Lymphoma is a group of blood cancers that start in the lymphatic system. The lymphatic system carries lymph, a watery, colorless fluid and white blood cells throughout body through a system of vessels. The primary job of the lymph system is to fight infection inside the body by filtering out viruses, microbial bacterium and other harmful agents.
When lymphoma occurs, the white blood cells within the lymph fluid, called lymphocytes, are in a state of uncontrollable growth and multiplication. These cancerous cells can then spread to other parts of the body by moving through the lymphatic system.
There are two main types of lymphoma, Hodgkin's lymphoma (sometimes called Hodgkin’s disease and named for Dr. Thomas Hodgkin who first described it in 1832) and non-Hodgkin's lymphoma (NHL). Each type has characteristics that are similar and those that are so unique as to distinguish it from other diseases classified as lymphoma.