interfere with normal blood cell production, potentially causing anemia (low red blood cells), increased infections due to low white blood cells, or easy bruising and bleeding due to low platelets.[3]
Skin involvement is less common overall but appears to be more frequent in people who have had organ transplants. When plasmablastic lymphoma affects the skin, it typically appears as lumps or growths underneath the skin’s surface. These may look like raised bumps or nodules and can occur anywhere on the body.[2]
The nose and sinuses can also be affected, leading to symptoms such as nosebleeds, persistent runny nose, sinus pressure or pain, or congestion that doesn’t improve with typical treatments. Less commonly, the disease can affect the lungs, bones, or genitourinary tract, causing symptoms related to those specific areas.[3]
Some people with plasmablastic lymphoma experience what doctors call “B symptoms,” which are a specific set of constitutional symptoms that indicate more aggressive or widespread disease. B symptoms include drenching night sweats that soak through bedclothes and sheets, fevers without any obvious infection, and unintentional weight loss of 10 percent or more of body weight over six months. These symptoms are more common in people with HIV infection than in those without it.[2]
Most people with plasmablastic lymphoma present with advanced stage disease, meaning the cancer has already spread to multiple areas of the body by the time it’s diagnosed. In fact, most patients are diagnosed with stage III or IV disease, which is the most advanced staging. About 40 percent of people have B symptoms at diagnosis, indicating widespread or aggressive disease.[3]
Prevention: Can Plasmablastic Lymphoma Be Prevented?
Because the exact causes of plasmablastic lymphoma are not fully understood and the disease appears to be closely tied to immune system function, there are no proven strategies to completely prevent it. However, several approaches may help reduce risk, particularly in vulnerable populations.
For people living with HIV, maintaining excellent control of the HIV infection through consistent use of antiretroviral therapy (combination medications that suppress HIV) is likely the most important preventive measure. While plasmablastic lymphoma can still occur in people with well-controlled HIV, keeping the immune system as healthy as possible through effective HIV treatment may reduce the overall risk of developing HIV-associated cancers. Regular medical follow-up with an HIV specialist, adherence to prescribed medications, and monitoring of immune function through regular blood tests are all important components of good HIV care that may indirectly help prevent complications like plasmablastic lymphoma.[8]
For organ transplant recipients, the situation is more complicated because immunosuppressive medications are absolutely necessary to prevent organ rejection. However, healthcare providers carefully balance the need for sufficient immunosuppression to protect the transplanted organ against the risks of over-immunosuppression, which increases cancer risk. Regular monitoring and adjustments to immunosuppressive medications by transplant specialists may help minimize cancer risk while still protecting the transplanted organ. Patients should maintain close follow-up with their transplant team and report any unusual symptoms promptly.[11]
Avoiding or minimizing unnecessary immunosuppression in people with autoimmune diseases is another potential preventive approach. Healthcare providers treating autoimmune conditions try to use the lowest effective doses of immunosuppressive medications and may explore alternative treatment approaches when possible. However, controlling the underlying autoimmune disease is critical, so these decisions must be individualized based on each person’s specific situation.
Because Epstein-Barr virus infection is so common and typically occurs in childhood or young adulthood, preventing EBV infection is not generally feasible for most people. There is currently no vaccine available against EBV, though research in this area is ongoing. For people already infected with EBV, which includes most adults worldwide, there is no way to eliminate the virus, as it remains dormant in the body for life.
General health measures that support immune system function may have some benefit, though this has not been specifically studied for plasmablastic lymphoma prevention. These include maintaining a healthy diet rich in fruits, vegetables, and whole grains; getting regular exercise appropriate for one’s health status; getting adequate sleep; managing stress; avoiding tobacco use; and limiting alcohol consumption. While these measures cannot guarantee prevention of plasmablastic lymphoma, they support overall health and may help the immune system function optimally.
