Lymphoma is a cancer of the lymphoid tissue, which is part of the lymphatic system. As a major component of the immune system, the lymphatic system manufactures lymphocytes (a type of white blood cells). It also transports lymph (fluid composed of plasma and a small number of white blood cells) from tissues in the body to the bloodstream. The lymphatic system consists of organs, lymph nodes and lymphatic vessels. Lymphoma is the only form of cancer that originates in the lymphatic system, although other forms of cancer may spread into the system. 

The tissue found in the lymphatic system is formed by various types of immune cells that work together to fight off infection and other threats, such as cancer. In lymphoma, abnormal lymphocytes continue to grown in the lymphoid tissue. This results in an enlargement of the lymph nodes and other organs in the body containing lymphocytes, which in turn causes lumps to develop in the body,

Lymphoma is a cancer of the lymphatic system, which is found all over the body, and which includes circulating lymphocytes. For this reason, the disease easily spreads to tissues throughout the body. Primary central nervous system (CNS) lymphoma is a type of cancer that develops in the lymph tissue in the brain and/or spinal column. It should not be confused with cancers that originate elsewhere in the body and metastasize (spread) to the lymphatic system.

There are two types of lymphoma, each of which begins with distinctly different cells. Hodgkin's lymphoma is a rare form of cancer that is characterized by the presence of specific cells called Reed-Sternberg cells. Non-Hodgkin's lymphoma is far more common and includes all lymphomas not diagnosed as Hodgkin's lymphoma. CNS lymphoma is a type of non-Hodgkin's lymphoma.

Although the causes of CNS lymphoma are unknown, it is known that white blood cells, which are part of the immune system, become malignant. These cells are carried to the central nervous system through the lymph system and blood. When CNS lymphoma continues to grow, the cancer usually does not spread outside of the central nervous system or the eye. 

People with compromised immune systems are at the greatest risk, especially those with immune system diseases or those who have been infected with certain viruses, such as HIV.  Also, heart and other organ transplant patients are at risk because their immune systems are weakened by the anti-rejection medications they take.

Symptoms of CNS lymphoma are similar to those of any brain tumor and may include headaches, seizures, facial paralysis and confusion. The actual symptoms depend on the location of the cancer in the central nervous system. If an initial examination indicates the possibility of CNS lymphoma, a spinal tap, blood tests, imaging tests and bone marrow biopsies may be performed to determine the location and stage of the cancer.

Because CNS lymphoma can be widespread, surgery is not a form of effective treatment. Standard treatment for this type of cancer includes chemotherapy, radiation therapy and steroid therapy. Survival rate or prognosis is determined by the patient’s age, the location and type of tumor and spread of the cancer.

There is no known method of pre-screening for CNS lymphoma or preventing this type of cancer at this time. Although the prognosis is generally poor for patients with CNS lymphoma there have been recent advances in treatment. About 30 percent of people live at least five years with a diagnosis of CNS lymphoma, according to the American Cancer Society.