Lymphoma is cancer that begins in a specific part of the immune system known as the lymph system. Lymphoma starts in lymphocytes, a type of white blood cell.
There are many types of lymphoma. One type is Hodgkin disease. All the other types of lymphoma fall under the umbrella term, non-Hodgkin’s lymphomas. The cancer cells in Hodgkin disease behave, spread and respond to treatment differently than cancer cells in non-Hodgkin’s lymphomas.
Medical professionals further categorize non-Hodgkin lymphomas as indolent, slow growing or aggressively fast growing. Each of these subtypes also behaves and responds to treatment differently. Lymphoma can develop in adults and children. Lymphoma therapy approaches and prognosis depend on the type of lymphoma and the extent to which the cancer has developed.
Like other cancers, lymphoma causes unhealthy cells to develop in a particular organ. In its early stages, lymphoma affects white blood cells inside lymph nodes, which are small glands located in various places around the body. In its later stages, lymphoma can affect organs far from the lymph node where it originated.
Symptoms of Lymphoma
Symptoms of Hodgkin disease and non-Hodgkin lymphoma are similar. Both cause:
- Painless swelling of lymph nodes in the neck, armpits or groin
- Unintentional or unexplained weight loss
- Night sweats
- Coughing or trouble breathing
Other symptoms of non-Hodgkin lymphoma can include persistent weakness and tiredness, abdominal pain, swelling or fullness.
An enlarged lymph node is often the first sign of Hodgkin disease. In addition to other symptoms associated with lymphoma, people with Hodgkin disease may also experience loss of appetite and itchy skin.
Causes of Lymphoma
Non-Hodgkin’s lymphoma occurs when the body produces too many lymphocytes. In healthy people, lymphocytes have a life cycle — old lymphocytes die and the body creates new white blood cells to take their place. In patients with lymphoma, however, these lymphocytes do not die. This creates an excess of lymphocytes, which begin to crowd in the lymph node, causing swelling.
Hodgkin’s disease can start in one of two types of cells in the immune system: B cells or T cells. B cells produce antibodies that neutralize foreign invaders to fight infection. T cells kill these foreign invaders directly.
Most cases of non-Hodgkin’s lymphoma and Hodgkin’s disease start in B cells, although some subtypes of non-Hodgkin’s lymphoma starts in T cells. Lymphoma begins when a B cell develops a mutation in its DNA that tells the cell to continue living — and start dividing rapidly — instead of dying like a healthy cell. The mutation causes an overabundance of B cells in the lymph node.