What is Non-Hodgkin's Lymphoma?

Lymphoma refers to a cancer of the lymphatic system. The lymphatic system is a network of nodes (knots of tissue) connected by vessels. The lymphatic system's largest organ is the spleen. Together, they drain fluid and waste products from all the organs and structures of your body. The lymph nodes act as tiny filters, straining out invading organisms and cancerous cells.
Lymphocytes, a type of white blood cell that attacks infectious invaders, such as bacteria, viruses, and fungi, destroy most infections before they can enter the bloodstream. When the lymphatic system is fighting an active infection, you may notice that some of your lymph nodes and tissue in the area of the infection become swollen and tender. This is normal.
Lymphoma occurs when the lymph-node cells or the lymphocytes begin to multiply uncontrollably, producing cancerous cells that have the abnormal capacity to invade other tissues throughout your body. The two main types of lymphoma are Hodgkin's lymphoma and non-Hodgkin's lymphoma, which are classified by certain unique characteristics of the cancer cells.