The most common types of non Hodgkin lymphoma

There are many different types of non Hodgkin lymphoma. Understanding how different types of NHL are grouped, or classified, is not easy. A variety of systems for classifying lymphomas have been used over the years. The latest is the World Health Organisation classification of 2008. We give a simple description of the groups on this page.

Your doctor will find out which type of non Hodgkin lymphoma you have by taking a lymph node out and sending it to the lab. This is called a biopsy. A specialist doctor called a pathologist examines this under a microscope. Look in the section about diagnosing non Hodgkin lymphoma for more about this. The pathologist will examine the cells to see

• The grade of your NHL
• The type of cell affected (B cell or T cell)
• What the cells look like under a microscope
• Which markers are on the surface of the lymphoma cells (immunohistochemistry)
• If there are certain genetic abnormalities in the lymphoma cells (cytogenetics)

Doctors put non Hodgkin lymphomas into 2 groups depending on how quickly they are likely to grow and spread

• Low grade or indolent (slow growing)
• High grade or aggressive (faster growing)

The different grades of non Hodgkin lymphoma are treated in slightly different ways. Look in the treating non Hodgkin lymphoma section for more information about this.

Your doctor will be able to give your type of non Hodgkin lymphoma a name depending on the appearance of the lymphoma cells. These names are quite complicated. But they are useful to doctors because the different types are known to behave slightly differently. Different treatments are used for the different types. So knowing the type helps the doctor know how to treat them. In the laboratory a pathologist looks at the cells to see if they are

• Large or small
• Grouped together in structures called follicles (follicular type) or spread out (diffuse type)

Low grade non Hodgkin lymphomas tend to have small cells that are grouped together.

Remember that the word diffuse can also be used to describe NHL that is widespread in the body. This is not the same as the diffuse type of NHL called diffuse large B cell lymphoma. As you can see, the classification of lymphoma can be a confusing subject.

• Follicular
• Mantle cell
• Splenic marginal zone lymphoma
• MALT lymphoma
• Lymphoplasmacytic NHL (also called Waldenstrom's macroglobulinaemia)
• Small cell lymphocytic lymphoma (also called chronic lymphocytic leukaemia)

Follicular lymphoma is the most common type of low grade lymphoma. Follicular lymphomas can be divided into 3 separate grades – 1, 2 and 3. Grade 3 is divided into 3A and 3B. The 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.

Small cell lymphocytic lymphoma and chronic lymphocytic leukaemia are the same condition. In theory, lymphoma is an illness that starts in the lymph nodes and 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 most often. Doctors sometimes call it small cell lymphoma when the disease involves the lymph nodes in particular. We have a whole section of information about chronic lymphocytic leukaemia which covers diagnosis, treatment and ways of coping.

• Diffuse large B cell
• Diffuse mixed cell lymphoma
• Burkitt's lymphoma
• Anaplastic large cell lymphoma
• Diffuse mixed cell lymphoma

Diffuse large B cell lymphoma is the most common type of high grade non Hodgkin lymphoma. About a third of people with NHL have this type of lymphoma.

Over time, low grade lymphomas may 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 (10 to 70%), depending on the type they have. So it doesn't always happen. If it does, it may be several years after you were first diagnosed with the low grade lymphoma.

Sometimes, a low grade and higher grade lymphoma can be there at the same time, in the same person. Even in the same lymph node. If this happens, your doctor may assume that it is in the process of transforming to the higher grade type.

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

About 1 in 10 lymphomas (10%) are T cell lymphomas. A rare type of T cell non Hodgkin lymphoma is mycosis fungoides. This is sometimes called cutaneous T cell lymphoma. This means T cell lymphoma that affects the skin. It is a low grade (indolent) type of NHL. It is treated with ultraviolet light treatment, chemotherapy and radiotherapy. There is a page about cutaneous T cell lymphoma in this section. Other types of T cell NHL include large cell anaplastic lymphoma and peripheral T cell lymphoma. These are both high grade (aggressive) types of NHL.

MALT lymphoma is a type of NHL that starts outside the lymphatic system. MALT stands for mucosa associated lymphoid tissue. It is a B cell lymphoma. It means that the lymphoma begins to grow in lymphatic tissue that is found in the lining of other organs. MALT lymphoma is most common in the stomach. It is linked to a bacterial infection called helicobacter pylori. Research over the past few years has discovered that treating the infection with antibiotics can put MALT lymphoma of the stomach into remission. It is too early to say how long the remission lasts. Treating the infection may actually cure this rare type of NHL. There is information about MALT lymphoma on another page in this section.

Mantle cell lymphoma is a rare type of NHL that makes up between 5 and 10 out of every 100 (5 to 10%) of all non Hodgkin lymphomas diagnosed. It most often affects men over the age of 50. It is a B cell lymphoma. Even though mantle cell lymphomas are classed as low grade, they behave aggressively and are often treated more like high grade lymphomas. There is a page about mantle cell lymphoma in this section.