Non-Hodgkin's lymphoma is cancer that originates in your lymphatic system, the disease-fighting network spread throughout your body. In non-Hodgkin's lymphoma, tumors develop from lymphocytes — a type of white blood cell.
Non-Hodgkin's lymphoma is more common than the other general type of lymphoma — Hodgkin lymphoma. Many different subtypes of non-Hodgkin's lymphoma exist. Diffuse large B-cell lymphoma and follicular lymphoma are among the most common sub types.
Advances in diagnosis and treatment of non-Hodgkin's lymphoma have helped improve the prognosis for people with this disease.
Treatment for NHL depends on which type it is, so it’s important for doctors to find out the exact type of lymphoma you have. The type of lymphoma depends on what type of lymphocyte is affected (B cells or T cells), how mature the cells are when they become cancerous, and other factors.
B-cell vs T-cell lymphomas
The lymph system is made up mainly of lymphocytes, a type of white blood cell that helps the body fight infections. There are 2 main types of lymphocytes:
B lymphocytes (B cells): B cells normally help protect the body against germs (bacteria or viruses) by making proteins called antibodies. The antibodies attach to the germs, marking them for destruction by other parts of the immune system.
T lymphocytes (T cells): There are several types of T cells. Some T cells destroy germs or abnormal cells in the body. Other T cells help boost or slow the activity of other immune system cells.
Lymphoma can start in either type of lymphocytes, but B-cell lymphomas are most common.
Indolent vs. aggressive lymphomas
Types of NHL can also be grouped based on how fast they grow and spread:
Regardless of how quickly they grow, all non-Hodgkin lymphomas can spread to other parts of the lymph system if not treated. Eventually, they can also spread to other parts of the body, such as the liver, brain, or bone marrow.
Classifying types of NHL
There are many different types of non-Hodgkin lymphoma (NHL), so classifying it can be quite confusing (even for doctors). Several different systems have been used, but the most recent system is the World Health Organization (WHO) classification. The WHO system groups lymphomas based on:
The most common symptom of non-Hodgkin lymphoma is a painless swelling in a lymph node, usually in the neck, armpit or groin.
Lymph nodes, also known as lymph glands, are pea-sized lumps of tissue found throughout the body.
They contain white blood cells that help to fight against infection.
The swelling is caused by a certain type of white blood cell, known as lymphocytes, collecting in the lymph node.
But it's highly unlikely you have non-Hodgkin lymphoma if you have swollen lymph nodes, as these glands often swell as a response to infection.
Some people with non-Hodgkin lymphoma also have other, more general symptoms.
These can include:
Other symptoms depend on where in the body the enlarged lymph glands are (for example, swollen tonsils, a lump in the tummy, or skin rashes).
A few people with lymphoma have abnormal cells in their bone marrow when they're diagnosed.
This may lead to:
Non-Hodgkin lymphoma is caused by a change (mutation) in the DNA of a type of white blood cell called lymphocytes, although the exact reason why this happens isn't known.
DNA gives cells a basic set of instructions, such as when to grow and reproduce.
The mutation in the DNA changes these instructions, so the cells keep growing. This causes them to multiply uncontrollably.
The abnormal lymphocytes usually begin to multiply in 1 or more lymph nodes in a particular area of the body, such as your neck, armpit or groin.
Over time, it's possible for the abnormal lymphocytes to spread into other parts of your body, such as your:
But in some cases non-Hodgkin lymphoma starts growing in an organ, rather than starting in a lymph node and spreading to an organ.
In most cases, people diagnosed with non-Hodgkin's lymphoma don't have any obvious risk factors. And many people who have risk factors for the disease never develop it.
Some factors that may increase the risk of non-Hodgkin's lymphoma include:
Medications that suppress your immune system: If you've had an organ transplant, you're more susceptible because immunosuppressive therapy has reduced your body's ability to fight new illnesses.
Infection with certain viruses and bacteria: Certain viral and bacterial infections appear to increase the risk of non-Hodgkin's lymphoma. Viruses linked to increased non-Hodgkin's lymphoma risk include HIV and Epstein-Barr infection. Bacteria linked to an increased risk of non-Hodgkin's lymphoma include the ulcer-causing Helicobacter pylori.
Chemicals: Certain chemicals, such as those used to kill insects and weeds, may increase your risk of developing non-Hodgkin's lymphoma. More research is needed to understand the possible link between pesticides and the development of non-Hodgkin's lymphoma.
