Follicular Lymphoma

Common signs and symptoms of follicular lymphoma

Many people have no symptoms at first. FL is often found when enlarged lymph nodes are noticed on exam or imaging for other reasons. When symptoms do occur, they may include:

• Painless swelling of lymph nodes in the neck, armpits, or groin
• Fatigue
• Fever without an obvious infection
• Drenching night sweats
• Unexplained weight loss
• Feeling full quickly or abdominal discomfort, often from an enlarged spleen

As the disease and its treatment affect blood and bone marrow, people may also experience low blood counts, which can lead to tiredness, frequent infections, or easy bruising and bleeding.

Causes and risk factors

The exact cause of FL is not known. It develops when changes occur in B‑cells that allow them to become cancer cells and multiply rather than function normally. Factors associated with a higher risk include:

• Older age – most people diagnosed are in their 60s or older
• Family history of lymphoma – having a relative with lymphoma may increase risk

Current evidence does not identify a clear way to prevent FL.

Diagnosis

A biopsy of an enlarged lymph node is required to confirm the diagnosis of FL. After diagnosis, additional tests help determine the extent of disease (staging) and guide treatment, and may include:

• Blood tests
• Bone marrow biopsy to check for bone marrow involvement
• Imaging tests, such as CT or PET scans, to see which lymph nodes and organs are affected

Staging ranges from Stage I (limited to one lymph node region or nearby area) to Stage IV (spread outside the lymph system, such as to bone marrow or other organs).

Treatment overview

Because FL often grows slowly, some people do not need treatment right away. For those without symptoms or major blood count problems, doctors may recommend active surveillance (“watchful waiting”), with regular visits and tests to monitor for changes.

When treatment is needed, options may include:

• Radiation therapy – often used in early‑stage disease and can send FL into long‑term remission in some people
• Chemotherapy, sometimes combined with immunotherapy
• Immunotherapy alone or with chemotherapy, including monoclonal antibodies directed at B‑cells
• Targeted therapy for certain relapsed or refractory cases
• Stem cell transplant or cellular therapies, such as CAR T‑cell therapy, in selected people with relapsed or hard‑to‑treat disease

FL is typically a long‑term, manageable condition. Many people live for years or decades with appropriate monitoring and treatment.