Low grade NHL

Doctors often group non-Hodgkin lymphoma (NHL) as either low grade or high grade. The grade depends on how quickly the NHL is likely to grow and spread. 

Low grade NHL tends to grow very slowly. Doctors call them indolent lymphomas. High grade lymphomas tend to grow more quickly. Doctors sometimes describe them as aggressive lymphomas. 

This page is about the different types of low grade NHL.

NHL begins in a type of white blood cell called a lymphocyte. There are two types of lymphocytes. These are B cells and T cells. So you can develop a B cell lymphoma or a T cell lymphoma. There are different types of B cell and T cell lymphomas. Some of these are low grade, and some are high grade.

Types of low grade NHL

Follicular lymphoma is the most common type of low grade NHL. Other types include:

  • mantle cell lymphoma
  • marginal zone lymphoma 
  • small lymphocytic lymphoma
  • lymphoplasmacytic lymphoma
  • skin (cutaneous) lymphoma 

Over time, a low grade lymphoma can sometimes change into a high grade type lymphoma. Doctors call this transformation.

Follicular lymphoma

Follicular lymphoma is a type of B cell lymphoma. It is the most common type of low grade lymphoma. Each year around 2,500 people are diagnosed with follicular lymphoma in the UK.

Out of all people with NHL in the UK, just under a fifth (18%) have the follicular type. It mainly affects adults over the age of 60.

Doctors might further sub divide follicular lymphoma into 3 separate grades. To find out your grade, doctors looks at your lymphoma cells under a microscope. 

These are 3 grades -  grade 1, 2 and 3.  Grade 3 is divided into 3A and 3B.  Grade 3B follicular lymphoma is faster growing. Doctors are likely to treat it as a high grade lymphoma.

Mantle cell lymphoma

Mantle cell lymphoma is a rare type of B cell lymphoma.

Each year around 75 people are diagnosed with mantle cell lymphoma in the UK. Out of all people with NHL in the UK, less than 1 in every 100 people (1%) have mantle cell lymphoma.

Mantle cell lymphoma looks like a low grade lymphoma under the microscope. But it often grows more quickly. So doctors might treat it more like a high grade lymphoma.

Marginal zone lymphoma

This is a group of slow growing B cell lymphomas.

It is called marginal zone lymphoma because it starts in an area of lymphoid tissue called the marginal zone. There are different types of marginal zone lymphoma.

Mucosa associated lymphoid tissue (MALT) lymphoma 

This is the most common type of marginal zone lymphoma. You might hear it called extranodal marginal zone lymphoma.

MALT lymphoma does not start in the lymph nodes. It starts in the mucosa. This 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 often 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 marginal zone lymphoma starts within the lymph nodes. It is sometimes called monocytoid B cell lymphoma.

Splenic marginal zone lymphoma 

This type of marginal zone lymphoma starts in the spleen Open a glossary item but can also be found in the bloodstream. 

Primary cutaneous marginal zone lymphoma

This type of marginal zone lymphoma starts in the skin.

Small lymphocytic lymphoma (SLL)

Small lymphocytic lymphoma (SLL) is a slow-growing type of blood cancer. It is the same as another illness called chronic lymphocytic leukaemia (CLL). 

SLL and CLL develop when B cells grow out of control. The abnormal B cells don’t work properly. They build up in different parts of your body.

In CLL, many of the abnormal B cells are in the blood and bone marrow.  So doctors call it leukaemia. In SLL the abnormal lymphocytes are mainly in your lymph nodes. So doctors call it lymphoma. 

Lymphoplasmacytic lymphoma (including Waldenstrom's macroglobulinaemia)

Lymphoplasmacytic lymphoma (LPL) is a type of slow growing NHL. It starts in B cells. The B cells become abnormal and grow out of control. They fill up the bone marrow or enlarge the lymph nodes or spleen Open a glossary item.

Doctors call this lymphoma 'lymphoplasmacytic' because the abnormal lymphocytes Open a glossary item also have plasma cell Open a glossary item features. 

The most common type of LPL is called Waldenstrom's macroglobulinaemia (or immunocytoma). The abnormal cells can produce large amounts of abnormal antibodies. Open a glossary item People with Waldenstrom's macroglobulinaemia have a high level of abnormal antibody called immunoglobulin M (IgM) in their blood. This makes the blood thicker.

The treatment for all types of LPL is the same.

Skin lymphoma

Skin (cutaneous) lymphoma is a rare type of NHL. It starts in white blood cells called lymphocytes Open a glossary item

There are 2 types of lymphocytes: T cells and B cells. Skin lymphoma can start in either T cells or B cells. So there are 2 main types of skin lymphoma:

  • cutaneous T cell lymphoma (CTCL) starts in the T cells of the skin
  • cutaneous B cell lymphoma (CBCL) starts in the B cells of the skin

CTCL is the most common type of skin lymphoma. It causes flat red patches on the skin that look like eczema and can be itchy. It can affect several parts of the body.

CBCL is rarer. People tend to have lumps on their skin in 1 or 2 areas, rather than affecting all of the body. 

Transforming from low grade to high grade

Over time, low grade lymphomas can sometimes change into a faster growing (high grade) lymphoma. Doctors call this transformation.

Transformation is more common in some types of NHL than others. So it does not always happen. Most low grade lymphomas do not transform. If lymphoma does transform it can happen any time. Sometimes, it can happen many years after you are first diagnosed with low grade NHL.

Sometimes, you can have a low grade and high grade lymphoma at the same time. Your doctor might assume that your low grade lymphoma is in the process of transforming to the higher grade type.

After a low grade NHL has transformed, the doctors treat it as high grade. Unfortunately, a transformed NHL is generally harder to control than when it was low grade. And the treatment is more intense.

Treatment for low grade lymphomas

The type of treatment you have for low grade (indolent) NHL depends on:

  • the stage Open a glossary item and type of your lymphoma when it is diagnosed
  • the symptoms you have at the time
  • your general health and fitness

Your doctor might decide not to give treatment if you don't have any symptoms when you are diagnosed. Instead, they keep a close eye on you. You might hear this called watch and wait.

The main types of treatment for NHL are:

  • chemotherapy
  • targeted cancer drugs
  • radiotherapy 

We have treatment information for some of the different types of low grade lymphoma. You can look for your lymphoma type at the link below.

  • The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms
    R Allagio and others
    Leukemia. 2022. Volume 36, Issue 7, Pages 1720-1748

  • Guideline for the diagnosis and management of marginal zone lymphomas: A British Society of Haematology Guideline
    R Walewska and others
    British Journal of Haematology 2024.  Volume 204, Issue1, Pages 86-107

  • Diagnosis and management of mantle cell lymphoma: A British Society of Haematology Guideline
    T Eyre and others
    British Journal of Haematology 2024.  Volume 204, Issue1, Pages 108-126

  • The investigation and management of follicular lymphoma
    C Mcnamara and others
    British Journal of Haematology, 2020. Volume191, Issue3, Pages 363-381

  • ESMO Consensus Conference on Malignant Lymphoma: General Perspectives and Recommendations for Prognostic Tools in Mature B-cell Lymphomas and Chronic Lymphocytic Leukaemia
    M Ladetto and others 
    Annals of Oncology, 2017. Volume 27, Pages 2149–2160.

  • The incidence data were compiled by the Statistical Information Team at Cancer Research UK using data from the Office for National Statistics and the regional cancer registries in Wales, Scotland and Northern Ireland using the latest data for 2017. 

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
23 Feb 2024
Next review due: 
23 Feb 2027

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