Lymphomas are cancers of the lymphatic system. The lymphatic system is a part of your immune system and helps fight infection. Lymphoma occurs when a type of white blood cell called a lymphocyte starts to grow in an abnormal, uncontrolled way. Healthy lymphocytes collect in the lymph nodes (glands), which are part of your lymphatic system, ready to fight infections.
In lymphoma, the growth of abnormal lymphocytes (lymphoma cells) within the lymph nodes makes the lymph nodes swell. Abnormal lymphoma cells can collect in other places too, such as the spleen, bone marrow, liver, gut or skin. When these areas are affected by lymphoma, they are called ‘extranodal sites’. ‘Extranodal’ means ‘areas outside of the lymph nodes’.
There are 2 groups of lymphomas:
- Hodgkin lymphoma, in which a specific type of cell is found, called a Reed–Sternberg cell. A Reed–Sternberg cell is a type of abnormal B cell that is named after the people who first identified the microscopic changes that are found in Hodgkin lymphoma.
- Non-Hodgkin lymphoma (NHL) is any type of lymphoma that does not contain Reed–Sternberg cells.
These types of lymphoma can behave differently and need different treatment.
Lymphomas are the most common group of cancers in teenagers and young adults (15–24 years old) and the third most common group of cancers in childhood (0–14 years old), after leukaemia and brain tumours.
Every year in the UK, around 150 children and more than 450 teenagers and young people develop lymphoma.
- Both types, but especially Hodgkin lymphoma, are more likely to happen in older rather than younger children.
- In children (0–14 years old), NHL is slightly more common than Hodgkin lymphoma.
- In teenagers and young adults (15–24 years old), Hodgkin lymphoma occurs twice as often as NHL does.
The cause of lymphoma is not yet known but scientists are confident that:
- You can’t catch lymphoma.
- You can’t inherit lymphoma from your parents.
- You can’t pass it on to anyone else.
Children and young people who have congenital immune deficiency or human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) are more likely than other children and young people to develop lymphoma. There are other infections that may increase the risk of developing lymphoma, eg the Epstein-Barr Virus (EBV), which also causes glandular fever. It is important to remember that EBV is a very common virus. About 9 in every 10 adults have been infected with EBV. The vast majority of these people do not have any long-term problems.
Most children and young people in the UK who develop lymphoma were previously fit and well with no other medical problems.
If you are a parent of a child (under 18) with lymphoma, please read the section of our website for parents, which includes more detailed information on Hodgkin lymphoma and NHL in children and practical advice for parents. If you are a young person with lymphoma, we have a section for young people (up to the age of 24) that gives an overview of lymphoma in young people and practical advice for living with lymphoma. You might also want to look at our list of organisations from which you can get further information and support.
Our storybook, Tom has lymphoma, is written and illustrated for younger children (primary school-aged). It is designed for you to read together to help your child understand what lymphoma is and the treatment it involves.
We also produce a young person’s guide to lymphoma. This booklet is designed and illustrated for young people (teens and young adults) affected by lymphoma. You can read this on our website or order a free copy.