Follicular lymphoma is a type of non-Hodgkin lymphoma that can develop without warning signs. Your doctor may order a biopsy, blood tests, and diagnostic imaging to help diagnose this condition.

Follicular lymphoma is a cancer that originates in B cells, a type of white blood cell made in your bone marrow. B cells travel through the bloodstream to lymph nodes around your body, where they mature and become active when they encounter pathogens like viruses and bacteria.

In follicular lymphoma, cancerous B cells cluster together into clumps that resemble healthy immune cell bundles in the lymph node called “follicles.” This is how follicular lymphoma gets its name.

Approximately 2.4 new cases of follicular lymphoma per 100,000 people occur each year in the United States. As a slow-growing cancer, its survival rates are favorable. At the earliest stage, the 5-year relative survival rate for follicular lymphoma is around 97%.

Most people diagnosed with follicular lymphoma visit their doctor after noticing a swollen lymph node that doesn’t hurt but tends to come and go.

Lymph nodes in the neck, underarms, abdomen, and groin are among those most commonly affected. Lumps in these areas of the body are often noticeable, prompting a visit to the doctor.

However, not everyone develops an obvious swollen lymph node. With around 800 lymph nodes in your body, follicular lymphoma might affect those that you can’t see or feel.

Fever, weight loss, extreme fatigue, and night sweats are other symptoms of follicular lymphoma that might bring you to the doctor’s when a lump isn’t present.

After an initial physical exam and review of your medical history, your doctor will consider your symptoms and your risk factors for conditions like follicular lymphoma.

You may have a higher risk of developing follicular lymphoma if you:

  • have a family member who has been diagnosed with the condition
  • are over the age of 60
  • have been exposed to certain chemicals and infections

Your symptoms and medical history determine the course of testing for follicular lymphoma. You might not need every test, or you may need additional testing to help rule out other medical conditions.

Physical exam

The physical exam takes place at your initial doctor visit. Your doctor checks your weight, vital signs such as heart rate and respiration, and your baseline neurologic and motor function.

They’ll gently check your lymph nodes by touch. A typical lymph node is small, usually less than 1 to 2 centimeters (cm).

Blood tests

Blood tests use a sample of your blood to check variables like blood cell count, proteins, and enzyme levels.

These tests can give your doctor an overview of how your organ systems are functioning and provide information about the growth and spread of cancer.

Tests your doctor might order include:

  • Complete blood count (CBC): This examines levels of red blood cells, white blood cells, and platelets.
  • Chemistry panel: This provides insight into organ function by testing enzymes, fats, proteins, glucose, and electrolytes.
  • Lactate dehydrogenase (LDH) test: This measures LDH, an enzyme that can indicate tissue damage from cancer or other illnesses.
  • Beta-2 microglobulin test: This detects beta-2 microglobulin, a protein on the surface of B cells that is released into the bloodstream during rapid cell turnover, such as that from cancer.

Biopsy

A lymph node biopsy is one of the core diagnostic tests for follicular lymphoma. Your doctor will use a needle to withdraw cells from inside your lymph node to view under a microscope. In some cases, the entire lymph node is removed in a biopsy.

Pathologists examine your lymph node tissue on the microscopic level. They look for characteristic features of follicular lymphoma, like unusual B-cell structure and cancerous B-cell clusters.

Diagnostic imaging

Diagnostic imaging can help doctors determine the stage of follicular lymphoma. CT and PET scans provide a visual of areas in your body that your doctor can’t see otherwise.

A radiologist performs these scans using special equipment. You may have a dye injected into your vein to help highlight areas of inflammation or cancerous changes.

Diagnostic imaging helps reveal the size and extent of follicular lymphoma and can also help doctors track treatment progress.

Bone marrow test

Your doctor recommends a bone marrow test when it’s necessary to determine if follicular lymphoma has spread to your bone marrow, known as involvement. Bone marrow involvement is present in as many as 70% of people diagnosed with the disease and indicates a more advanced form of the cancer.

After all your diagnostic tests are complete, your doctor stages follicular lymphoma using guidelines from the Ann Arbor staging system and the Lugano Classification.

  • Stage 1: Involvement of a single lymph node or group of adjacent lymph nodes.
  • Stage 2: Involvement of two or more groups of lymph nodes on the same side of the diaphragm muscle.
  • Stage 3: Involvement of lymph nodes on both sides of the diaphragm or the involvement of lymph nodes above the diaphragm with spleen involvement.
  • Stage 4: Widespread lymph node involvement with bone marrow and other organs affected.

Your doctor may add the letter “A, B, or X” to your stage to include details about your diagnosis.

  • A: This refers to no significant weight loss, night sweats, or fever.
  • B: This means significant weight loss, night sweats, or fever are present.
  • X: This means the lymphoma is larger than 10 cm.

Once you’ve received a diagnosis of follicular lymphoma, your next steps focus on fully understanding the condition and deciding on your treatment course.

When follicular lymphoma is in its earliest stages, doctors sometimes take a wait-and-see approach. This is called “active surveillance” or “watchful waiting.” Your doctor will recommend this if the side effects of treatment are more harmful than the cancer at its current stage.

People treated with watchful waiting have similar survival outcomes in follicular lymphoma to those who start cancer therapies early.

When the disease is more advanced, doctors will recommend starting treatments like:

  • radiation therapy
  • chemoimmunotherapy
  • targeted therapies, like monoclonal antibody therapy or chimeric antigen receptor T-cell (CAR T) therapy

Even though follicular lymphoma is a slow-growing cancer with favorable survival outcomes, receiving a diagnosis can be overwhelming. It’s completely natural to have questions and concerns or just need space to process. Your healthcare team is here to treat the cancer and support you through every step.

Your questions and concerns are completely valid. Here are a few topics you might want to discuss with your doctor:

  • What does my stage of follicular lymphoma indicate?
  • Will I need more tests, and how often?
  • What treatment options do you recommend, and why?
  • Should I consider a clinical trial?
  • Will this diagnosis affect my day-to-day life or routines?
  • What mental health or emotional support resources are available?

Follicular lymphoma is a type of slow-growing non-Hodgkin lymphoma that can develop without obvious symptoms. Many people are first diagnosed after visiting the doctor for a painless, swollen lymph node.

After a physical exam, your doctor will order diagnostic tests to help verify follicular lymphoma. You may need bloodwork, a biopsy, imaging scans, or a bone marrow test.