Lymphoma is a cancer that starts in white blood cells called lymphocytes, which are part of your immune system. Unlike cancers that form in a single organ, lymphoma originates in cells that travel throughout your body, meaning it can develop almost anywhere, though it most commonly shows up as swollen lymph nodes. It is broadly divided into two main types: Hodgkin lymphoma and non-Hodgkin lymphoma.
How Lymphoma Develops
Your lymphocytes are infection-fighting cells that normally grow, divide, and die on a predictable schedule. Lymphoma begins when DNA changes in one of these cells override that schedule. The altered cell multiplies rapidly and doesn’t die when it should, producing a growing population of abnormal lymphocytes that crowd out healthy tissue.
These cancerous cells tend to collect in lymph nodes, the small bean-shaped structures scattered throughout your neck, armpits, groin, chest, and abdomen. But because lymphocytes circulate through your blood and lymphatic fluid, the disease can also build up in the bone marrow, spleen, and other organs, limiting their ability to function normally.
Hodgkin vs. Non-Hodgkin Lymphoma
The distinction between the two main types comes down to what the cancer cells look like under a microscope. If a pathologist finds a specific abnormal cell called a Reed-Sternberg cell, the diagnosis is Hodgkin lymphoma. If that cell isn’t present, it’s classified as non-Hodgkin lymphoma.
Non-Hodgkin lymphoma is far more common and includes dozens of subtypes. Most arise from B cells, one of the two main classes of lymphocytes. The most frequently diagnosed subtypes include diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, mantle cell lymphoma, and Burkitt lymphoma. A smaller share involves T cells, the other class of lymphocyte, and includes peripheral T-cell lymphoma and cutaneous T-cell lymphoma.
Indolent vs. Aggressive Types
Beyond the Hodgkin/non-Hodgkin split, doctors also classify lymphomas by how fast they grow. This distinction shapes what treatment looks like and when it needs to start.
Indolent (low-grade) lymphomas grow slowly. Some patients live for years without needing any treatment at all, instead following a “watch and wait” approach with regular monitoring. Follicular lymphoma, marginal zone lymphoma, and chronic lymphocytic leukemia/small lymphocytic lymphoma all fall into this category.
Aggressive (high-grade) lymphomas progress rapidly and require prompt, intensive treatment. DLBCL, Burkitt lymphoma, and peripheral T-cell lymphoma are common examples. Hodgkin lymphoma is also generally classified as aggressive. The tradeoff is that aggressive lymphomas, because their cells are dividing quickly, often respond well to treatments designed to kill fast-growing cells.
Symptoms to Recognize
The most noticeable early sign is one or more swollen lymph nodes, typically painless, in the neck, armpit, or groin. But lymphoma also produces a set of whole-body symptoms that doctors specifically track, known as “B symptoms”:
- Unexplained fevers above 100.4°F (38°C)
- Drenching night sweats severe enough to soak through your bedclothes
- Unexplained weight loss of more than 10% of your body weight within six months
Not everyone with lymphoma develops B symptoms, but their presence signals that the disease is having a systemic effect on the body. Other common complaints include persistent fatigue, itching, and feeling full quickly due to an enlarged spleen pressing on the stomach.
What Raises Your Risk
Several factors increase the likelihood of developing lymphoma. A weakened or overactive immune system tops the list. People with HIV have a higher risk, partly because the virus itself compromises immune surveillance and partly because it interacts with other viruses linked to lymphoma.
Certain infections play a direct role. The Epstein-Barr virus (the same virus that causes mono) is an important risk factor for Burkitt lymphoma, particularly in parts of Africa, and is linked to several rarer subtypes in developed countries. Human T-cell lymphotropic virus (HTLV-1) raises the risk of specific T-cell lymphomas, though it accounts for less than 1% of lymphomas in the United States. Human herpesvirus 8 can infect lymphocytes and lead to a rare type called primary effusion lymphoma.
Autoimmune diseases like rheumatoid arthritis, lupus, and celiac disease are also associated with increased risk. The theory is straightforward: when the immune system is chronically overactive, lymphocytes divide more frequently than normal, raising the odds that one will develop a cancerous mutation.
How Lymphoma Is Diagnosed
A biopsy of an enlarged lymph node is the cornerstone of diagnosis. Doctors generally prefer a surgical excision biopsy, where an entire lymph node is removed and examined. This gives pathologists a much larger tissue sample to work with, making it easier to evaluate the architecture of the cells and identify the exact subtype. In a large study reviewed by the American Society of Hematology, surgical excision produced a definitive diagnosis 98.1% of the time, compared to 92.3% for core needle biopsy.
Getting the subtype right matters because treatment varies significantly between subtypes. Some lymphomas, particularly certain T-cell types and Hodgkin lymphoma, are especially hard to diagnose from a small needle sample because pathologists need to see how cells are arranged within the tissue, not just what individual cells look like. When a needle biopsy leaves any uncertainty, the standard recommendation is to follow up with a full surgical excision.
Staging
Once lymphoma is confirmed, doctors determine how far it has spread using a four-stage system. Stage I means cancer is found in a single lymph node region. Stage II involves two or more lymph node regions on the same side of the diaphragm (the muscle separating your chest from your abdomen). Stage III means lymph node regions on both sides of the diaphragm are affected. Stage IV indicates the cancer has spread beyond the lymph nodes into organs like the liver, lungs, or bone marrow.
Each stage also gets a letter: “A” if you have no B symptoms, or “B” if you do. So a diagnosis of “Stage IIB,” for example, means cancer in multiple lymph node regions on one side of the diaphragm, with fevers, night sweats, or significant weight loss present.
Treatment Options
Treatment depends heavily on the type, subtype, and stage. For indolent lymphomas caught early, active monitoring with no immediate treatment is a legitimate strategy. For aggressive lymphomas, treatment typically begins quickly and combines chemotherapy with targeted therapies.
One of the most significant advances in recent years is CAR T-cell therapy. This treatment collects your own T cells from a blood draw, sends them to a lab where they’re genetically engineered to recognize and attack lymphoma cells, then expands them into hundreds of millions of cells before infusing them back into your body. The entire process takes about three to five weeks from blood collection to infusion. Multiple CAR T-cell therapies are now approved for several lymphoma subtypes, including large B-cell lymphoma, follicular lymphoma, and mantle cell lymphoma.
CAR T-cell therapy can cause significant side effects. The most common is cytokine release syndrome, where the newly activated immune cells trigger widespread inflammation that can cause high fevers, low blood pressure, and difficulty breathing. A neurological side effect involving confusion, difficulty speaking, or tremors can also occur. Both are manageable with existing medications in most patients, but they’re the reason CAR T-cell therapy requires close hospital monitoring.
Survival Rates
Outcomes vary enormously by type and subtype. For non-Hodgkin lymphoma overall, the five-year relative survival rate is 74.3%, based on recent data from the National Cancer Institute. Hodgkin lymphoma generally has a better prognosis, with five-year survival rates above 85% for most stages. Early-stage Hodgkin lymphoma is one of the most curable cancers in adults.
These numbers are averages across all stages and subtypes. Individual prognosis depends on the specific subtype, how early it’s caught, your age and overall health, and how well the cancer responds to initial treatment. Indolent lymphomas, while rarely cured outright, can often be managed for many years. Aggressive lymphomas are more dangerous if untreated but more likely to be cured completely with the right therapy.