Non-Hodgkin lymphoma is a type of lymphoma, which is a general term for cancers that develop in the lymphatic system. It is sometimes called non-Hodgkin’s lymphoma.
When types of white blood cells called lymphocytes become damaged, they grow abnormally and multiply uncontrollably, causing enlarged lymph nodes and painless lumps called tumours. As these damaged lymphocytes replace normal lymphocytes, the body’s immune system becomes less able to fight infections. This is how non-Hodgkin lymphoma develops.
Non-Hodgkin lymphoma can occur in one lymph node, a group of lymph nodes, or an organ such as the liver or spleen. It is sometimes found in several parts of the body at the same time.
Topics on this page:
- The lymphatic system
- Types of non-Hodgkin lymphoma
- What causes non-Hodgkin lymphoma?
- Who gets non-Hodgkin lymphoma?
The lymphatic system
Non-Hodgkin lymphoma is a cancer that starts in the lymphatic system. The lymphatic system is a key part of the immune system, which helps protect the body against disease and infection.
The lymphatic system includes a large network of thin tubes called lymph vessels that are found throughout the body and in a number of organs, such as the spleen, liver, thymus gland and bone marrow.
Lymph vessels carry a clear fluid called lymph, which travels to and from the tissues in the body before being emptied into the bloodstream. Lymph fluid contains white blood cells called lymphocytes, which help fight infection. The two main types of lymphocytes, B-cells and T-cells, are produced in the bone marrow. Non-Hodgkin lymphoma starts in these B-cells and T-cells.
Along the lymph vessels is a network of small, bean-shaped structures called lymph nodes or glands. Lymph nodes are found throughout the body, including in the neck, underarms, chest, abdomen and groin.
Lymphocytes in the lymph nodes clean the lymph fluid as it passes through the body by removing and destroying bacteria, viruses and other harmful substances. When germs become trapped in the lymph nodes, the lymph nodes swell, which is a sign that the lymphocytes have multiplied to fight off the germs. For example, the glands in your neck may swell when you have a sore throat.
Other parts of the lymphatic system
The lymphatic system also includes the following organs and tissues:
Spleen – The spleen is found on the left side of the abdomen, under the ribs. It stores lymphocytes, filters waste products from the blood, and destroys old cells, abnormal cells and bacteria.
Thymus gland – This is found inside the rib cage, behind the breastbone. The thymus gland helps produce lymphocytes.
Tonsils – The tonsils are a collection of lymphatic tissue at the back of the throat that traps inhaled or ingested germs.
Bone marrow – This is the soft, spongy material inside the bones. Bone marrow produces three types of blood cells: oxygen-carrying red blood cells; infection-fighting white blood cells, including lymphocytes; and platelets, which help the blood to clot.
Types of non-Hodgkin lymphoma
There are many different types of non-Hodgkin lymphoma.
It can be classified according to whether the cancer started in the B-cells or T-cells of lymphocytes. The table below describes some of the more commonly diagnosed types of non-Hodgkin lymphoma.
|diffuse large B-cell||
a fast-growing cancer that starts in lymph nodes in the neck, armpit or groin
cancer cells grow slowly in lymph nodes in circular groups called follicles
a slow-growing cancer that is similar to chronic lymphocytic leukaemia
develops in the outer edge (mantle zone) of B-cells in the lymph nodes
|precursor T-lymphoblastic||starts in immature (precursor) T-cells in the lymph nodes and the spleen|
|peripheral T-cell||often occurs as widespread enlarged, painless lymph nodes in the neck, armpit or groin|
|cutaneous T-cell||primarily affects the skin and starts as red, scaly patches or raised bumps that can be itchy|
What causes non-Hodgkin lymphoma?
In most cases of non-Hodgkin lymphoma, the cause is unknown. However, there are some factors that can increase the risk of the disease:
Immune system deficiency – The immune system is weakened in people with HIV and those taking medicines called immunosuppressants. These include drugs to treat HIV and those that are given to people after an organ transplant. People with autoimmune diseases, such as rheumatoid arthritis and coeliac disease, also have a weakened immune system.
Infections – Some infections can slightly increase the risk of non-Hodgkin lymphoma. These include HTLV-1 (human T-lymphotropic virus 1), Helicobacter pylori, Epstein-Barr virus infection and human herpesvirus 8.
Many people with known risk factors don’t develop non-Hodgkin lymphoma, and some people who do get it have no known risk factors. Non-Hodgkin lymphoma is not contagious.
Who gets non-Hodgkin lymphoma?
Each year in NSW, about 1400 people are diagnosed with non-Hodgkin lymphoma. Most cases of non-Hodgkin lymphoma occur in adults aged 60 and older. However, it can also occur in young adults and children.