Follicular lymphoma is a type of lymphoma. Lymphoma is cancer that affects the lymphatic system. The lymphatic system is made up of organs, glands, tubelike vessels and clusters of cells called lymph nodes. It's part of the body's germ-fighting immune system. Follicular lymphoma can affect the lymph nodes, bone marrow and other organs.

There are many types of lymphoma. They are often divided into two categories: Hodgkin lymphoma and non-Hodgkin lymphoma. Follicular lymphoma is a type of non-Hodgkin lymphoma.

Follicular lymphoma gets its name from the fact that the cancer starts in the follicles of the lymph nodes. Lymph node follicles are groups of germ-fighting white blood cells that are inside each lymph node. When these white blood cells become cancer cells, they may build up in the lymph nodes and continue to gather in groups that look like follicles.

Follicular lymphoma tends to grow slowly. It's often not found until it affects many parts of the body. Treatment may include radiation therapy, chemotherapy, immunotherapy targeted therapy and CAR-T cell therapy.

Types

Types of follicular lymphoma include:

• Classic follicular lymphoma.
• In situ follicular B-cell neoplasm.
• Duodenal-type follicular lymphoma.
• Pediatric-type follicular lymphoma.

Follicular lymphoma grows slowly and may never cause symptoms.

When they happen, follicular lymphoma symptoms may include:

• Painless swelling in the neck, armpit or groin.
• Fatigue.
• Fever.
• Night sweats.
• Losing weight without trying.
• Feeling full quickly.

When to see a doctor

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you.

It's not clear what causes follicular lymphoma. This cancer starts inside the follicle of a lymph node. A follicle is a group of cells inside the lymph node. The follicle contains germ-fighting white blood cells called B cells. When there is no infection to fight, the B cells rest in the follicle.

When an infection happens in the body, the follicle can form an area that helps train the B cells to fight the infection. As part of this process, the B cells go through changes that make them better at fighting the specific infection. The B cells also make a lot more B cells to help with the fight. Then the B cells go out into the body to help fight the infection.

Follicular lymphoma happens when something goes wrong during this training process. Changes happen that turn the B cells into cancer cells. The cancer cells don't learn to fight infections. Instead, they build up in the lymph nodes. They also can build up in other parts of the lymphatic system.

Follicular lymphoma can affect the:

• Lymph nodes.
• Bone marrow.
• Spleen.
• Liver.
• Digestive tract.
• Skin.

Factors that can increase the risk of follicular lymphoma include:

• Older age. Follicular lymphoma can happen at any age. But it's most common in people 60 or older.
• Race. White people are more likely to develop follicular lymphoma than are people of other races.
• Having a family history of lymphoma. Having a relative with follicular lymphoma may increase your risk.

There is no known way to prevent follicular lymphoma.

Complications of follicular lymphoma can include transformation into a fast-growing lymphoma and complications from treatment.

Turning into a fast-growing lymphoma

Sometimes a follicular lymphomas can transform into a fast-growing lymphoma, such as diffuse large B-cell lymphoma. These lymphomas often have a worse prognosis and need stronger treatments.

Complications of treatment

Complications of follicular lymphoma treatment may include a decrease in bone density, toxicity from the medicines, reactivating viruses such as hepatitis B and C, and tumor lysis syndrome. Tumor lysis syndrome is a serious condition that can happen when cancer cells break down quickly after treatment. When these cells die, they release substances into the bloodstream that can overwhelm the body. This can lead to conditions that affect the kidneys and other organs.

Follicular lymphoma diagnosis often begins with a physical exam that checks for swollen lymph nodes in the neck, underarms and groin and a swollen spleen or liver. Other tests and procedures might include blood tests, imaging tests and taking a sample of tissue for lab testing.

Blood tests

Tests of your blood may help rule out an infection or other conditions. Blood tests also measure levels of lactate dehydrogenase (LDH), which may be higher if the lymphoma is changing to a more aggressive type.

Imaging tests

Imaging tests make pictures of the body. They can show the location and extent of a follicular lymphoma. Tests might include MRI, CT and positron emission tomography (PET) scans.

Lymph node biopsy

Your healthcare professional may suggest a lymph node biopsy to look for cancer cells. A biopsy is a procedure to remove a sample of tissue for testing in a lab. A lymph node biopsy involves removing all or part of a lymph node. In the lab, tests may show whether you have follicular lymphoma.

