A brain tumor is a mass of abnormal cells in the brain. Most brain tumors in children are primary. This means that they start in the brain and not another part of the body. A tumor can be benign or malignant. Most benign tumors are made up of slow-growing cells that rarely spread. They are not likely to be cancerous. Most malignant tumors are made up of fast-growing cells that invade surrounding tissue. They are more likely to be cancerous. Both benign and malignant brain tumors can be life threatening. They can require intensive treatment.
There are many types of brain tumors. They can occur in any area of the brain including the lining of the brain or the brain itself. Some of the more common types of brain tumors in children include:
Gliomas. These are tumors that start in the glial cells. The glial cells make up the supportive tissue of the brain.
Astrocytomas are a type of glioma that often form in the cerebellum. The cerebellum lies at the base of the brain and is the part that controls balance and coordination. These tumors can form in other parts of the brain as well.
Brainstem gliomas form in the brainstem, which is located at the base of the brain. The brainstem controls basic functions such as breathing, heart rate, and blood pressure.
Ependymomas are a type of glioma that can form in the hollow spaces in the center of the brain (ventricles). The ventricles make fluid that helps protect the brain and spinal cord.
Optic nerve gliomas form near the optic nerves. The optic nerves carry messages from the eyes to the brain.
Meningiomas. These are tumors that grow in the outer linings (meninges) of the brain and spinal cord. These tumors are usually benign and slow-growing. They are more common in adults than in children.
Primitive neuroectodermal tumor (PNET): These tumors start in brain cells that are still forming. They can occur anywhere in the brain. PNET tumors are usually fast-growing and malignant.
Medulloblastomas are a common type of PNET. They form in the cerebellum.
During a procedure called a biopsy, a small sample of the brain tumor is taken for analysis. It is checked for grade and type. Grade refers to how fast new tumor cells are forming and how quickly they are spreading into surrounding tissue. Grade can range from 1 (lowest) to 4 (highest). This helps the doctor learn more about your child’s brain tumor and how best to treat it. However, not all types of tumors are graded on a scale from 1 to 4, and there are different grading systems. When you discuss the pathology with the surgeon, ask which grading method he or she is using.
This brief glossary includes some of the terms you’re likely to hear when learning about brain tumors. Ask your child’s healthcare provider if you need more information.
Cerebrospinal fluid (CSF): the fluid that forms in the ventricles and that surrounds the brain and spinal cord.
Cranium: the bony structure that protects the brain. The cranium and facial bones form the skull.
Intracranial pressure (ICP): pressure within the skull.
Necrosis: death of tissue.
Pathology: study of changes in the cells and organs of the body that can cause or result in disease.
Resection: surgical removal of tissue.
Stereotactic: method of locating specific sites in the brain using computer software, a head frame, and imaging tests.