The lymphatic system
The lymphatic system is part of the immune system, which defends the body against infection. The lymphatic system is a network of small lymph nodes connected by very thin lymph vessels, which branch into every part of the body except the brain and spinal cord. The major nodes can be found in the neck, armpits, chest, abdomen, pelvis and groin. Other parts of the lymphatic system include the spleen, thymus and bone marrow.
A clear fluid called lymph flows through the lymph vessels. It contains white blood cells called lymphocytes, special proteins called antibodies, and some waste products. Lymphocytes and antibodies are important parts of your body's immune system. The lymph fluid passes through the lymph nodes, which filter out bacteria and other harmful things.
Lymphoma is a name for cancers of the lymphatic system.
When you have lymphoma, large numbers of abnormal lymphocytes are made. These abnormal lymphocytes replace some of your normal lymphocytes. This can affect your immune system and the way your body fights infections. The lymph nodes also become swollen, forming lumps ( tumours).
There are two main types of lymphoma: non-Hodgkin lymphoma and Hodgkin lymphoma. Some differences are:
- Hodgkin tumours have an abnormal cell called a Reed-Sternberg cell
- the two types of lymphoma spread and are treated differently.
There are different types of non-Hodgkin lymphoma. Indolent lymphomas grow slowly; the commonest type is follicular lymphoma. Aggressive lymphomas grow quickly; the commonest type is diffuse large cell lymphoma.
Causes of lymphoma
The causes of lymphoma are not yet known. There are many different types of lymphoma, and it is likely that there is no single cause of all lymphoma.
Risk factors for lymphoma include exposure to radiation and certain chemicals. For people whose immune system is suppressed, exposure to the human immunodeficiency (AIDS) virus and the Epstein-Barr virus is a risk.
How common is lymphoma?
Non-Hodgkin lymphoma is one of the 10 most common cancers in Victoria. About 1000 Victorians are diagnosed with non-Hodgkin lymphoma every year. These cancers can occur in children; however they are more common in adults.
Hodgkin lymphoma is much less common. About 120 in Victoria are affected each year.
More information on lymphoma from the Leukaemia Foundation
Expert content reviewers:
Assoc. Prof. Jeff Szer, Head, Bone Marrow Transplant Service, Dept of Clinical Haematology & Medical Oncology, Royal Melbourne Hospital