Central Nervous System Lympho... Health Article

Definition

Central nervous system (CNS) lymphoma is a malignant growth, or neoplasm, that originates in the white blood cells of the lymphatic fluid in the brain and spinal cord.

Description

CNS lymphoma affects the brain and the spinal cord, the two components of the CNS. The brain and spinal cord work together to control, monitor, and interpret all the physical and mental processes of the body. They make possible the activities a person takes for granted, such as walking, talking, thinking and remembering. A malignancy, or neoplasm, in the brain or spinal cord interferes with the normal functions of the body.

An uncontrolled growth of cells called lymphocytes causes lymphoma. Lymphocytes are the white blood cells in the lymphatic system. Under normal conditions they help the body resist invasion by foreign substances and organisms. In other words, they assist with immune response or defense.

When the uncontrolled growth of lymphocytes originates in the brain or spinal cord, it is called primary CNS lymphoma, or simply, CNS lymphoma. The specific place of origin of CNS lymphoma is probably in cells known as B cells. Other kinds of lymphoma begin elsewhere in the lymphatic system. They may also eventually affect the brain and spinal cord, but they are not called CNS lymphoma.

In most cases, CNS lymphoma does not produce a defined and specific site of growth, or a tumor. Generally, the cancer cells spread throughout the brain and spinal cord. The spread gives way to lesions, which are places where tissue breaks down.

Demographics

Although the number of cases is on the increase, CNS lymphoma is rare. Between 1 and 2% of all uncontrolled growths in the brain result from CNS lymphoma. The most common age of diagnosis in the general population is between 52 and 55 years. However, in patients that have experienced immune system problems, age at diagnosis is much younger, at about 34 years.

Events and conditions that affect the immune system put a person at greater risk for CNS lymphoma. For example, someone who has had an organ transplant is more vulnerable to the disease. Part of the reason is that transplant patients are given drugs to suppress, or reduce, the action of the immune system so their bodies will accept an organ from a donor. Individuals with acquired immunodeficiency syndrome (AIDS) are also at higher risk for CNS lymphoma.

Causes and symptoms

The cause of CNS lymphoma is not known. It is more common in individuals with suppressed immune systems, and individuals with some conditions linked to the X chromosome, one of the two sex chromosomes, seem to be at higher risk. Studies indicate that exposure to certain herbicides also increases risk.

One role of the lymphatic system is to collect fluid that builds up outside cells and to return it to blood vessels. CNS lymphoma obstructs this process. Fluid builds up in the body and puts particular pressure on the cranial nerves, the nerves that carry information directly from the brain to organs such as the eyes and ears. Consequently, symptoms of CNS lymphoma often occur in the organs of the head and in the face.

Symptoms include:

• change in personality
• headache
• nausea and vomiting
• seizures
• weakness
• numbness, particularly in the face
• sensory problems (cannot hear, see)
• difficulty swallowing

Diagnosis

Symptoms cause a person to consult a physician. The initial assessment is made using computed tomography (CT) or magnetic resonance imaging (MRI). To confirm a diagnosis a physician does a variety of tests. They include a physical examination of lymph nodes, chest x ray, blood and urine tests, eye exam, bone marrow biopsy, and—in males—an ultrasound of the testes. Some of the tests are done to rule out other kinds of lymphoma.

Treatment team

CNS lymphoma requires attention from several different types of physician specialists. A neurologist—a physician specializing in the nervous system—does the initial assessment. A radiologist interprets x rays, CT scans, and MRI images. A hematologist or oncologist evaluates the results of blood tests. A pathologist studies the tissue from a biopsy. If there is surgery, and in many cases there is not, the surgery team that removes the tumor typically includes a neurosurgeon and an orthopedic surgeon. The orthopedic surgeon takes part because it is necessary to cut through bone to reach the brain, and maneuver around vertebrae to reach the spinal cord. At premier cancer centers, teams of physicians work collaboratively, with one person (usually an oncologist) taking the lead. Physical and occupational therapists who help with rehabilitation following treatment and surgery, and registered nurses who administer chemotherapy, are also part of the team.