A relatively unknown yet deadly cancer has become more common in the last few decades and is now the sixth most common cancer in the United States, according to the National Cancer Institute. NHL has increased 75 percent over the last 20 years, making it the most rapidly rising cancer after lung cancer and melanoma, NCI says. Cancers of the Immune System NHL is a collection of more than a dozen different cancers of the lymphatic system, which generates the body's immune defenses. These cells also cluster in areas that serve as gateways to the body, including the mucous membranes lining the respiratory and digestive tracts, and the skin.
Lymphocytes travel in the bloodstream, as well.
The lymphatic system also includes such organs as the spleen, thymus and tonsils. Because NHL can develop wherever in the body lymphocytes can be found, the cancer can crop up nearly anywhere. Symptoms can vary widely, depending on the cancer site. The most common symptom is a noticeable, usually painless swelling of a lymph node. If the brain is involved, patients may have headaches, vision changes, or seizures.