B-cell lymphoma is a cancer that starts in B lymphocytes, a type of white blood cell responsible for making antibodies to fight infections. It accounts for about 85% of all non-Hodgkin lymphomas in the United States, making it the most common category of lymphatic cancer. The disease develops when genetic errors cause B cells to grow uncontrollably, forming tumors most often in lymph nodes but potentially in almost any organ.
How Normal B Cells Become Cancerous
B cells go through a complex maturation process that involves rewriting portions of their own DNA. This is normal and necessary for producing effective antibodies. But the same machinery that edits B-cell DNA can misfire, creating genetic damage that leads to cancer.
One key player is a protein that helps B cells diversify their antibodies by intentionally cutting and rearranging DNA. When this protein acts on the wrong genes, it can cause chromosomal translocations, where pieces of two different chromosomes swap places. A well-known example is the t(14;18) translocation found in many follicular lymphomas, which places a survival gene next to an always-on switch, making the cell resist normal death signals. Similar rearrangements involving the MYC gene drive more aggressive lymphomas like Burkitt lymphoma.
Beyond translocations, B-cell lymphomas accumulate other genetic damage. Mutations in tumor suppressor genes like TP53 disable the cell’s ability to stop dividing when something goes wrong. Over 50% of diffuse large B-cell lymphoma cases show widespread mutations introduced by the same DNA-editing machinery that normally fine-tunes antibodies. These mutations can activate growth-promoting genes or silence protective ones, pushing the cell further toward uncontrolled growth.
Major Subtypes
B-cell lymphoma isn’t a single disease. It includes more than a dozen subtypes that behave very differently, from slow-growing cancers that may not need treatment for years to aggressive forms that require immediate intervention.
- Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive type, making up roughly one-third of all non-Hodgkin lymphomas. It grows quickly and typically presents as a rapidly enlarging mass.
- Follicular lymphoma is the most common slow-growing (indolent) type. It often progresses over years and may be monitored without treatment initially.
- Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) involves the same cancer cell seen in blood (CLL) or primarily in lymph nodes (SLL). It tends to be slow-growing.
- Mantle cell lymphoma is less common and often behaves aggressively, though some cases follow a more indolent course.
- Marginal zone lymphomas can arise in lymph nodes, the spleen, or other organs. Some forms are linked to chronic infections or autoimmune conditions.
- Burkitt lymphoma is one of the fastest-growing human cancers. It is strongly associated with Epstein-Barr virus in some regions of the world.
Other less common subtypes include lymphoplasmacytic lymphoma (also called Waldenström macroglobulinemia), hairy cell leukemia, and primary central nervous system lymphoma.
Symptoms to Recognize
The most common first sign is a painless, swollen lymph node, usually in the neck, armpit, or groin. Because swollen lymph nodes are common with ordinary infections, many people don’t seek medical attention immediately. The difference with lymphoma is that the swelling persists and may gradually enlarge over weeks.
Doctors also look for a specific set of warning signs called B symptoms, which signal more active disease. These are: unexplained fever above 100.4°F (38°C), drenching night sweats that soak through clothing or bedding, and unexplained weight loss of more than 10% of body weight within six months. Not everyone with B-cell lymphoma develops these symptoms, but their presence affects how the disease is staged and treated.
Other symptoms depend on where the lymphoma is growing. Tumors in the chest can cause coughing or shortness of breath. Lymphoma in the abdomen may cause bloating, pain, or a feeling of fullness. Fatigue and persistent itching are also common.
What Increases Your Risk
Most people diagnosed with B-cell lymphoma have no single identifiable cause, but several factors raise the odds. A weakened immune system is one of the strongest risk factors. This includes people taking immunosuppressive medications after organ transplants as well as those with HIV.
Certain autoimmune conditions also increase risk, including Hashimoto disease, Sjögren syndrome, rheumatoid arthritis, and lupus. The chronic immune stimulation in these conditions may drive B cells to divide more frequently, increasing the chance of genetic errors.
Specific infections have been linked to particular subtypes. Epstein-Barr virus is associated with Burkitt lymphoma and some cases of DLBCL. Hepatitis C is linked to certain marginal zone lymphomas, and the stomach bacterium H. pylori can trigger a type of marginal zone lymphoma in the stomach lining.
How It Is Diagnosed
A definitive lymphoma diagnosis requires a biopsy, and the type of biopsy matters significantly. A fine-needle aspiration, which extracts only scattered cells through a thin needle, is almost never sufficient for an initial lymphoma diagnosis because it can’t show how cells are arranged within the lymph node. That architectural pattern is essential for identifying the subtype.
The preferred approach is an excisional biopsy, where a surgeon removes an entire lymph node or a large portion of tissue. This gives pathologists enough material to examine the tissue structure, run specialized stains, and perform genetic testing to identify the specific subtype and its driving mutations.
Once a diagnosis is confirmed, imaging scans (most commonly PET-CT) are used to determine how far the disease has spread. B-cell lymphoma is staged using a four-stage system based on where tumors are found in the body:
- Stage I: Cancer in one lymph node region or one organ outside the lymphatic system.
- Stage II: Cancer in two or more lymph node regions on the same side of the diaphragm (the muscle separating the chest from the abdomen).
- Stage III: Cancer in lymph node regions on both sides of the diaphragm, or involving the spleen.
- Stage IV: Cancer has spread widely to organs outside the lymphatic system, such as the bone marrow, liver, or lungs.
Importantly, even advanced-stage lymphoma is often treatable. Unlike many solid-tumor cancers, stage IV lymphoma does not automatically mean a poor prognosis.
Treatment Approaches
Treatment depends heavily on the subtype and stage. For aggressive lymphomas like DLBCL, a combination regimen called R-CHOP has been a standard for over two decades. It combines a targeted therapy (rituximab) with three chemotherapy drugs (cyclophosphamide, doxorubicin, and vincristine) plus the steroid prednisone. The rituximab component locks onto a protein called CD20 found on the surface of B cells, flagging them for destruction by the immune system. A typical course runs six cycles, each spaced about three weeks apart.
For slow-growing lymphomas like follicular lymphoma, treatment may not begin immediately. A strategy called watchful waiting involves regular monitoring with scans and blood work, starting treatment only when symptoms develop or the disease shows signs of progressing. When treatment is needed, it often involves rituximab alone or combined with milder chemotherapy.
For people whose lymphoma returns after initial treatment or doesn’t respond to it, newer therapies have transformed the outlook. As of early 2025, four CAR-T cell therapies targeting the CD19 protein on B cells have received FDA approval for various B-cell lymphomas. In this approach, a patient’s own immune cells are collected, genetically engineered in a lab to recognize and attack lymphoma cells, then infused back into the body. Three bispecific antibody treatments targeting CD20 are also now approved, offering an off-the-shelf alternative that doesn’t require the weeks of manufacturing time that CAR-T therapy needs.
Survival and Outlook
Survival rates vary widely by subtype. For DLBCL, the most common aggressive form, the five-year relative survival rate is about 65%, based on data from 2015 to 2021. This number reflects all stages combined, and many patients diagnosed at earlier stages do considerably better. Indolent subtypes like follicular lymphoma generally have higher survival rates, with many patients living well beyond a decade after diagnosis.
These statistics have been improving steadily, driven by rituximab (which revolutionized treatment starting in the late 1990s) and the more recent additions of CAR-T therapy and bispecific antibodies. People diagnosed today, particularly those with access to these newer options if initial treatment fails, face better odds than the historical data reflects.