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Non-Hodgkin lymphoma

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Follicular lymphoma

Follicular lymphoma is the second most common type of non-Hodgkin lymphoma (NHL). Follicular lymphoma accounts for about 22% of all non-Hodgkin lymphomas. It is a B-cell type of lymphoma. Follicular describes how the lymphoma cells group together in clusters in a lymph node or other tissues.

Follicular lymphoma is usually a slow-growing (indolent) type of lymphoma. It is the most commonly occurring indolent lymphoma. Follicular lymphoma usually occurs in adults 50 years of age or older and is not common in young people.

Follicular lymphoma rarely occurs in only one lymph node area in the body. Often many lymph node areas in the body contain lymphoma and most people with follicular lymphoma are diagnosed with advanced stage disease. The lymphoma has often spread to bone marrow and the spleen, but other extranodalextranodalOf or affecting an area or organ outside the lymph nodes. sites are rarely affected. Sometimes follicular lymphomas can change (transform) into a fast-growing (aggressive) diffuse large B-cell lymphoma (DLBCL). In this case, the treatment is the same as for a diffuse large B-cell lymphoma.

About 80–90% of follicular lymphomas contain a rearrangement of the BCL2 (Bcl-2) gene and a translocation between chromosomes 14 and 18 [t (14;18)]. (A translocation occurs when segments of one chromosome break off and attach to a different chromosome.) These changes cause large amounts of a protein called BCL2 to be made. This protein interferes with the natural death of cells (apoptosis) and may influence how follicular lymphoma responds to treatment.

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Grades of follicular lymphoma

The WHO classifies follicular lymphoma into 3 different grades based on how the lymphoma cells look under the microscope and the number of large cells (centroblasts) per high-power field (hpf) of magnification.

Grade of follicular lymphomaDescription

grade 1

mostly small cells with a folded or indented (cleaved) nucleusnucleusThe part of the cell that holds the chromosomes, which contain DNA (genetic information).

0–5 large cells (centroblasts)/hpf

grade 2

a mixture of small and large cell types

6–15 centroblasts/hpf

grade 3

contains mainly large cells

more than 15 centroblasts/hpf

Grade 1 and 2 follicular lymphomas are often slow growing. Grade 3 follicular lymphoma is the fastest growing and is sometimes treated like a high-grade lymphoma.

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Prognostic factors

Follicular lymphoma has its own prognostic factor index. It is called the Follicular Lymphoma International Prognostic Index (FLIPI). FLIPI helps identify people with follicular lymphoma who have good prognostic factors and are likely to respond well to treatment. It also recognizes those with poor prognostic factors whose lymphoma is likely to relapse. Healthcare professionals consider these factors when they look at treatment options.

FLIPI prognostic factors
Prognostic factorGoodPoor


60 or younger

over 60


I or II



120 g/L or higher

less than 120 g/L

number of lymph node areas involved

4 or less

more than 4


normal LDH

LDH above normal

People with follicular lymphoma are also assigned a point for each poor prognostic factor, which are added for a score of 0 to 5. People with good prognostic factors and a lower score have a better prognosis compared to those with higher scores and 3 or more poor prognostic factors.

Generally, follicular lymphomas grow slowly and a person can live for several years with this type of lymphoma.

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There are many treatment options for follicular lymphoma. Treatment options vary depending on:

  • the extent of disease
  • symptoms a person has
  • a person’s age
  • other prognostic factors

Even though it grows slowly, standard treatments usually do not cure follicular lymphoma. It can be controlled for many years.

Many people with follicular lymphoma will relapse after treatment. The lymphoma often responds to retreatment and the person will have a remission, but the following remissions often become shorter with every course of treatment.

Radiation therapy

External beam radiation therapy is used to treat lymph node areas in localized stage I or stage II follicular lymphoma. This may be referred to as involved field radiation therapy (IFRT). It is not common to have follicular lymphoma in only one lymph node area in the body. Only about 10–15% of people have stage I or II follicular lymphoma.

Radiation therapy may also be used to help reduce symptoms when follicular lymphoma is more advanced.

Watchful waiting

People with more advanced stage follicular lymphoma may not need to be treated right away if they do not have symptoms or problems caused by the lymphoma. The person is observed and treatment is not started until the follicular lymphoma starts to cause symptoms or the lymphoma starts to grow quickly.


Chemotherapy may be used for follicular lymphoma, especially if it has spread to several groups of lymph nodes or other organs and is causing symptoms. Single chemotherapy drugs or a combination of drugs may be used, including:

  • chlorambucil (Leukeran) – may be given with or without prednisone (Deltasone)
  • fludarabine (Fludara) – may be given alone or combined with other drugs
  • CVP – cyclophosphamide (Cytoxan, Procytox), vincristine (Oncovin) and prednisone
  • CHOP – cyclophosphamide, doxorubicin (Adriamycin), vincristine and prednisone

Chemotherapy is commonly used in combination with biological therapy. The most common regimen is CVP and rituximab (Rituxan) or CVP-R.

A drug called bendamustine (Treanda) is somewhat similar to the chemotherapy drug mechlorethamine (nitrogen mustard, Mustargen). It may also be used to treat people with follicular lymphoma as second-line therapy or if the person is no longer responding to other therapies (refractory).

Biological therapy

Monoclonal antibodies are a type of biological therapy that is effective in treating certain types of NHL. Rituximab may be used alone or in combination with chemotherapy to treat follicular lymphoma. Studies have shown that adding rituximab to chemotherapy helps improve the response to chemotherapy and prolong remission.

Newer monoclonal antibodies that carry radioactive substances (radiolabelled monoclonal antibodies) are also possible treatment options. Ibritumomab (Zevalin) may be used in certain people with follicular lymphoma. However, the published data shows radiolabelled monoclonal antibodies have only slightly better results than conventional treatment.

Stem cell transplant

A stem cell transplant (SCT) may be an option for some people if their lymphoma relapses or recurs after treatment.

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For more detailed information on specific drugs, go to sources of drug information.


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