Find out who gets non Hodgkin lymphoma, where it starts and how common it is.
What non Hodgkin lymphoma (NHL) is
Lymphoma means cancer of the lymphatic system.
The lymphatic system is a system of thin tubes and lymph nodes that run throughout the body. These tubes are called lymph vessels or lymphatic vessels. The lymph system is an important part of our immune system. It plays a role in fighting bacteria and other infections and destroying old or abnormal cells, such as cancer cells.
Hodgkin lymphoma and non Hodgkin lymphoma
There are 2 main types of lymphoma. They are called Hodgkin lymphoma and non Hodgkin lymphoma.
Hodgkin lymphoma was named after the doctor who first recognised it. It used to be called Hodgkin's disease.
Hodgkin lymphomas have a particular appearance under the microscope and contain cells called Reed-Sternberg cells. Non Hodgkin lymphomas look different under the microscope and do not contain Reed-Sternberg cells.
It is important that doctors can tell the difference between Hodgkin and non Hodgkin lymphomas. They are two different diseases. And although they are very similar in many ways, the treatment for them is not quite the same.
There are more than 60 different types of non Hodgkin lymphoma. They can behave in very different ways. Your doctor or specialist nurse will tell you about the type you have.
Where NHL can occur in the body
Because the lymphatic system runs through your whole body, you can get non Hodgkin lymphoma just about anywhere.
It is most commonly noticed first in the lymph nodes in the neck. It is quite common to find it in the liver or spleen. But it can also be found in other body organs, such as the stomach, small bowel, bones, brain, testicles or skin. Although very uncommon, it can also affect the eye.
About 1 in 3 people who have non Hodgkin lymphoma have some lymphoma in an organ outside the lymphatic system. It is then called extranodal disease.
Other cancers that have spread to the lymph nodes
Most types of cancer can spread to the lymph nodes. But they are not lymphoma. Lymphoma is cancer that starts in the lymph nodes.
For example, if breast cancer spreads to the lymph nodes in the armpits it does not become lymphoma. The cancer cells that have spread to the lymph nodes are still breast cancer cells. So they are treated as breast cancer.
Effects on the body
If you have lymphoma, some of your white blood cells (lymphocytes) divide abnormally.
Normal white blood cells have resting time. But if you have lymphoma some of your white blood cells don't have any resting time. This means they divide continuously, so too many are produced. And they don't naturally die off as white blood cells normally do.
These cells start to divide before they are fully mature. So they can't fight infection as normal white blood cells do.
The abnormal white blood cells start to collect in the lymph nodes, or in other places such as the bone marrow or spleen. They can then grow into tumours and begin to cause problems in the lymphatic system, or in the organ in which they are growing. For example, if a lymphoma starts in the thyroid gland it can affect the normal production of thyroid hormones.
B cell and T cell NHL
There are many different types of non Hodgkin lymphoma. These types can be classified in several different ways.
One way is by the type of cell affected. Non Hodgkin lymphoma affects certain white blood cells called lymphocytes. Two types of lymphocyte can be affected – B cells and T cells. So you can have a B cell lymphoma or a T cell lymphoma.
Most people with non Hodgkin lymphoma have B cell lymphomas. T cell lymphomas are more common in teenagers and young adults.
Non Hodgkin lymphoma in children
Non Hodgkin lymphoma is not treated in quite the same way in children as it is in adults. So while some of the information here is useful, you do need to be careful. Check with your doctor which parts apply to you or your child.
How common it is
Around 13,600 cases of non Hodgkin lymphoma are diagnosed each year in the UK. This makes it the 6th most common type of cancer in adults (not counting non melanoma skin cancer). Out of every 100 cancers diagnosed, around 4 (4%) are non Hodgkin lymphomas.
Who gets it
Around 6 out of 10 people (60%) diagnosed with non Hodgkin lymphoma are aged 65 and over.
Non Hodgkin lymphoma is slightly more common in men than in women.