Follicle Centre Lymphoma Follicular Grade I, II – III

Follicle centre lymphoma, also known as follicular lymphoma, is the most common type of slow-growing non-Hodgkin lymphoma. This cancer develops from abnormal B cells that typically form in clusters within lymph nodes, and while it cannot be cured at present, many people live for years with this condition, often without needing treatment right away.

Table of contents

• What is follicular lymphoma?
• Who gets follicular lymphoma?
• Symptoms
• Causes and risk factors
• How doctors diagnose this condition
• Understanding grades of follicular lymphoma
• Understanding stages of follicular lymphoma
• Treatment approaches
• Outlook and living with the condition

What is follicular lymphoma?

Follicular lymphoma is a type of cancer that affects your lymphatic system, which is an important part of your immune system that helps fight infections. The lymphatic system includes tubes called lymph vessels that carry a clear liquid called lymph throughout your body, along with clusters of small structures called lymph nodes that are found in your neck, armpits, groin, and other areas^[1].

Lymphoma is a type of blood cancer that develops when white blood cells called lymphocytes grow out of control. There are two main types of lymphocytes: T cells and B cells. Follicular lymphoma develops from B cells, making it a B-cell lymphoma^[3].

The name “follicular” comes from the way the abnormal B cells typically grow. Instead of spreading randomly, they tend to cluster together in groups called follicles inside lymph nodes. These follicles look similar to the normal structures found in healthy lymph nodes^[1].

Follicular lymphoma is classified as a type of non-Hodgkin lymphoma (NHL), which is one of two main categories of lymphoma. It is the second most common type of non-Hodgkin lymphoma overall, accounting for about 20 to 30 percent of all NHL cases^[2][8].

• Lymph nodes
• Spleen
• Bone marrow
• Lymphatic system

Who gets follicular lymphoma?

Follicular lymphoma is the most common type of slow-growing lymphoma. In the United States, there are approximately 15,000 to 20,000 new diagnoses each year^[4]. In the United Kingdom, around 2,300 people are diagnosed with follicular lymphoma annually^[3].

This condition mainly affects adults over the age of 60. The average age at diagnosis is around 55 to 60 years^[2][12]. It is relatively uncommon in children and rarely diagnosed in people under 20 years of age^[2].

The condition affects people differently based on their background. It occurs more frequently in people who are white compared to those of Asian or African American descent. The rate is higher in the United States and Europe compared to other parts of the world^[2].

When follicular lymphoma does occur in children, it behaves very differently from the adult form. Doctors actually consider pediatric follicular lymphoma to be a different type of cancer. Unlike the adult type, pediatric follicular lymphoma is often curable^[4].

Symptoms

Many people with follicular lymphoma do not have any symptoms at first. Some cases are discovered during routine blood work or imaging tests done for another reason^[8]. When symptoms do appear, they often develop gradually over time.

Painless swellings

The most common symptom is one or more painless swellings, usually in the neck, armpit, or groin. These swellings are enlarged lymph nodes. They are typically firm, moveable under the skin, and do not hurt^[3][4].

General symptoms (B symptoms)

Some people experience a group of symptoms that doctors refer to as “B symptoms.” These include:

• Heavy sweating at night (night sweats)
• Fever that comes and goes with no obvious cause
• Losing a significant amount of weight without trying (more than one-tenth of your body weight)^[3][5]

Other symptoms

Additional symptoms may include:

• Feeling very tired all the time (fatigue)
• Feeling full quickly or discomfort in your abdomen, if lymph nodes or your spleen are enlarged
• Recurring infections due to weakened immune function^[8]

When follicular lymphoma affects the bone marrow (the soft tissue inside bones where blood cells are made), it can lead to:

• Low red blood cells (anemia), causing tiredness or breathlessness
• Low platelet counts, causing easy bruising or bleeding problems^[3]

If you have any of these symptoms, especially persistent swollen lymph nodes, it is important to see your doctor. These symptoms may not be related to lymphoma, but they should be checked out^[3].

Causes and risk factors

Researchers do not fully understand what causes follicular lymphoma. The condition is not inherited, meaning it does not run in families^[4].

Genetic changes

In about 85 percent of cases, changes occur in a person’s chromosomes (the structures in cells that carry genetic information). These changes happen at some point during a person’s lifetime, not at birth^[4].

The most common change involves two specific chromosomes, called 14 and 18. When genetic material from these chromosomes gets swapped, it leads to increased levels of a protein called BCL2. This protein prevents cells from dying when they should, allowing abnormal B cells to survive and multiply^[2].

However, this chromosomal change alone does not cause follicular lymphoma. Scientists have found that healthy people can have cells with this same change, but they never develop lymphoma^[2].

Risk factors

Certain factors appear to increase the risk of developing follicular lymphoma, though they do not directly cause it:

• Being age 65 or older
• Being white (compared to other racial groups)^[4]
• Exposure to certain chemicals, such as pesticides and herbicides^[2]

Follicular lymphoma is not contagious and cannot be spread from person to person.

How doctors diagnose this condition

Diagnosing follicular lymphoma involves several steps. Your doctor will want to confirm that you have lymphoma and determine exactly what type it is.

Lymph node biopsy

The main test to diagnose lymphoma is a lymph node biopsy. During this procedure, a doctor removes part or all of a swollen lymph node. The sample is sent to a laboratory where a specialist examines it under a microscope. This is the only way to know for certain if you have follicular lymphoma^[3][4].