Bone marrow aspiration and biopsy

Bone marrow aspiration and biopsy are procedures to collect cells from the bone marrow for testing. Bone marrow is the soft matter inside bones where blood cells are made. Bone marrow has a solid part and a liquid part.

In a bone marrow aspiration, a needle is used to draw a sample of the fluid. In a bone marrow biopsy, a needle is used to collect a small amount of the solid tissue. The samples are typically taken from the hip bone. The samples go to a lab for testing. In follicular lymphoma, this procedure is done to help determine the cancer's extent.

Testing lymphoma cells in the lab

Lymphoma cells collected from a lymph node biopsy or bone marrow aspiration and biopsy go to a lab for testing. In the lab, specialized tests look for specific things about the cells. The healthcare team uses the results to decide on the type of lymphoma that you have.

To decide whether the cells are follicular lymphoma cells, the healthcare professionals in the lab look for:

• Proteins on the surface of the cancer cells. Follicular lymphoma cells have certain proteins on their surfaces and a distinct growth pattern that help identify them.
• Changes in the cancer cells' DNA. Cancer happens when cells get changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In follicular lymphoma, the cells have a gene change that alters the arrangement of their DNA. This is known as translocation. This gene change causes the cells to multiple rapidly.

Follicular lymphoma staging

If you're diagnosed with follicular lymphoma, the next step is to determine the cancer's extent, called the stage. Imaging tests and biopsies may be used to determine the stage of your follicular lymphoma. Your healthcare team uses the cancer stage to help create your treatment plan.

The stages of follicular lymphoma range from 1 to 4:

• Stage 1 follicular lymphoma. At this stage, only one lymph node region or one site outside of the lymph nodes is affected.
• Stage 2 follicular lymphoma. At stage 2, follicular lymphoma involves two or more lymph node regions on the same side of the diaphragm.
• Stage 3 follicular lymphoma. At this stage, the disease involves lymph node regions or other parts of the lymphatic system on both sides of the diaphragm. It also may involve a site outside of the lymphatic system, such as the spleen.
• Stage 4 follicular lymphoma. Stage 4 follicular lymphoma involves regions outside of the lymph nodes.

Follicular lymphoma prognosis

The cancer prognosis tells you how likely it is that the cancer can be controlled. Your healthcare team can get a general sense of your outlook using your follicular lymphoma stage. But the stage can't tell your future. Your personal prognosis may depend on:

• Your age.
• Your overall health.
• The cancer's stage.
• Lymph node and bone marrow biopsy results.

Talk with your healthcare team about your prognosis if you want to know what to expect. Your healthcare team can explain what they consider when thinking about your prognosis.

Follicular lymphoma survival rates

The chance of surviving follicular lymphoma is quite good for most people. To understand follicular lymphoma survival rates, experts study many people with follicular lymphoma to see how many are living five years after their diagnosis.

For stage 1 follicular lymphoma, the chance of surviving at least five years is 97%. As the cancer spreads, the chances get lower. For stage 4 follicular lymphoma, the chances of surviving at least five years is about 83%.

Keep in mind that survival statistics take five years to collect. The most recent survival rates include people who had follicular lymphoma treatment more than five years ago. These people may not have had access to the latest treatments. Over the last few decades, follicular lymphoma death rates have been falling and survival rates have been increasing.

Follicular lymphoma treatments may include the "watch and wait" method, radiation therapy, immunotherapy, chemotherapy, targeted therapy, and CAR-T cell therapy. Which treatment is best for you depends on the extent of your cancer, called the stage. Your healthcare team also considers how quickly the cancer is growing, your overall health and what you prefer.

Watch and wait

If your follicular lymphoma seems to be growing slowly and doesn't cause symptoms, you might not need treatment right away. Instead, you may have checkups every few months. The checkups help your healthcare team watch your condition and see whether your cancer is growing.

Radiation therapy

Radiation therapy for cancer is a treatment that uses powerful energy beams to kill cancer cells. The energy can come from X-rays, protons or other sources. During radiation therapy, you lie on a table while a machine moves around you. The machine directs radiation to precise points on your body.

For people with early-stage follicular lymphoma, radiation therapy may be the only treatment needed. Radiation therapy also may be combined with medicines such as immunotherapy or chemotherapy. For advanced follicular lymphoma, radiation can relieve symptoms and improve quality of life.

