Before you learn about follicular lymphoma, understand the basics.
Click here to learn about lymphoma >>

What is Follicular Lymphoma?

Understanding the nature of follicular lymphoma can help you to cope with a diagnosis and know what to expect.

Key takeaways:

Follicular lymphoma is a form of non-Hodgkin’s lymphoma that affects B-cells

Follicular nature of follicular lymphoma

Follicular nature of follicular lymphoma

Follicular lymphoma is the most common type of indolent, or slow-growing, non-Hodgkin’s lymphoma.1 In general, non-Hodgkin’s lymphoma symptoms can vary based on where it is in the body. In some cases, it might not cause any symptoms until it grows quite large. For example, follicular lymphoma grows in many lymph nodeLymph Node
A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.
sites throughout the body and in the bone marrow. Often, one of the first signs of FL is a painless swelling in the neck, armpit, or groin caused by enlarged lymph nodes.2

So what makes follicular lymphoma different from other B-cell lymphomas? The term “follicular” refers to the way the cancerous cells grow and clump together in circular patterns.2

What are the risk factors for follicular lymphoma?3

The causes of follicular lymphoma are unknown. However, there are certain risk factors that may increase the chance of a person developing follicular lymphoma:

The important thing to remember is that having a risk factor or many risk factors does not mean that you will develop lymphoma. Many people who are diagnosed with lymphoma may have few, if any, risk factors.

How does follicular lymphoma behave?

While people may live with follicular lymphoma for many years, it’s important to recognize that there is no cure for the disease. In most cases, following a period of remission, the disease will come back, or “relapse.” A person may experience multiple relapses, and these relapses can occur years apart.3

Since your follicular lymphoma is likely to relapse, you should always plan for what’s next by evaluating your future treatment options and determining what will make the most sense for you when the disease progresses.

Learn more about follicular lymphoma treatment options>>

Follicular lymphoma facts and figures

Follicular lymphoma accounts for 22% of non-Hodgkin’s lymphoma cases
  • Incidence
    • Follicular lymphoma is the second most common type of non-Hodgkin’s lymphoma, representing about 22% of non-Hodgkin’s lymphomas.3,4
    • As of 2014, an estimated 584,133 people are living with the disease or are in remission.5
    • Nearly 14,000 patients are diagnosed with follicular lymphoma in the United States each year. It is estimated that there will be 15,807 new cases in 2015.3,6
Follicular lymphoma generally affects older people
  • Age
    • Generally, follicular lymphoma affects older people.4
    • About half of non-Hodgkin’s lymphoma patients are over 66 years old.

Next section: How is Follicular Lymphoma Diagnosed? >>

Indications and Usage

ZEVALIN® (ibritumomab tiuxetan) injection for intravenous use is a prescription medication that has three parts: two infusions of rituximab and one injection of Yttrium-90 (Y-90) ZEVALIN. Rituximab is used to reduce the number of B-cells in your blood and Y-90 ZEVALIN is given to treat your non-Hodgkin's lymphoma (NHL).

The ZEVALIN therapeutic regimen is used to treat patients with:

  • Low-grade or follicular B-cell NHL that has relapsed during or after treatment with other anticancer drugs.
  • Newly diagnosed follicular NHL following a response to initial anticancer therapy.

Patient Important Safety Information

What Is the Most Important Safety Information I Should Know About ZEVALIN Treatment?

The following section provides an overview of the most important safety information you should know about ZEVALIN, including side effects. Not all of the safety information about ZEVALIN treatment is included here. For complete safety information, please see the accompanying full prescribing information for ZEVALIN. Additional information may also be found on the ZEVALIN Website ( or by speaking with your health care provider. Because ZEVALIN treatment includes the use of rituximab, please see the rituximab medication guide (


  • Serious Infusion Reactions: Rituximab, alone or as part of the ZEVALIN treatment, may cause serious infusion reactions. Deaths have occurred within 24 hours of rituximab infusion, an important component of the ZEVALIN treatment. Tell your doctor or infusion nurse or get medical treatment right away if you develop fever or chills, a rash, itching, dizziness, swelling of your hands, feet or face, throat irritation or trouble breathing during or after receiving the ZEVALIN treatment.
  • Extended and Severe Decreases in Your Blood Counts (Cytopenias): Your doctor will monitor your blood counts after receiving the ZEVALIN treatment. Decreased blood counts can occur late and continue for more than 12 weeks after receiving ZEVALIN. Tell your doctor if you have a fever, feel too tired to do daily activities, feel weak, develop bruises or pinpoint red or purple spots on your skin, have unusual bleeding or notice blood in your urine or stool.
  • Severe Skin or Mucous Membrane Reactions: If you experience any reactions related to your skin or mucous membranes (e.g. mouth, nose), your infusion of rituximab and Y-90 ZEVALIN should be discontinued.

Dosing Warning: The dose of Y-90 ZEVALIN should not exceed 32.0 mCi (1184 MBq).

Additional Safety Information:

  • Risk of Developing Myelodysplastic Syndrome, Leukemia and Other Malignancies (Cancers): The radiation dose resulting from therapeutic exposure to Y-90 ZEVALIN may result in secondary malignancies.

