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.
B cell NHL is more common than T cell NHL.
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
Low grade lymphomas 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 2,300 people are diagnosed with follicular lymphoma in the UK.
Out of all people with NHL in the UK, around 20 in 100 (around 20%) have follicular NHL. It mainly affects adults over the age of 60 but can occur at any age.
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 600 people are diagnosed with mantle cell lymphoma in the UK. Out of all people with NHL in the UK, around 5 in every 100 people (around 5%) 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. Each year around 2600 people are diagnosed with marginal zone lymphoma in the UK.
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 subtype of marginal zone lymphoma. You might hear it called extranodal marginal zone lymphoma. More than 60 out of 100 (more than 60%) of marginal zone lymphomas are MALT lymphomas.
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. Less than 10 in 100 marginal zone lymphomas (less than 10%) are this type.
Splenic marginal zone lymphoma
This type of marginal zone lymphoma starts in the 
but can also be found in the bloodstream. Around 20 out of 100 marginal zone lymphomas (around 20%) are splenic marginal zone lymphomas.
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 very similar to another illness called chronic lymphocytic leukaemia (CLL).
Around 4,700 people are diagnosed with SLL or CLL in the UK each year.
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 .
Doctors call this lymphoma 'lymphoplasmacytic' because the abnormal also have features.
The most common type of LPL is called Waldenstrom's macroglobulinaemia. In the UK, around 400 people are diagnosed with Waldenstrom's macroglobulinaemia each year.
The abnormal cells can produce large amounts of abnormal 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 .
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. It is rare. Only around 150 people are diagnosed with CTCL in the UK each year.
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
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. The majority of people with low grade NHL do not experience transformation.
If lymphoma does transform it can happen any time. Sometimes, it can happen early on in your illness. And it can also 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 and type of your lymphoma when it is diagnosed - the symptoms you have at the time
- your general health and fitness
Your healthcare team 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 or active surveillance. Some people on active surveillance never need treatment. Other people need to start treatment when their NHL progresses or symptoms get worse.
The main types of treatment for NHL are:
- chemotherapy
- targeted cancer drugs
- radiotherapy
You might have chemotherapy combined with a targeted immunotherapy drug. This is called chemoimmunotherapy.
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.
