Lymphoma is a disease of the lymphocytes. It is like a cancer, in that the affected lymphocytes stop being regulated in the normal way. In other words, they may divide abnormally or too quickly, and/or they may not die off in the way they ought to. The abnormal lymphocytes often collect in the lymph nodes, which become swollen as a result.
Because lymphocytes circulate throughout the body, lymphomas - collections of abnormal lymphocytes - can also form in parts of the body other than the lymph nodes.The spleen and the bone marrow are common sites for lymphomas to form outside the lymph nodes, but some people develop a lymphoma of the stomach, the liver or rarely of the brain. Indeed, a lymphoma can form almost anywhere. It is also common for more than one part of the body to be affected by the disease.
In general, because of the circulatory nature of the lymph, lymphomas are usually referred to as diseases that affect the whole body, and not just the area that is obviously affected by swollen glands. These conditions are known as 'systemic diseases'.
Many of the symptoms of lymphoma arise because of the swellings caused by the collections of abnormal lymphocytes. The precise symptoms depend on where in the body the swellings are. In addition, the abnormal lymphocytes are not able to fulfil their normal role in the body's immune system and, without treatment, a person with lymphoma is likely to become more prone to infection.
Lymphomas can be divided into two main groups:
This website is concerned only with non-Hodgkin's lymphoma.
Non-Hodgkin's lymphoma is one of the two main groups of lymphoma (the other being Hodgkin's lymphoma). The cells in a non-Hodgkin's lymphoma look and behave differently from those in a Hodgkin's lymphoma.
It is important to know exactly what form of non-Hodgkin's lymphoma a patient has, how fast it is developing, where it is in the body, and how far it has spread. To work this out, the disease is subdivided by:
This information - the classification, the type and the stage - helps doctors to predict the way in which a particular non-Hodgkin's lymphoma will behave and how the patient is likely to be affected. It is also very important to plan the correct treatment, so all the information must be available before treatment is planned and started.