    Myelodysplastic syndrome (MDS; a type of pre-cancerous bone marrow abnormality) and/or Acute Myelogenous Leukemia (AML, a type of cancer of the blood) were reported in 5.2% (11/211) of patients treated with Y-90 ZEVALIN for relapsed or refractory non-Hodgkin's lymphoma (NHL) in clinical studies, and 1.5% (8/535) of all patients included in the expanded-access trial, with median follow-up of 6.5 and 4.4 years, respectively. Among the 19 reported cases, the median time to diagnosis of MDS or AML was 1.9 years following the ZEVALIN therapy; however, the total incidence continues to increase.

    Among 204 newly diagnosed patients who received Y-90 ZEVALIN, following complete or partial response to initial anticancer therapy, 7 patients (3.4%) were diagnosed with MDS/AML after receiving ZEVALIN treatment, compared to one patient (0.5%, 1/205) in the control arm, with a median follow-up of 7.3 years. Deaths due to secondary new malignancies occurred in 8 (3.9%) patients treated with ZEVALIN compared to 3 (1.5%) patients in the control arm of the study. Deaths due to MDS or AML occurred in 5 (2.5%) patients treated with ZEVALIN compared to no patients in the control arm.

  • Infusion Site Leakage: ZEVALIN may leak from your vein or infusion site. Your doctor will monitor you during treatment and will stop the infusion and switch to another vein, if this occurs during treatment.
  • Immunization: Do not get a vaccine that contains live virus for at least 12 months following ZEVALIN treatment.
  • Precautions During and After Administration: Your doctor will discuss precautions with you to minimize radiation exposure.
  • Potential for Birth Defects: ZEVALIN therapy may cause harm to an unborn baby, please tell your doctor if you are pregnant or plan to become pregnant.
  • Reproductive Organs: There is a risk that ZEVALIN therapy will affect the male and female reproductive organs. Use birth control during treatment and for a minimum of 12 months following ZEVALIN therapy.
  • Nursing Mothers: Discontinue nursing during and after ZEVALIN treatment.
  • Adverse Reactions (Side Effects): The most common adverse reactions (≥10%) in clinical trials with ZEVALIN were: decreases in blood counts, tiredness, inflammation of the nose and upper throat, nausea (upset stomach), abdominal (stomach) pain, weakness, cough, diarrhea, and fever. The most serious adverse reactions of ZEVALIN are prolonged and severe reduction in the number of blood counts and secondary cancers.

    When administered following initial anticancer therapy, grade 3/4 adverse reactions of ZEVALIN include prolonged and severe decrease in blood counts (decrease in platelets [51%], decrease in neutrophils (a type of white blood cell) [41%], decrease in total white blood cells [36%], decrease in lymphocytes [18%], and decrease in red blood cells or hemoglobin [5%]), and secondary cancers (12.7%). Reductions in blood cells were more severe and more prolonged among 11 (5%) patients who received ZEVALIN after first-line fludarabine or a fludarabine-containing anticancer regimen as compared to patients receiving non-fludarabine-containing regimens. Grade 3/4 infections occurred in 8% of ZEVALIN-treated patients and in 2% of controls and included neutropenic sepsis (fever and infection due to decrease in the number of neutrophils [1%]), bronchitis, catheter sepsis (bacterial infection in the blood related to catheter), diverticulitis (inflammation in the intestines), shingles or blistering skin rash caused from herpes virus reactivation, flu, lower air passage infection, sinusitis (swelling of the sinuses), and upper air passage infection.

    Grade 3/4 adverse reactions of ZEVALIN in recurring NHL patients include prolonged and severe reduction of blood cells (decrease in platelets [63%], decrease in neutrophils [60%], decrease in red blood cells or hemoglobin [17%], and ecchymosis (small blue or purple patch on the skin or mucous membrane [<1%])) and secondary cancers (5.2%). Serious infections occurred in 3% of patients (urinary tract infection, febrile neutropenia, sepsis, pneumonia, cellulitis (type of skin infection), colitis (swelling of the large intestine), diarrhea, osteomyelitis (bone infection), and upper-air passage infection). Life-threatening infections were reported in 2% of patients (sepsis, empyema (collection of pus in a cavity in the body), pneumonia, febrile neutropenia, fever, and biliary stent-associated cholangitis (bile duct infection)).

Please click here to see the full Prescribing Information, including the BOXED WARNINGS, for ZEVALIN. Because ZEVALIN treatment includes the use of rituximab, please see the rituximab medication guide (

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit, or call 1-800-FDA-1088.


Back to top


1. Adult Non-Hodgkin Lymphoma Treatment (PDQ®). National Cancer Institute Web site. Updated February 13, 2015. Accessed March 13, 2015.

2. Non-Hodgkin Lymphoma Overview. American Cancer Society Web site. Updated January 28, 2015. Accessed March 13, 2015.

3. Understanding Non-Hodgkin Lymphoma. Lymphoma Research Foundation Web site. Published 2012. Accessed March 13, 2015.

4. SEER Stat Fact Sheets: Non-Hodgkin Lymphoma. National Cancer Institute Web site. Accessed March 13, 2015.

5. Facts 2014–2015. Leukemia & Lymphoma Society Web site. Published 2015. Accessed March 13, 2015.

6. Cancer Facts & Figures 2015. American Cancer Society Web site. Published 2015. Accessed March 13, 2015.