Non-Hodgkin lymphoma is a cancer in the lymphoid tissue, the disease and infection-fighting system that includes the lymph nodes, spleen, tonsils, and the thymus. The disease gets its name from Dr. Thomas Hodgkin, who first described seven patients with enlarged lymph nodes and spleen in 1832. Later, microscopic examination of tissues from some of the patients ultimately led to the categorization of malignant lymphoma as either Hodgkin or non-Hodgkin lymphoma. Differentiating the two types of lymphoma is important, because the diseases are treated differently.
Non-Hodgkin lymphoma begins inside the lymphocytes—white blood cells that are contained in the lymph nodes, bone marrow, and spleen. While other cancers generally can spread to the lymph nodes, they are not classified as lymphomas. Cancers are classified not by where they spread (or metastasize), but by the organ or tissue of origin.
Lymphomas can arise from either B lymphocytes or T lymphocytes. Among other functions, B lymphocytes fight germs by producing antibodies, and T lymphocytes destroy virus-infected cells. As non-Hodgkin lymphoma progresses, the body's immune system is compromised and less able to fight infection.
The National Cancer Institute estimates there will be more than 65,500 new cases of non-Hodgkin lymphoma and more than 20,200 non-Hodgkin lymphoma-related deaths by the end of 2010.
Symptoms & Risk Factors
Common symptoms of non-Hodgkin lymphoma include:
- unintentional weight loss
- excessive sweating (especially at night)
- swollen lymph nodes in the neck, underarms, groin, and other areas
There is no known cause for non-Hodgkin lymphoma, but several risk factors have been identified. Those most at risk for developing the disease are people over the age of 60 and people with weakened immune systems from HIV or other infections or organ transplants.