Follicular lymphoma is a slow-growing cancer that spreads through a person’s lymphatic system. Because of its slow growth rate, people may not have any symptoms at diagnosis. It can be more aggressive in later stages, but it is rare for a person to reach this level of advancement. Doctors may treat follicular lymphoma as they would a chronic condition, and the outlook is generally positive.
This article explains what follicular lymphoma is alongside an overview of the different types, symptoms, treatment options, and outlook of this condition.
Follicular lymphoma is a type of indolent non-Hodgkin lymphoma. “Indolent” means that the cancer grows slowly instead of being “aggressive”, where cells grow more quickly.
Follicular lymphoma spreads through a person’s lymphatic system, which is part of the immune system. In follicular lymphoma, white blood cells start multiplying abnormally. White blood cells are also known as B cells or B lymphocytes. These then collect in lymph nodes and elsewhere in the person’s body.
Follicular lymphoma is usually incurable but responds well to treatment. A person can live with follicular lymphoma for many years, even decades, after diagnosis.
Doctors have identified two subtypes of follicular lymphoma that behave differently from standard follicular lymphoma. For this reason, they require different treatment.
Duodenal-type follicular lymphoma
Duodenal-type follicular lymphoma was first recognized in the World Health Organization’s classification update in 2016. Some people refer to it as primary gastrointestinal follicular lymphoma. It is a very slow-growing follicular lymphoma that starts in the small intestine, usually in one portion of the duodenum.
Some people with this subtype experience abdominal pain and heartburn, or people may experience no symptoms at all.
Duodenal-type follicular lymphoma rarely spreads to other areas of the lymphatic system. Doctors can sometimes diagnose this type at an early stage, unlike most other follicular lymphomas.
Pediatric-type follicular lymphoma
Pediatric-type follicular lymphoma is a very rare form of follicular lymphoma that arises in the head and neck lymph nodes. It mostly affects children but can also affect adults.
Treatment for pediatric follicular lymphoma is
People with follicular lymphoma often have no symptoms at the time they receive a diagnosis. This is because it grows slowly.
According to Cancer Research UK, the most common symptom of follicular lymphoma is swelling in a person’s neck, armpit, groin, or stomach. Swelling is often painless and happens due to white blood cells collecting in the lymph nodes.
Other symptoms of follicular lymphoma can include:
- drenching night sweats
- severe tiredness
- unexplained weight loss
- skin rash or itching
- pain in the chest, abdomen, or bones
Doctors may refer to the combination of drenching night sweats, fever, and unexplained weight loss as B symptoms. These are the primary symptoms of follicular lymphoma.
Other signs and symptoms may occur depending on the location and size of the cancer and how fast it is spreading. These can include:
Doctors do not yet fully understand the causes of follicular lymphoma. However, if a person has a close relative with the condition, they may have a
The exact cause of non-Hodgkin lymphoma, of which follicular lymphoma is a subtype, is also not known. However, older age, being male, and having a weakened immune system may increase a person’s risk of developing the condition.
- being over 75 years old
- having a weakened immune system, possibly due to conditions such as HIV, or to immunosuppressant drugs, which weaken the immune system
- having an autoimmune disease, such as celiac disease, Sjogren’s syndrome, lupus and rheumatoid arthritis
- having a family history of the condition
- being exposed to high levels of ionizing radiation
- being exposed to certain ingredients in herbicides and pesticides
- having other viruses, such as human T-cell lymphotrophic virus and Epstein Barr virus
- having an inherited immune disorder, such as hypogammaglobulinemia or Wiskott-Aldrich syndrome
- having helicobacter pylori infection
If doctors suspect follicular lymphoma, they will perform tests that examine the lymph system and other parts of the body. Tests and procedures might include:
- Physical exam: This can check general health and signs of disease. A doctor will also ask about a person’s medical history.
- Complete blood count: This blood test will reveal the number of red blood cells and their amount of hemoglobin, and the number of white blood cells and platelets present in the blood.
- Blood chemistry studies: This blood test can check the amounts of certain substances in the blood.
- CT scan: This takes a series of images of areas inside the body.
- PET scan: Before a PET scan, doctors inject a small amount of radioactive glucose into a person’s vein. The PET scanner rotates around the body to detect where glucose is most readily in use. Malignant cells will appear brighter as they use glucose more than normal cells.
- Bone marrow aspiration and biopsy: Using a long needle, doctors remove small amounts of blood, bone marrow, and bone. A pathologist will examine the sample under a microscope for signs of cancer.
- Lymph node biopsy: This involves removing all or part of a lymph node for examination.
Once a doctor diagnoses follicular lymphoma, they will want to know how advanced the cancer is, also known as its stage. Staging the cancer can help doctors plan a person’s treatment.
Tests that doctors use in the staging process are the same as those used for diagnosis. Other tests include:
The stages of follicular lymphoma range from stage I, which is the least advanced, to stage IV, the most advanced. Most types of follicular lymphoma are diagnosed when the cancer is already quite advanced.
The stages are as follows:
- Stage I: Localized disease affecting a single lymph node region or a single organ.
- Stage II: Two or more lymph node regions on the same side of the diaphragm.
- Stage III: Two or more lymph node regions above and below the diaphragm.
- Stage IV: Widespread disease affecting multiple organs, with or without lymph node involvement.
Due to the slow-growing nature of follicular lymphoma, it is
The cancer might be further categorized as:
- E for extranodal: This means the lymphoma has spread to an area outside of the lymphatic system.
- S for spleen: This means the lymphoma is present in the spleen.
- X: This indicates “bulky disease”, which describes a nodal mass of more than 10 centimetres or more than one-third of the chest diameter.
Sometimes, an indolent follicular lymphoma can transform into a more aggressive type. This means that it loses its slow-growing nature. This may happen years after diagnosis.
Transformations can happen in 30–40% of people with follicular lymphoma. It is then referred to as diffuse large B-cell lymphoma (DLBCL). DLBCL can spread and grow quickly. It may spread to places outside of the lymphatic system and the bone marrow.
Follicular lymphoma is a slow-growing cancer. If the condition is at stage I or II, a person may not need treatment right away until symptoms show. For stages III and IV — particularly with organ involvement — they might need treatment as soon as they are diagnosed.
According to the Leukemia and Lymphoma Society, treatment for Stage I and II follicular lymphoma might involve:
- watchful waiting, monitoring progression through periodic examinations and imaging tests
- radiation therapy
- chemotherapy with a drug called rituximab
Treatment for people with transformed or later stage follicular lymphoma can be the same as those above but might also include:
- stem cell transplant
- targeted therapy
Follicular lymphoma is usually incurable. However, doctors often treat it as they would a chronic condition. People can live for many years with follicular lymphoma.
The 5-year survival rate for follicular lymphoma between 2011 and 2017 was
Following treatment, many people can go back to a full and active life. However, the emotional toll of dealing with cancer can persist. Therefore, it is important that a person seeks help from family and friends or a medical professional to help process their experiences.
Some side effects of cancer treatment can last for months after treatment. A person might need regular checkups and further treatment to address any lingering side effects.
Follicular lymphoma is a common type of non-Hodgkin lymphoma that develops in the lymphatic system and is more common with older age. It is slow growing and usually has a good outcome.
There are many effective treatment options available depending on the extent and location of the lymphoma. People may not need to begin treatment until symptoms show.