Lymphomas are cancers originating from the lymphatic cells of the immune system, typically seen as solid tumours. The lymphatic system is part of the body’s immune system and helps fight infections and other diseases. Because lymphatic tissue is found in many parts of the body, lymphomas can start almost anywhere. In 1832, Thomas Hodgkin, a British pathologist published the first description of lymphoma, a specific form which is named after him as ‘Hodgkin Lymphoma’. Since then many other forms of lymphoma have been described, all grouped under a single label ‘non-Hodgkin lymphoma’. However, the latest lymphoma classification by the WHO (2008) considers the ancient arrangement obsolete because the different lymphomas grouped under NHL have very little in common with each other. Hence the NHL label is slowly being abandoned considering its minimal relevance.
Causes and Risk Factors
The cause of this cancer is unknown for most patients. However, lymphomas may develop in people with a weakened immune system such as in organ transplant patients on immuno suppressive drugs or HIV infection. Certain viruses such as HTLV-1 (Human T Cell Leukemia/ Lymphoma Virus), hepatitis C, and Epstein-Barr virus seem to directly affect the DNA of the lymphocytes and help transform them into cancer cells.
Helicobacter pylori, a type of bacteria known to precipitate stomach ulcers causes chronic immune system stimulation and has been associated with Mucosa Associated Lymphoid Tissue (MALT) lymphoma of the stomach. Although NHL can affect all age groups, the chance of developing this disease increases with age.