About This Cancer
Brain and spinal cord tumors are the most common pediatric solid tumors. A solid tumor is one that does not originate in the blood or bone marrow. The study and treatment of brain and spinal tumors is often referred to as neuro-oncology, "neuro" referring to the brain, and "oncology" referring to cancer.
When a child is diagnosed with a brain or spinal cord tumor, a multidisciplinary team of Johns Hopkins specialists, including neuro-oncologists, neurosurgeons, neuropathologists, and neuroradiologists work together to determine the optimal treatment. Many factors influence the decision, especially the classification, grading, and staging of pediatric brain tumors. (See additional information about classifiation, grading, and staging under the "Treatment" section below.)
The exact causes of pediatric brain and spinal cord tumors are largely unknown. Tumors can appear at any age. A small number of tumors occur in children with genetic risk factors. Regular "well visits" for infants and toddlers, and periodic check-ups for school age children are key for the pediatrician to recognize changes and/or problems that could indicate a brain or spinal cord tumor.
The symptoms of brain and spinal tumors can often be vague and similar to other less serious conditions. These symptoms include headache, vomiting, and irritability. Some children may experience problems with vision, speech, alertness and concentration, clumsiness, changes in coordination or trouble walking, and, occasionally, seizures. Of course, very young children and infants are unable to complain in words, and certain symptoms may be difficult to recognize. Parents and caregivers should be aware of any fontanelles (depressions in the head), or change in head size. These things are regularly monitored in pediatric "well-child" screenings. Regular care by a pediatrician is a crucial way of identifying potential problems, including cancers, in infants and children.
In order to diagnose a brain or spinal cord tumor, images of the child’s brain and/or spinal cord will be taken. A variety of diagnostic tests may be ordered, including an MRI (magnetic resonance imaging) scan, which creates pictures of body structures and organs. An MRI of the head is a noninvasive procedure that uses powerful magnets and radio waves to construct clear, detailed pictures of brain tissues.
The doctor may also request other images of the brain, such as a CT (computerized tomography) scan, and/or X-rays, and blood tests. These tests also help the doctor determine if the tumor has spread to any other areas of the body. Sometimes, the doctor may request an electroencephalogram (EEG), a test to detect abnormalities in the electrical activity of the brain.
With the exception of only a few tumor types and locations, most brain and spinal cord tumors are initially treated with surgery. Surgery can reduce the size of the tumor, or in some cases, completely remove it. During surgery, tissue will be removed and given to a specialist known as a pathologist. The pathologist will look at the tissue sample under a microscope to determine the exact type of brain or spinal tumor (tumor classification) and the degree of malignancy (tumor grading).
Before treatment begins, the child is evaluated to determine both the size and extent of the tumor, including evidence of tumor spread to other parts of the nervous system or to other parts of the body (tumor staging).
Tumor Classification and Grading
Tumor classification is done during the pathologist's microscopic examination. Brain tumors typically arise from different normal cells of the brain and spinal cord, and the resulting tumors are classified and named based on the type of cells from which they originate.
A majority of tumors arise from cells known as glia and include the ependymal cells, astrocytes, and oligodendrocytes. The respective tumors are known as ependymomas, astrocytomas, and oligodendrogliomas. The suffix "oma" means mass or tumor.
For glial tumors, these tumor classifications may be made even more specific. For example, an astrocytoma refers to a variety of different tumors with varying degrees of aggressiveness. A common type of astrocytoma in children is pilocytic astrocytoma, known for its slow rate of growth and, in many cases, surgical cure. Other forms of astrocytomas include fibrillary types that tend to spread into surrounding tissues and can be more difficult to manage.
Another common class of brain tumors in children is the embryonal or primitive neuroectodermal (PNET) group. Of this class, the cerebellar medulloblastoma (MDL) is the most common.
After the tumor is classified, the pathologist must then estimate the degree of malignancy, or how aggressive the tumor appears. This is called tumor grading. The pathologist looks at a variety of features, including the number of tumor cells that are dividing and growing (known as mitoses). Based on this and other features, the tumor is assigned a number. Aggressive tumors are given a higher number, indicating a higher grade, and less aggressive tumors given a lower number, indicating a lower grade tumor.
In some cases, the grade is implicit in the name. For example, pilocytic astrocytomas are Grade I. Tumors that are more likely to grow and spread, fibrillary lesions, fall along a spectrum of Grade II, III, and IV. Grade II refers to the fibrillary astrocytoma, whereas Grade III anaplastic astrocytoma is intermediate, and the astrocytoma Grade IV tumors are the most malignant form of glia-originating tumors. On the other hand, some tumor types, including medulloblastoma (MDL), are always considered high grade but do not carry a specific numerical designation.
