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Low grade NHL

Follicular lymphoma, mantle cell lymphoma and marginal zone lymphoma are all types of low grade non Hodgkin lymphoma (NHL). Read more about the different types. 

Low grade NHL tends to grow very slowly. Doctors call them indolent lymphomas. 

Types of low grade NHL include:

  • follicular lymphoma
  • mantle cell lymphoma
  • marginal zone lymphoma
  • small lymphocytic lymphoma
  • lymphoplasmacytic lymphomas
  • skin lymphomas

Over time, low grade lymphomas may change into a high grade type lymphoma. 

Follicular lymphoma

Follicular lymphoma is the most common type of low grade lymphoma. About a quarter of lymphomas (25%) in the UK are the follicular type.

Follicular lymphoma is a type of B cell lymphoma. It mainly affects adults over the age of 50. They usually have a protein called CD20 on their cell surface. CD20 can be a target for some types of cancer treatment. 


Follicular lymphomas can be divided into 3 separate grades – 1, 2 and 3. Grade 3 is divided into 3A and 3B. These grades are based on how the lymphoma cells look under the microscope.

There is a lot of discussion amongst doctors about whether grading for follicular lymphoma is accurate. It can be difficult to tell the difference between different types of lymphoma cells. Grade 3B follicular lymphoma is faster growing and is likely to be treated as a high grade lymphoma.

Mantle cell lymphoma

Mantle cell lymphoma is a type of B cell lymphoma.

This rare type makes up between 5 and 10 out of every 100 (5 to 10%) non Hodgkin lymphomas diagnosed. It most often affects people in their 50s and 60s.

Even though mantle cell lymphomas are classed as low grade, they might grow quickly. So they might be treated more like high grade lymphomas.

Marginal zone lymphoma

This is a group of slow growing B cell lymphomas. They account for about 12 out of 100 B cell lymphomas (12%). They tend to affect people over the age of 60.

There are 3 types of marginal zone lymphoma.

MALT lymphoma

This is the most common type of marginal zone lymphoma. It makes up about 7 out of 100 B cell lymphomas (7%) in the UK. You might also hear it called extranodal marginal zone lymphoma or mucosa associated lymphoid tissue lymphoma.

MALT lymphoma does not start in the lymph nodes. It starts in the mucosa, which is a soft, moist tissue layer that protects and covers organs in different parts of your body. 

The most common place for it to develop is the stomach. This is called gastric MALT lymphoma.

Less commonly, it can develop in the small bowel, salivary gland, thyroid gland, tear glands or lungs. These lymphomas tend not to spread beyond the place where they started.

Nodal marginal zone lymphoma

This type of lymphoma happens within the lymph nodes. It makes up about 2 out of 100 B cell lymphomas (2%). It tends to affect people over the age of 60 and is very slightly more common in women than men. It is sometimes called monocytoid B cell lymphoma.

Splenic marginal zone lymphoma 

This type starts in the spleen and can also be found in the bloodstream. It makes up about 1 out of 100 B cell lymphomas (1%). It usually affects people over the age of 50.

Small lymphocytic lymphoma

Small lymphocytic lymphoma makes up about 6 out of 100 lymphomas in the UK (6%). It is also called chronic lymphocytic leukaemia (CLL).

In theory, lymphoma is an illness that starts in the lymph nodes whereas leukaemia is an illness of the blood. But leukaemia and lymphoma have many similarities and often affect the body in similar ways.

Chronic lymphocytic leukaemia is the term used for this condition if many of the abnormal cells are in the blood. Doctors call it small lymphocytic lymphoma when the disease involves the lymph nodes in particular.

Lymphoplasmacytic lymphoma (including Waldenstrom's macroglobulinaemia)

In these low grade lymphomas, abnormal B cells fill up the bone marrow or enlarge the lymph nodes or spleen.

Most of these lymphomas are a type called Waldenstrom's macroglobulinaemia (or immunocytoma). This type makes up less than 2 out of 100 B cell lymphomas (less than 2%). It usually affects people over the age of 65 and is slightly more common in men than women.

People with Waldenstrom's macroglobulinaemia have a high level of a protein called immunoglobulin M (IgM) in their blood. The protein makes the blood thicker.

Skin lymphoma

One rare type of non Hodgkin lymphoma is called mycosis fungoides. It affects the skin. It is also called cutaneous T cell lymphoma.

Transforming from low grade to high grade

Over time, low grade lymphomas might change into a more aggressive high grade type lymphoma. This can happen to between 10 and 70 out of every 100 people diagnosed with NHL (between 10% and 70%), depending on the type they have. So it doesn't always happen. If it does, it might be several years after you were first diagnosed with the low grade lymphoma.

Sometimes, you can have a low grade and higher grade lymphoma at the same time. This can even happen in the same lymph node. Your doctor might assume that your low grade lymphoma is in the process of transforming to the higher grade type if this happens.

After a low grade non Hodgkin lymphoma has transformed, it has to be treated as high grade. Unfortunately, a transformed non Hodgkin lymphoma is generally harder to control than when it was low grade. And the treatment is more intense.

Last reviewed: 
01 Sep 2014
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