Older age: Non-Hodgkin's lymphoma can occur at any age, but the risk increases with age. It's most common in people 60 or over.
Your doctor will likely ask you about your personal and family medical history. He or she may then have you undergo tests and procedures used to diagnose non-Hodgkin's lymphoma, including:
Physical exam: Your doctor checks for swollen lymph nodes, including in your neck, underarm and groin, as well as for a swollen spleen or liver.
Blood and urine tests: Blood and urine tests may help rule out an infection or other disease.
Imaging tests: Your doctor may recommend imaging tests to look for tumors in your body. Tests may include X-ray, CT, MRI and positron emission tomography (PET).
Lymph node test: Your doctor may recommend a lymph node biopsy procedure to remove all or part of a lymph node for laboratory testing. Analyzing lymph node tissue in a lab may reveal whether you have non-Hodgkin's lymphoma and, if so, which type.
Bone marrow test: A bone marrow biopsy and aspiration procedure involves inserting a needle into your hipbone to remove a sample of bone marrow. The sample is analyzed to look for non-Hodgkin's lymphoma cells.
Other tests and procedures may be used depending on your situation.
After your doctor has determined the extent of your non-Hodgkin's lymphoma, your cancer will be assigned a stage. Knowing your cancer's stage helps your doctor determine your prognosis and treatment options.
Stages of non-Hodgkin's lymphoma include:
Stage I: The cancer is limited to one lymph node region or a group of nearby nodes.
Stage II: In this stage, the cancer is in two lymph node regions, or the cancer has invaded one organ and the nearby lymph nodes. But the cancer is still limited to a section of the body either above or below the diaphragm.
Stage III: When the cancer moves to lymph nodes both above and below the diaphragm, it's considered stage III. Cancer may also be found in the lymph nodes above the diaphragm and in the spleen.
Stage IV: This is the most advanced stage of non-Hodgkin's lymphoma. Cancer cells are in several portions of one or more organs and tissues. Stage IV non-Hodgkin's lymphoma may also affect other parts of the body, such as the liver, lungs or bones.
Additionally, your doctor uses the letters A and B to indicate whether you're experiencing symptoms of non-Hodgkin's lymphoma:
A means that you don't have any significant symptoms as a result of the cancer.
B indicates that you may have significant signs and symptoms, such as a persistent fever, unintended weight loss or severe night sweats.
Many types of non-Hodgkin's lymphoma exist, including rare forms that are difficult for inexperienced pathologists to identify. Accurate diagnosis and staging are key to developing a treatment plan. Research shows that review of biopsy tests by pathologists who aren't experienced with lymphoma results in a significant proportion of misdiagnoses. Get a second opinion from a specialist if needed.
Which non-Hodgkin's lymphoma treatments are right for you depends on the type and stage of your disease, your overall health, and your preferences.
Treatment isn't always necessary
If your lymphoma appears to be slow growing (indolent), a wait-and-see approach may be an option. Indolent lymphomas that don't cause signs and symptoms may not require treatment for years.
Delaying treatment doesn't mean you'll be on your own. Your doctor will likely schedule regular checkups every few months to monitor your condition and ensure that your cancer isn't advancing.
Treatment for Non-Hodgkin’s Lymphoma
If you are diagnosed with non-Hodgkin’s lymphoma, your doctor will discuss the best options to treat it. This depends on several factors, including:
Your treatment for non-Hodgkin’s lymphoma cancer will be customized to your particular needs. One or more of the following therapies may be recommended to treat the cancer or help relieve symptoms.
Chemotherapy: This is the treatment most often used for non-Hodgkin’s lymphoma. And since chemotherapy may lower certain types of blood cells, a transfusion of a type of drug called blood cell growth factors may be needed. Liposomal drug delivery is an advanced way of giving chemotherapy that may help it be more effective.
Radiation Therapy: Radiation therapy may be used in early-stage lymphoma or to help symptoms such as pain. It is seldom the only treatment given.
Stem cell transplantation: If non-Hodgkin’s lymphoma does not respond to chemotherapy or if it returns, your doctor may recommend a stem cell transplant. Also, since chemotherapy often destroys healthy cells in the blood and bone marrow, patients who have certain types of chemotherapy may need stem cell transplants.