CNS lymphoma is an aggressive type of brain cancer. Primary CNS lymphoma is found only in the brain, spinal cord, leptomeninges , or eye. Secondary CNS lymphoma is the result of a systemic lymphoma spreading to the central nervous system. Lymphoma results from malignant changes in lymphocyte cells (which are part of the immune system).
Primary CNS lymphoma is a rare disease, more often involving the elderly and immune-comprised. It is a diffuse large B-cell lymphoma. It can be successfully treated, but there is a high likelihood of recurrence. A patient’s immune system status (immune-competent or immune-comprised) can make important differences in the presentation and evaluation of primary CNS lymphoma. Groups at highest risk for primary CNS lymphoma are patients who are immune-comprised (due to HIV/AIDS or medications used for organ or bone marrow transplantation) or those who have an autoimmune disorder.
Signs and Symptoms
The development of symptoms in primary CNS lymphoma is often subacute (between rapid onset and chronic). Symptoms can include:
- Headaches (especially when lying down, sleeping, etc.)
- Motor (strength and movement) or sensation problems
- Difficulties with speech or cognition (thought processes, memory, etc.)
- Cranial nerve difficulties which may involve eye movement, facial function, swallowing, etc. (see Brain Anatomy).
The exact cause of CNS lymphoma, either primary or secondary, is not known at this time.
Diagnosis starts with a history and physical exam, including a thorough neurological examination. Diagnostic pitfalls can result in a delayed or missed diagnosis which then results in a delay in treatment. If your physician suspects a possible primary CNS lymphoma, they will try to withhold corticosteroid therapy if possible until a biopsy is obtained. Corticosteroids can lead to breakdown of the lymphoma cells making stereotactic biopsy and pathologic diagnosis more difficult.
The lesions on brain imaging studies often involve the white matter or corpus callosum (see Brain Anatomy). History of immune-compromise or findings on initial blood testing may raise the suspicion of a primary CNS lymphoma.
Staging essentially determines whether the CNS lymphoma is primary or secondary. This can affect treatment and may have bearing on prognosis (outlook). Although only a small percentage of suspected primary CNS lymphomas are actually secondary (arising from elsewhere in the body), investigation for a systemic lymphoma is often done at the time of initial diagnosis.
Tests and procedures may include: computerized tomography ( CT ) scan of the brain [often the first test obtained], magnetic resonance imaging ( MRI ), positron emission tomography ( PET ) scan, CSF analysis and/or stereotactic biopsy . Blood tests, testicular ultrasound and bone marrow biopsy may also be considered. An ophthalmologic evaluation may be done to look for lymphoma involvement in the eye.
A customized treatment plan is put together for you. Treatment for CNS lymphoma may include one or a combination of the following options:
- High-dose chemotherapy These drugs are cytotoxic (designed to kill cancer cells). Chemotherapy agents may be given into a vein or into the cerebrospinal fluid (CSF).
- Radiation This treatment uses high-energy particles to kill cancer cells by damaging their DNA.
- Targeted therapy These drugs target specific proteins and genes that govern signals for cancer cells to grow, divide, survive and spread. Targeted treatment can also be used to alter an environment that helps a cancer grow.
- Corticosteroids These medications generally are used sparingly in primary CNS lymphoma, even though it may help reduce symptoms. If used prior to a stereotactic biopsy, they may result in no diagnosis or possibly a misdiagnosis since they can directly alter the lymphoma cells. Corticosteroids may also make it more difficult for certain chemotherapy drugs to reach the tumor in the brain. Also, long-term use of corticosteroids can be associated with numerous complications.
- Stem cell transplant (also known as bone marrow transplant) This type of transplant is an infusion of healthy bone marrow to replace diseased bone marrow cells. This type of treatment may be used to treat a systemic lymphoma that has spread to the brain (secondary CNS lymphoma).
Follow-up care includes monitoring for worsening symptoms, effectiveness of treatment and recurrence of the lymphoma. The risk for relapse is thought to decrease with longer disease-free intervals.