Immunotherapy

Immunotherapy for cancer is a treatment with medicine that helps the body's immune system kill cancer cells. The immune system fights off diseases by attacking germs and other cells that shouldn't be in the body. Cancer cells survive by hiding from the immune system. Immunotherapy helps the immune system cells find and kill the cancer cells.

Immunotherapy may be used as a first line treatment for follicular lymphoma. It is often combined with chemotherapy. Immunotherapy also may be combined with other medicines in people with advanced cancer or cancer that has come back after treatment.

Chemotherapy

Chemotherapy treats cancer with strong medicines. There are many chemotherapy medicines. Most chemotherapy medicines are given through a vein. Some come in pill form.

Chemotherapy may be used as a first line treatment for follicular lymphoma. It is often combined with immunotherapy. Chemotherapy may be combined with other medicines in people with advanced cancer or cancer that has come back after treatment.

Targeted therapy

Targeted therapy for cancer is a treatment that uses medicines that attack specific chemicals in the cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die. Targeted therapy is often combined with immunotherapy to treat follicular lymphoma that has come back after treatment.

CAR-T cell therapy

Chimeric antigen receptor (CAR)-T cell therapy trains the immune system cells to fight follicular lymphoma. This treatment begins with removing some white blood cells, including T cells, from the blood.

The cells are sent to a lab. In the lab, the cells are treated so that they make special receptors. The receptors help the cells recognize a marker on the surface of the lymphoma cells. Then the cells go back into the body. There they find and destroy the follicular lymphoma cells.

CAR-T cell therapy might be an option for advanced follicular lymphoma that has not responded to other treatments. It also may be an option for follicular lymphoma that has come back after treatment.

With time, you'll likely find what helps you cope with the uncertainty and worry of a cancer diagnosis. Until then, you may find that it helps to:

Learn enough about follicular lymphoma to make decisions about your care

Ask your healthcare team about your cancer, including your test results, treatment options and, if you want, your prognosis. As you learn more about follicular lymphoma, you may become more confident in making treatment decisions.

Keep friends and family close

Keeping your close relationships strong can help you deal with follicular lymphoma. Friends and family can provide the practical support you may need, such as helping take care of your home if you're in the hospital. And they can serve as emotional support when you feel overwhelmed by having cancer.

Find someone to talk with

Find someone who is willing to listen to you talk about your hopes and worries. This may be a friend or family member. The concern and understanding of a counselor, medical social worker, clergy member or cancer support group also may be helpful.

Ask your healthcare team about support groups in your area. Other sources of information include the National Cancer Institute and the American Cancer Society.

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you.

If your healthcare professional thinks you might have follicular lymphoma, you may be referred to a doctor who specializes in diseases that affect blood cells, called a hematologist. If a cancer diagnosis is made, you also may be referred to a doctor who specializes in treating cancer, called an oncologist.

Because appointments can be brief, it's a good idea to be prepared. Here's some information to help you get ready.

What you can do

• Be aware of anything you need to do ahead of time. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
• Write down symptoms you have, including any that may not seem related to the reason for which you scheduled the appointment.
• Write down important personal information, including major stresses or recent life changes.
• Make a list of all medicines, vitamins and supplements you're taking and the doses.
• Take a family member or friend along. It can be hard to remember all the information provided during an appointment. Someone who goes with you may remember something that you missed or forgot.
• Write down questions to ask your healthcare team.

Your time with your healthcare team is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For follicular lymphoma, some basic questions to ask include:

• Do I have follicular lymphoma?
• What is the stage of my follicular lymphoma?
• Will I need more tests?
• What are the treatment options?
• How much does each treatment prolong my life or increase my chances of a cure?
• What are the potential side effects of each treatment?
• How will each treatment affect my daily life?
• Is there one treatment option you believe is the best?
• What would you recommend to a friend or family member in my situation?
• Should I see a specialist?
• Are there any brochures or other printed material that I can take with me? What websites do you recommend?
• What will determine whether I should plan for a follow-up visit?

Don't hesitate to ask other questions.

What to expect from your doctor

Be prepared to answer questions, such as:

• When did your symptoms begin?
• Do your symptoms happen all the time or do they come and go?
• How bad are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?
• Have you had any fevers, night sweats or weight loss?
• Have you noticed any lumps, swelling or pain anywhere in your body?
• Do you have any other health conditions, such as diabetes, heart disease or kidney disease?
• What are your biggest concerns about your diagnosis or treatment?