Lymphoma is a cancer that starts in white blood cells called lymphocytes, which are part of your immune system. Unlike cancers that form in organs like the lungs or colon, lymphoma begins in the lymphatic system, a network of vessels, nodes, and tissues that runs throughout your body and helps fight infection. When a lymphocyte’s DNA mutates, the cell begins multiplying out of control, building up in lymph nodes and forming tumors that crowd out healthy tissue.
How Lymphoma Develops
Your body produces two main types of lymphocytes: B cells and T cells. Both play critical roles in identifying and destroying bacteria, viruses, and other threats. Lymphoma occurs when one of these cell types picks up DNA changes that let it grow without the normal checks that keep cell division in balance.
These abnormal lymphocytes accumulate in lymph nodes, which are small, bean-shaped structures clustered in your neck, armpits, groin, chest, and abdomen. Because lymph nodes exist throughout the body, lymphoma cells can collect virtually anywhere. Over time, tumors may also develop in the spleen, bone marrow, or other organs outside the lymphatic system.
Hodgkin vs. Non-Hodgkin Lymphoma
Lymphoma is broadly split into two categories. Hodgkin lymphoma is identified by the presence of a specific abnormal cell visible under a microscope. It tends to follow a more predictable pattern of spread, moving from one group of lymph nodes to neighboring groups. Non-Hodgkin lymphoma is far more common and encompasses dozens of subtypes. The most prevalent is diffuse large B-cell lymphoma, which accounts for roughly 25 to 35% of non-Hodgkin cases in the United States. Follicular lymphoma is the next most common, making up about 20 to 25% of cases.
The distinction matters because each type behaves differently. Some non-Hodgkin subtypes grow slowly over years and may not need immediate treatment, while others are aggressive and require prompt action. Hodgkin lymphoma, though less common, generally responds very well to treatment and has high cure rates even at advanced stages.
Common Symptoms
The most noticeable early sign is a painless, swollen lymph node, usually in the neck, armpit, or groin. Many people discover it while showering or getting dressed. Swollen nodes are extremely common and are usually caused by infections, so a single swollen node doesn’t mean lymphoma. Nodes that persist for weeks without a clear cause, continue to grow, or feel rubbery and fixed in place are the ones that warrant medical attention.
Beyond swollen nodes, doctors look for three specific warning signs known as “B symptoms”: unexplained fevers, drenching night sweats (the kind that soak through your sheets), and unintentional weight loss of more than 10% of your body weight over six months. These symptoms tend to appear more often with aggressive, fast-growing lymphomas. Other possible signs include persistent fatigue, itching without a rash, and feeling full or uncomfortable in the abdomen if the spleen is enlarged.
Risk Factors
Lymphoma is more common in older adults and in men. Having a first-degree relative (parent, sibling, or child) with the disease modestly increases your risk. Several infections are linked to lymphoma, most notably the Epstein-Barr virus, the same virus that causes mononucleosis. HIV and hepatitis B and C also raise the risk.
Conditions that weaken or overstimulate the immune system play a significant role. People who have received organ transplants and take immunosuppressive medications, those living with HIV/AIDS, and people with certain autoimmune diseases like Sjögren’s syndrome, celiac disease, or rheumatoid arthritis all face elevated risk. Environmental exposures, including certain insecticides, have been studied as potential contributors, though these factors are less well established and account for a smaller share of cases.
How Lymphoma Is Diagnosed
Diagnosis typically starts with a physical exam checking for swollen lymph nodes and an enlarged spleen or liver. Blood tests come next. While they can’t always confirm lymphoma on their own, they help by measuring a protein called lactate dehydrogenase (LDH), which tends to be elevated in people with the disease. Blood work also screens for related viral infections like HIV and hepatitis.
The definitive step is a biopsy, usually of a swollen lymph node. A surgeon removes part or all of the node so lab specialists can examine the cells under a microscope, test for specific proteins on the cell surface, and look for DNA changes. These details determine not just whether it’s lymphoma, but which exact subtype, which directly shapes the treatment plan. If lymphoma is confirmed, a bone marrow biopsy (a needle sample taken from the hip bone) and imaging scans help determine how far the disease has spread.
Staging
Lymphoma is staged using a system that focuses on how many lymph node regions are involved and whether the cancer has moved beyond the lymphatic system:
- Stage I: Cancer is in a single lymph node region or a single organ outside the lymphatic system.
- Stage II: Two or more lymph node regions are affected, but all are on the same side of the diaphragm (the muscle that separates the chest from the abdomen).
- Stage III: Lymph node regions on both sides of the diaphragm are involved, possibly including the spleen.
- Stage IV: The cancer has spread widely into organs outside the lymphatic system, such as the liver, bone marrow, lungs, or cerebrospinal fluid.
A letter “B” is added to any stage if the patient has B symptoms (fever, night sweats, weight loss), and an “A” if those symptoms are absent. This letter designation affects prognosis and treatment decisions.
Treatment Options
Treatment depends heavily on the specific subtype, the stage, and how quickly the lymphoma is growing. Slow-growing (indolent) lymphomas that aren’t causing symptoms are sometimes monitored with regular checkups rather than treated immediately, an approach called watchful waiting. Aggressive lymphomas are treated right away, most often with combination chemotherapy, sometimes paired with radiation targeting specific lymph node regions.
For lymphomas that come back after initial treatment or don’t respond to it, stem cell transplants are an option. This involves using high-dose chemotherapy to destroy the diseased bone marrow, then replacing it with healthy stem cells from the patient’s own body or a donor.
One of the most significant advances in recent years is CAR T-cell therapy, a form of immunotherapy. In this approach, a patient’s own immune cells are removed, genetically reprogrammed in a lab to recognize and attack lymphoma cells, then infused back into the body. The FDA first approved a CAR T-cell therapy in 2017, and several are now available for different forms of non-Hodgkin lymphoma. In a clinical trial involving people with advanced follicular lymphoma, one CAR T-cell therapy eliminated cancer in nearly 80% of patients, with many still cancer-free three years later. For large cell lymphoma, the most common form, more than 30% of participants in trials were alive with no detectable cancer five years after treatment. CAR T-cell therapies are increasingly being used earlier in the treatment process rather than as a last resort.
Survival Rates
Survival has improved substantially over the past few decades. Based on data from 2016 to 2022, the overall five-year relative survival rate for non-Hodgkin lymphoma is about 74%. That number varies by stage: 87.6% for stage I, 79.7% for stage II, 74% for stage III, and 63.6% for stage IV. Hodgkin lymphoma generally has even higher survival rates, particularly in younger patients.
These statistics represent averages across all subtypes and age groups. Individual outcomes depend heavily on the specific type of lymphoma, how well it responds to treatment, and the patient’s overall health. Some subtypes, like follicular lymphoma, can be managed for many years even when a complete cure isn’t achieved. Others, like diffuse large B-cell lymphoma, are aggressive but highly curable with the right combination of therapies.