Non-Hodgkin lymphoma is a type of cancer of the blood cells. It occurs when certain types of white blood cells (lymphocytes) grow in an uncontrolled way. Lymphocytes are part of the immune system that help our bodies fight infection. They include B cells and T cells.
Non-Hodgkin lymphoma can start anywhere in the lymphatic system (the network of vessels, tissues and organs that make white blood cells and move lymph around the body) and can spread throughout the lymphatic system.
There are 3 main types of non-Hodgkin lymphoma that affect children:
- Lymphoblastic lymphoma affects cells called lymphoblasts, which are very early lymphocytes. It can start in the thymus (the organ in the chest that produces T cells), and lymph nodes in the neck and chest, and can spread quickly to other parts of the body.
- Burkitt lymphoma develops from B cells and often starts as a tumour in the abdomen. It can spread quickly to other parts of the body.
- Large cell lymphoma starts in older B cells or T cells anywhere in the body. It is less likely to spread than other forms of lymphoma.
Non-Hodgkin lymphoma occurs more often in older children than in younger children.
A different type of lymphoma that occurs in children is called Hodgkin disease.