Blood tests

You will likely have blood tests to check your overall health and look for any abnormalities in your blood cell counts^[3].

Imaging tests

If your doctor diagnoses lymphoma, you will need additional tests to find out where the cancer is located in your body. These may include:

• PET scan (positron emission tomography scan): Creates images showing where cancer cells are active in your body
• CT scan (computed tomography scan): Takes detailed pictures of the inside of your body^[3][4]

Bone marrow test

A bone marrow biopsy involves taking a small sample of bone marrow, usually from your hip bone, to check if lymphoma cells are present there. This test helps determine how advanced the lymphoma is^[3].

Understanding grades of follicular lymphoma

After diagnosing follicular lymphoma, doctors assign it a grade based on how the cells look under a microscope. The grade tells your doctor how quickly the lymphoma is likely to grow and spread^[3].

Follicular lymphoma is usually slow-growing and called a low-grade lymphoma. However, doctors further divide follicular lymphoma into specific grades^[3]:

• Grade 1: Contains 0 to 5 large abnormal cells (called centroblasts) in each high-power field of view under the microscope
• Grade 2: Contains 6 to 15 centroblasts per high-power field
• Grade 3: Contains more than 15 centroblasts per high-power field. This grade is further divided into:
  • Grade 3A: Large cells are mixed with smaller cells
  • Grade 3B: Solid sheets of large cells are present^[6]

Grades 1, 2, and 3A are considered low-grade or slow-growing. Doctors usually treat them the same way. Grade 3B grows faster and is treated more like a high-grade lymphoma^[3][6].

The more large cells present in the lymphoma, the more aggressively it tends to behave. Lymphomas with more large cells also have a higher chance of transforming into a different, more aggressive type of lymphoma called diffuse large B-cell lymphoma^[6].

Understanding stages of follicular lymphoma

Cancer staging describes where the cancer is located in your body and how far it has spread. Follicular lymphoma stages range from I to IV^[4]:

• Stage I: Cancer is found in one or more lymph nodes in a single area
• Stage II: Cancer is in lymph nodes either above or below your diaphragm (the band of muscle that separates your chest from your abdomen)
• Stage III: Cancer is in lymph nodes on both sides of your diaphragm
• Stage IV: Cancer has spread beyond your lymph nodes to other organs such as bone marrow, liver, or spleen^[4]

Because follicular lymphoma often does not cause symptoms right away, most people have stage III or IV disease by the time they are diagnosed^[4]. Only about one-third of people have stage I or II at diagnosis^[6].

Having advanced-stage disease does not necessarily mean you will need immediate treatment. Many people with stage III or IV follicular lymphoma can live for years without treatment^[2].

Treatment approaches

Treatment for follicular lymphoma depends on several factors, including the stage and grade of your lymphoma, whether you have symptoms, and your overall health. The goal of treatment is to control the disease and maintain quality of life.

Watch and wait (active surveillance)

If you have follicular lymphoma but do not have any symptoms, you may not need treatment right away. This approach is called “watch and wait” or active surveillance. Research shows that early treatment of symptom-free follicular lymphoma does not improve survival^[4].

During active surveillance, your health care provider will check on your condition regularly through physical exams, blood tests, and imaging scans. You will only start treatment if you develop symptoms or if the disease begins to progress^[4][8].

Radiation therapy

For early-stage follicular lymphoma (stage I or II), doctors often use radiation therapy. This treatment uses high-energy rays to kill cancer cells. In about half of people with early-stage disease, radiation therapy can send the cancer into long-term remission, meaning it may not return for many years^[4].

Targeted therapy with monoclonal antibodies

One of the most common treatments for follicular lymphoma is a drug called rituximab. This is a type of monoclonal antibody, which is a laboratory-made protein that targets a specific marker on cancer cells. Rituximab can be given alone or combined with other treatments^[8].

Chemotherapy

Chemotherapy uses strong medicines to kill cancer cells throughout your body. For follicular lymphoma, chemotherapy is often combined with monoclonal antibodies in an approach called chemoimmunotherapy. This combination can be effective in achieving remission^[8].

Immunotherapy and targeted therapies

Immunotherapy treatments help your immune system recognize and attack cancer cells. Several newer targeted therapies have been developed for follicular lymphoma, offering additional options when other treatments stop working^[8].

Clinical trials

Many people with follicular lymphoma may be eligible to participate in clinical trials, which test new treatments or combinations of treatments. Clinical trials give patients access to cutting-edge therapies that may not yet be widely available^[8].

Outlook and living with the condition

Follicular lymphoma is generally not considered curable at present. However, it is usually a slow-growing cancer, and many people live for many years with the condition^[4][8].

The typical survival for people with follicular lymphoma has historically been about 8 to 10 years, but newer treatments developed in recent decades have led to even longer survival times. Most people with this condition die with it, not from it^[2][4].

Follicular lymphoma is typically viewed as a chronic condition that can be managed over time. Even when the disease responds well to treatment and goes into remission, it often returns at some point. However, there are many effective treatments available, and the disease can often be controlled with repeated courses of therapy^[8].

Healthcare providers are hopeful about the future. Newer treatments, particularly newer immunotherapy drugs, are showing promising results. There is hope that these advances may eventually lead to a cure^[4].

Living with follicular lymphoma means regular follow-up with your healthcare team, monitoring for any changes, and being aware of symptoms that might signal the disease is becoming more active. Many people are able to maintain a good quality of life between treatments.