Non-Hodgkin lymphomas are a diverse group of cancers that develop in B or T cells (lymphocytes).
Often, lymph nodes in the neck, under the arms, or in the groin enlarge rapidly and painlessly.
People may have pain or shortness of breath or other symptoms when enlarged lymph nodes press on organs.
A lymph node biopsy is needed for diagnosis.
Treatment may involve radiation therapy, chemotherapy, monoclonal antibodies, or a combination.
Most people are cured or survive for many years.
This group of cancers is actually more than 50 different diseases that involve B cells or T cells (lymphocytes), which are types of white blood cell (see Neutrophilic Leukocytosis). Each of these lymphomas has a distinct appearance under the microscope, a different cell pattern, and a different pattern of symptoms and progression. Most non-Hodgkin lymphomas (85%) are from B cells. Less than 15% develop from T cells. Non-Hodgkin lymphoma is more common than Hodgkin lymphoma. In the United States, about 70,000 new cases are diagnosed every year, and the number of new cases is increasing, especially among older people and people whose immune system is not functioning normally. People who have had organ transplants and some people who have been infected with hepatitis C or the human immunodeficiency virus (HIV) are at risk of developing non-Hodgkin lymphoma.
Although the cause of non-Hodgkin lymphomas is not known, evidence strongly supports a role for viruses in some of the less common types. A rare type of rapidly progressive non-Hodgkin lymphoma, which occurs in southern Japan and the Caribbean, may result from infection with human T-cell lymphotropic virus 1 (HTLV-1), a retrovirus similar to HIV. The Epstein-Barr virus is associated with many cases of Burkitt lymphoma (see Burkitt Lymphoma), another type of non-Hodgkin lymphoma.
Leukemias (see Leukemias) also are cancers that involve white blood cells. In leukemia, most of the cancerous white blood cells are in the bloodstream. In lymphoma, most of the cancerous white blood cells are within lymph nodes and organs such as the spleen and liver. However, leukemia and non-Hodgkin lymphoma sometimes overlap because people with lymphoma may have cancerous white blood cells in their bloodstream and people with leukemia may have leukemia cells in their lymph nodes and organs.