What is Hodgkin lymphoma?
Hodgkin lymphoma is a type of blood cancer that affects white blood cells called lymphocytes. It is also called a cancer of the lymphatic system.
The lymphatic system is a system of thin tubes and lymph nodes that run throughout the body. Lymph nodes are bean shaped glands. The thin tubes are called lymph vessels or lymphatic vessels. Tissue fluid called lymph circulates around the body in these vessels and flows through the lymph nodes.
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.
The diagram below shows parts of the lymphatic system.
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 a microscope. They contain cells called Reed Sternberg cells. Non-Hodgkin lymphomas look different under the microscope and do not contain Reed Sternberg cells.
Reed Sternberg cells are a type of white blood cell called a B lymphocyte, that has become cancerous. B lymphocytes normally make antibodies to help fight infections.
Most lymphomas are non-Hodgkin lymphoma. It's important for doctors to be able to tell the difference between Hodgkin and non-Hodgkin lymphomas. They are two different diseases and the treatment for them is not the same.
This video explains what lymphoma is and how it starts. And the difference between Hodgkin lymphoma and non-Hodgkin lymphoma. The video lasts just over 3 minutes.
What is lymphoma?
Lymphoma is cancer of the lymphatic system.
There are two main types: Hodgkin lymphoma and non-Hodgkin lymphoma - or NHL.
The lymphatic system is part of our immune system it helps us fight infections.
Understanding how it works may help you to understand what lymphoma is.
The lymphatic system is made up of a number of different organs, including the bone marrow, the spleen and the thymus gland.
It’s also made up of thin tubes and lymph nodes which contain lymph fluid.
Lymph nodes are sometimes called lymph glands.
The lymphatic system runs throughout the body.
The lymph nodes filter substances that travel in the lymph fluid.
They also contain lymphocytes, a type of white blood cell that helps us to fight infections.
There are two main types of lymphocytes: B cells and T cells.
They work in slightly different ways.
A lymphoma starts when the lymphocytes become abnormal.
The abnormal cells make more abnormal cells, which means you have many more lymphocytes than usual, but they can’t fight infections as well as they should.
These abnormal cells circulate around the lymphatic system and start to build up in the lymph nodes forming a lump.
You may notice swollen glands in your neck, your armpit, or your groin.
But they can collect in other parts of your body that you can’t feel, including your lungs, liver and spleen.
It's important that your doctor finds out which type of lymphoma you have – Hodgkin lymphoma or non-Hodgkin lymphoma as they are two different diseases.
The most common type of Hodgkin lymphoma is called classical Hodgkin lymphoma.
It starts in B cells and contains Reed-Sternberg cells.
So, finding out if these particular cells are present confirms it's this type of lymphoma.
Non-Hodgkin lymphomas are the more common type of lymphoma.
There are many different types of non-Hodgkin lymphomas and they are grouped into either high grade or low grade.
High grade are faster growing and low grade NHL’s grow more slowly.
Your doctor will tell you the type of lymphoma you have and what this means for you.
It depends on the type of lymphoma you have as to what treatment you need.
You might have drug treatment, radiotherapy, or a stem cell transplant.
For more information about lymphoma, the tests you might have, and treatments visit cruk.org/ about-cancer/lymphoma
Where Hodgkin lymphoma can start
Hodgkin lymphoma can start anywhere in the lymphatic system. It can develop in more than one place in the body at the same time.
The most common place for it to be noticed is in the lymph nodes in the neck. But it can start in any of the lymph nodes in the body. For example; in the chest, groin, abdomen, or armpit.
Body organs
You can also get Hodgkin lymphoma in body organs, such as in the liver, bone or lung.
Some people are diagnosed with Hodgkin lymphoma in their spleen. The spleen is a large organ to the left of your stomach. It is part of the lymphatic system and it helps to filter old or damaged blood cells and fights infection.
Hodgkin lymphoma can occur in either the tonsils or a gland in the chest called the thymus, but this is very rare. Lymphoma in these sites is usually non-Hodgkin lymphoma.
Extranodal disease
If Hodgkin lymphoma is in parts of the body outside the lymphatic system it is called extranodal disease.
Other types of cancer
Remember that it's very common for other types of cancer to spread to lymph nodes. This is not lymphoma. For example, breast cancer can spread to the lymph nodes close to the breast. This means the lymph nodes contain breast cancer cells not lymphoma cells.
For information about cancer that has spread to the lymph nodes you need to look at the section about your cancer type.
Who gets it
In the UK, Hodgkin lymphoma is slightly more common in males than females.
It can happen at any age. It's more common in young adults. It then becomes less common until middle age when it becomes more common again. There's a second peak in older age.
How common it is
Hodgkin lymphoma is rare. Around 2,100 people are diagnosed in the UK each year.