Tumor staging, or determining the extent of tumor spread, may occur before or after surgery. Imaging tests, called scans, will be done before surgery to determine where the tumor is located, if there is more than one tumor, and if it can be removed surgically.
At surgery, the neurosurgeon, an expert in diseases of the brain and nervous system, is able to look directly at the tumor and surrounding tissue in the child’s body, provides additional information to the treatment team, such as how much of the tumor was removed during surgery. Some tumors are more likely to spread than others, and require a careful evaluation to project where the tumors might spread.
In general, glial tumors usually remain in the central nervous system (brain and spinal cord), and do not spread to other parts of the body. For tumors of glial origin, tumor staging may only involve determining if there is evidence of spread to the spinal cord. This is generally accomplished by obtaining an MRI (magnetic resonance imaging) scan of the spine.
For other tumors, the evaluation of possible spinal spread also includes a lumbar puncture (spinal tap). A small amount of fluid is removed and analyzed for the presence of tumor cells. Certain brain tumors, such as medulloblastoma (MDL), can spread to the spinal cord and, though rare, beyond the central nervous system.
If there is evidence that the tumor has spread, additional studies may be ordered. AA member of the treatment team will explain the exact studies required for staging. Some studies, such as the MRI (magnetic resonance imaging) scan of the spine, may be delayed following surgery to be certain that abnormalities noted on the scan do not represent effects of surgery, such as blood from the time of the operation.
It is only following tumor classification, grading, and staging, that the clinician can provide a complete picture concerning prognosis and treatment options. In addition to surgery, the treatment plan may include radiation therapy (targeted X-rays that can destroy tumor cells), and/or chemotherapy (treatment with anticancer drugs).
Common Tumor Types at a Glance
- Most common malignant pediatric brain tumor
- Signs may include headache, vomiting, unsteady gait, and extreme fatigue.
- Can spread (metastasize) along the spinal cord
Surgical removal alone does not cure medullablastoma (MDL). Chemotherapy (treatment with anticancer drugs) and radiation therapy (targeted X-rays that can destroy tumor cells), are always used following surgery.
This type of tumor is more difficult to manage in children younger than age three.
- Accounts for 10 to 30 percent of pediatric brain tumors; most common in children 5 to 8 years old
- Usually benign, cystic, and slow-growing
- Signs usually include clumsiness of one hand, gait changes (stumbling to one side), headache and vomiting
The cornerstone of treatment is surgical removal of the tumor. If complete removal is not possible, radiation therapy (targeted X-rays that can destroy tumor cells), and/or chemotherapy (treatment with anticancer drugs) may be beneficial.
Brainstem glioma (instrinsic pontine glioma):
- Tumors of the pons (mass of nerve tissue at the base of the brain that connects the different lobes of the brain)
- Occurs almost exclusively in children
- Accounts for 10 to 15 percent of primary brain tumors in children; the average age is 6 years
- May grow to very large size before symptoms are present
- Signs include double vision, facial weakness, difficulty walking, and vomiting
- Surgical removal is impossible due to the location of the tumor
Radiation therapy (targeted X-rays that can destroy tumor cells), and experimental chemotherapy (treatment with anticancer drugs) may be used to slow tumor progression.
- Accounts for 8 to 10 percent of pediatric brain tumors; the third most common pediatric brain tumor
- Tumor growth rates vary
- Tumors are located in the ventricles of the brain and often obstruct the flow of cerebrospinal fluid (CSF)
- Signs include headache, vomiting, and loss of muscle control
Therapy may include surgery, radiation therapy (targeted X-rays that can destroy tumor cells), and, less often, chemotherapy (treatment with anticancer drugs).
Pediatric oncology has a program devoted solely to the research and management of pediatric brain and spinal cord tumors. We offer a unique collaborative approach to treatment, in which these tumors are managed from the onset by a team of experts, ensuring comprehensive care across all disciplines, including oncology, neurosurgery, neurology, neuro-ophthalmology, radiation oncology, neuropathology, and neuropsychology, among others.
New drugs, and old drugs used in new ways, are offering promise in the treatment of childhood brain and spinal tumors. Our experts are at the forefront of these new discoveries, designing new clinical trials and collaborating with other cancer centers in cooperative group studies.
Brain and spinal tumors are treated in our Divisions of Oncology, Neurology and Neurosurgery.