Lymphoma is a general term for a group of cancers that originate in the lymphatic system. The lymphomas are divided into two major categories: Hodgkin lymphoma and all other lymphomas, called non-Hodgkin lymphomas. The prefix "lymph-" indicates their origin in the malignant change of a lymphocyte and the suffix "-oma" is derived from the Greek suffix denoting "tumor." About 53 percent of the blood cancers that occur each year are lymphomas.

Hodgkin lymphoma was named for Thomas Hodgkin, an English physician who described several cases of the disease in 1832. Hodgkin lymphoma will represent about 11.5 percent of all lymphomas diagnosed in 2007.

About 71,380 people living in the United States will be diagnosed with lymphoma in 2007. This figure includes approximately 8,190 new cases of Hodgkin lymphoma (4,470 males and 3,720 females), and 63,190 new cases of non-Hodgkin lymphoma (34,200 males and 28,990 females).

Lymphomas result when a lymphocyte (a type of white blood cell) undergoes a malignant change and begins to multiply, eventually crowding out healthy cells and creating tumors that enlarge the lymph nodes or other parts of the immune system.

Lymphomas generally start in lymph nodes or collections of lymphatic tissue in organs like the stomach or intestines. They may involve the marrow and the blood in some cases. Lymphomas may spread from one site to other parts of the body. Lymphocytic leukemias originate and are most prominent in the marrow and spill over into the blood. They occasionally spread to involve the lymph nodes.

<reprinted from http://www.leukemia-lymphoma.org - please visit their site for more information>