Perhaps most importantly, awareness of symptoms and prompt medical attention for unusual lumps, masses, or persistent symptoms can lead to earlier diagnosis and treatment, even if the disease cannot be prevented entirely. People at higher risk, particularly those with HIV, transplant recipients, and those on immunosuppressive medications, should maintain regular medical follow-up and report any concerning symptoms to their healthcare providers without delay.
Pathophysiology: What Happens in the Body?
Understanding what goes wrong in the body during plasmablastic lymphoma helps explain why the disease behaves the way it does and why it’s so challenging to treat. The pathophysiology involves multiple abnormal processes at the cellular and molecular level.
In a normally functioning immune system, B-cells go through an orderly maturation process. When B-cells encounter an infection or foreign substance, they become activated and begin to transform. They progress through several stages, eventually becoming plasma cells, which are the mature cells that produce antibodies to fight infections. During this transformation process, there is a brief intermediate stage where the cells are called plasmablasts. In plasmablastic lymphoma, something goes wrong during this transformation, and the cells become stuck in the plasmablast stage. Instead of maturing properly into plasma cells, they begin dividing uncontrollably while maintaining their plasmablast characteristics.[2]
At the molecular level, plasmablastic lymphoma cells show several important abnormalities. One of the most significant is rearrangement of the MYC gene, which occurs in a substantial proportion of cases. The MYC gene normally controls cell growth and division, but when it becomes rearranged or overactive, it can drive cells to divide much more rapidly than they should. This contributes to the aggressive behavior of plasmablastic lymphoma. MYC rearrangements appear to be more common in cases where Epstein-Barr virus is present in the cancer cells.[5]
Another key feature of plasmablastic lymphoma is the loss of normal B-cell markers on the cell surface. Most B-cell lymphomas express a protein called CD20 on their surface, which serves as both a marker for diagnosis and a target for certain cancer treatments. However, plasmablastic lymphoma cells typically lose CD20 expression and instead express markers more typical of plasma cells, such as CD138 and CD38. This unusual pattern of marker expression is what gives the disease its name and has important implications for treatment, as therapies that target CD20 (like rituximab) are generally not effective for plasmablastic lymphoma.[5]
Studies of gene expression patterns in plasmablastic lymphoma have revealed that these cancer cells show downregulation of normal B-cell receptor signaling pathways. B-cell receptors are proteins on the surface of B-cells that help them recognize foreign substances and coordinate immune responses. In plasmablastic lymphoma, the normal signaling through these receptors is disrupted, which may contribute to the abnormal behavior of the cells.[4]
When Epstein-Barr virus is present in plasmablastic lymphoma cells, it contributes to the disease process through several mechanisms. EBV produces certain proteins that can interfere with normal cell death processes, allowing infected cells to survive longer than they should. The virus can also cause genetic changes that promote cell proliferation and growth. The presence of EBV in the tumor cells can be detected through testing for a marker called EBER, and EBV-positive cases may behave somewhat differently than EBV-negative cases.[5]
The aggressive nature of plasmablastic lymphoma is reflected in its very high growth rate. When pathologists examine plasmablastic lymphoma tissue under the microscope and perform special staining, they typically find that the Ki67 proliferation index (a marker of how rapidly cells are dividing) is very high, often approaching 100 percent. This means nearly all the cancer cells are actively dividing at any given time, which explains why the tumors can grow so rapidly and why the disease tends to spread quickly to multiple sites.[5]
The immune system problems that predispose people to plasmablastic lymphoma also affect how the disease progresses. In people with HIV or other immunodeficiencies, the immune system’s normal ability to recognize and destroy abnormal cells is impaired. This immune surveillance normally helps prevent cancers from developing and spreading. When this protective mechanism is weakened, cancer cells can proliferate more easily and evade detection by immune cells. Additionally, the chronic inflammation that occurs in HIV infection and other immunodeficiency states may create an environment that actually promotes cancer development and progression.
