Primary CNS Lymphoma

Lymph system; drawing shows the lymph vessels and lymph organs including the lymph nodes, tonsils, thymus, spleen, and bone marrow. One inset shows the inside structure of a lymph node and the attached lymph vessels with arrows showing how the lymph (clear fluid) moves into and out of the lymph node. Another inset shows a close up of bone marrow with blood cells. Source: NCI

Primary central nervous system (CNS) lymphoma is a disease in which malignant (cancer) cells form in the lymph tissue of the brain and/or spinal cord. The lymph system is part of the immune system and is made up of the lymph, lymph vessels, lymph nodes, spleen, thymus, tonsils, and bone marrow. Lymphocytes (carried in the lymph) travel in and out of the central nervous system (CNS). It is thought that some of these lymphocytes become malignant and cause lymphoma to form in the CNS. Primary CNS lymphoma can start in the brain, spinal cord, or meninges (the layers that form the outer covering of the brain). Because the eye is so close to the brain, primary CNS lymphoma can also start in the eye (called ocular lymphoma).

Other Names

Primary CNS lymphoma has been called many other names:

• primary brain cancer
• microglioma
• reticulum cell sarcoma
• diffuse histiocytic lymphoma

Symptoms

Some symptoms of primary CNS lymphoma include the following:

• headache
• seizures
• fever
• night sweats
• psychological changes
• dementia
• weight loss
• stupor

Causes

Primary CNS lymphoma results from the proliferation of B cells (or lymphocytes) that collect in distinct regions of the brain, especially around blood vessels. The cancer is more prevalent in people with compromised immune systems, such as people with acquired immune deficiency syndrome (AIDS). Why the cancer develops in people with or without healthy immune systems is not known.

Diagnosis

Many different exams and tests are used in the diagnosis of primary CNS lymphoma.

Physical exams and medical histories

Physical exams and medical histories are used to check general signs of health and symptoms of disease. Medical histories, including health habits and past illnesses and treatments, are also considered.

Neurological exams are a series of questions and tests to check the brain, spinal cord, and nerve function. The exam checks a patient's mental status, coordination, ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro exam or a neurologic exam.

Because primary CNS lymphoma can affect the eyes, a slit-lamp eye exam I used to examine the inside and outside of the eye. This exam uses a special microscope with a bright, narrow slit of light. Sometimes a vitrectomy is done. In this procedure, some or all of the vitreous humor (the gel-like fluid inside the eyeball) is removed and viewed under a microscope by a pathologist to check for cancer cells.

Medical Imaging

CT scans (CAT scan) make a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. For primary CNS lymphoma, a CT scan is done of the chest, abdomen, and pelvis (the part of the body between the hips).

An MRI (magnetic resonance imaging) uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the brain and spinal cord. A substance called gadolinium is injected into the patient through a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).

Tissue Sampling

Lumbar punctures are used to collect cerebrospinal fluid (the fluid in the spaces around the brain and spinal cord) from the spinal column. These punctures are done by placing a needle into the spinal column. This procedure is also called an LP or spinal tap. Laboratory tests to diagnose primary CNS lymphoma may include checking the protein level in the cerebrospinal fluid.

Stereotactic biopsies use a computer and a 3-dimensional (3-D) scanning device to find a tumor site and guide the removal of tissue so it can be viewed under a microscope to check for signs of cancer.

Complete blood count (CBC) is a procedure in which a sample of blood is drawn and checked for the following:

• number of red blood cells and platelets
• number and type of white blood cells
• amount of hemoglobin (the protein that carries oxygen) in the red blood cells
• portion of the blood sample made up of red blood cells

Complete blood count (CBC). Blood is collected by inserting a needle into a vein and allowing the blood to flow into a tube. The blood sample is sent to the laboratory and the red blood cells, white blood cells, and platelets are counted. The CBC is used to test for, diagnose, and monitor many different conditions.

Bone marrow tests, including a bone marrow aspiration and biopsy, are used to take Samples of blood, bone, and bone marrow for examination under a microscope.

Blood Chemistry

Blood chemistry studies are used to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.

Expected Outcome

The prognosis depends on the following:

• age and general health
• the level of certain substances in the blood and CSF
• location of tumor
• whether the person has AIDS

Treatment

Treatment options depend on the following:

• stage of the cancer (which is the extent and amount of spread of the cancer)
• location of the tumor
• age and general health
• whether the cancer is newly diagnosed or recurrent (come back).

Treatment of primary CNS lymphoma works best when the tumor has not spread outside the cerebrum (the largest part of the brain) and the patient is younger than 60 years, able to carry out most daily activities, and does not have AIDS or other diseases that weaken the immune system.

There are different types of treatment for patients with primary CNS lymphoma. However, surgery is not used to treat primary CNS lymphoma. Instead, the following treatments are used:

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type of cancer being treated.

High- dose radiation therapy to the brain can damage healthy tissue and cause disorders that can affect thinking, learning, problem solving, speech, reading, writing, and memory. Clinical trials have tested the use of chemotherapy alone or before radiation therapy to reduce the damage to healthy brain tissue that occurs with the use of radiation therapy.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column (intrathecal chemotherapy), an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type of cancer being treated. Primary CNS lymphoma may be treated with intrathecal chemotherapy and/or intraventricular chemotherapy, in which anticancer drugs are placed into the ventricles (fluid -filled cavities) of the brain.

A network of blood vessels and tissue, called the blood-brain barrier, protects the brain from harmful substances. This barrier can also keep anticancer drugs from reaching the brain. In order to treat CNS lymphoma, certain drugs may be used to make openings between cells in the blood-brain barrier. This is called blood-brain barrier disruption. Anticancer drugs infused into the bloodstream may then reach the brain.

High-dose chemotherapy with stem cell transplant is a method of giving high doses of chemotherapy and replacing blood -forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.

Steroid therapy

Steroids are hormones made naturally in the body. They can also be made in a laboratory and used as drugs. Glucocorticoids are steroid drugs that have an anticancer effect in lymphomas.

Treatment of people with AIDS

The treatment of people with AIDS (who have weakened immune systems) use the following procedures:

• steroids with or without radiation therapy
• radiation therapy alone
• chemotherapy followed by radiation therapy

Treatment of primary CNS lymphoma is different in patients with AIDS because the treatment side effects may be more severe.

Treatment of recurrent primary CNS lymphoma

Recurrent primary CNS lymphoma is cancer that has recurred (come back) after it has been treated. Primary CNS lymphoma commonly recurs in the brain or the eye. Treatment of recurrent primary CNS lymphoma may include the following:

• chemotherapy or radiation therapy (if not received in earlier treatment)
• clinical trial of a new drug or treatment schedule

Risk Factors

Primary CNS lymphoma most often occurs in people with AIDS or other people who have weakened immune systems. It also occurs in people who have had a kidney transplant.

External Links

Links from the U.S. National Cancer Institute;

NCI's Live Help online chat service