Central nervous system tumors involving the brain or spinal cord represent the largest category of solid tumors afflicting children. Roughly four in every 100,000 children in North America will have a brain tumor. They are rarely related to syndromes or inherited mutations, with most brain tumors arising by chance due to errors in cell division that cannot be passed on to future generations.
Most pediatric nervous system tumors arise from support cells within the brain or spinal cord called glial cells, but tumors can form from virtually any cell type or its precursor – including the neurons themselves, the coverings of the brain and spinal cord, the bones of the skull, the cells that secrete spinal fluid, and the cells that regulate hormones throughout the body.
Presentation
Because of the remarkable plasticity of the developing nervous system, children with brain and spinal cord tumors will often present with much more subtle symptoms than adults with similar tumors. Early symptoms of a central nervous system tumor can include nausea, vision loss, rapid head growth, balance difficulties, difficulty learning to walk, or persistent head tilt. When a child’s tumor overwhelms their capacity to compensate for the mass, they will often come to medical attention with more dramatic findings, such as severe headache and vomiting.
Most Common Pediatric Brain Tumors
Glioma Tumors arising from the support cells of the brain—glial cells or astrocytes. This group includes juvenile pilocytic astrocytomas, and they comprise approximately 60% of all pediatric brain tumors. Most will be benign, though malignant variants exist.
How are Glioma Tumors treated?
Surgical resection, if deemed safe, is the mainstay of therapy for gliomas. In the case of juvenile pilocytic astrocytomas and other low-grade gliomas, surgery alone may be sufficient to provide a cure. For patients who cannot be cured with surgery and who have evidence of progressive disease, targeted chemotherapy and/or radiation therapy may be required.
Part of the family of tumors known as primitive neuroectodermal tumors (PNETs), this is the most common malignant tumor in children. They account for approximately 30% of all pediatric brain tumors.
How are Medulloblastoma Tumors treated?
Maximal, safe surgical resection is an essential part of any medulloblastoma treatment plan. Complete cure with surgery alone is generally not possible, though, and chemotherapy and radiation is often required, with the exact regimen dictated by the molecular subtype of the tumor.
Ependymoma line the inner surfaces of the brain and spinal cord, where spinal fluid circulates. These tumors account for approximately 10% of all pediatric brain tumors, and they have a propensity for spreading throughout the head and spine by shedding cells into the spinal fluid.
How are Ependymoma Tumors treated?
Maximal, safe surgical resection is the primary treatment modality for ependymomas. Chemotherapy and radiation therapy are also employed following surgery to eradicate microscopic disease that may be left after all visible tumor has been removed.
Symptoms of Brain and Spinal Cord Tumors
| Tumor Location | Potential Symptoms |
|---|---|
| Cerebrum |
|
| Brainstem or Cerebellum |
|
| Spinal Cord |
|
Diagnosis of Brain and Spinal Cord Tumors
A medical professional will use a variety of clinical, radiographic and laboratory tests to try to establish whether a child truly has a nervous system tumor or not. The most important component of any evaluation, however, is the clinical history and physical exam that your child’s neuro-specialist takes.
Possible Diagnostics
| Modality | Tests | Information Provided |
|---|---|---|
| Radiography |
| Imaging of the head and spine provides important information about the extent of the patient’s disease and what critical structures might be affected by further attempts to diagnose or treat the tumor. In most cases, imaging will include the entire head and spine, as many brain tumors have the potential to spread to the spine. A definitive diagnosis by imaging alone is often not possible, and a tissue sample is almost always required for a definitive diagnosis. |
| Laboratory |
| Can be helpful in the early diagnosis or staging of some pediatric tumors, particularly pituitary or pineal region tumors. In specific cases, bloodwork or spinal fluid tests can establish a diagnosis without the need for a tissue biopsy. |
| Procedures |
| Lumbar puncture and stereotactic biopsy may be part of the workup for some tumors, particularly when it is advantageous to have a definitive diagnosis prior to considering an attempt at surgical resection. Angiograms – a procedure that allows for high-resolution images of a patient’s blood vessels to be taken – can also provide valuable information about tumors with a high propensity for bleeding or located near critical vessels. In certain cases, an angiogram may also allow for vascular tumors to be partially treated prior to attempting a conventional surgical resection. |
| Pathology |
| Ultimately, only a pathologist review of a sample from a tumor can definitively provide a diagnosis. Molecular and genetic testing of the tumor also provides information that can predict how a tumor is likely to behave in the future and which types of therapy will best treat it. |
Treatment of Pediatric Brain and Spinal Cord Tumors
Pediatric brain and spinal cord tumor treatments are devised in a multidisciplinary fashion. Each child’s case is reviewed by neurosurgery, neuro-oncology, neuro-radiology, and radiation oncology. When appropriate, additional specialties such as neurology, ophthalmology, endocrinology or general surgery may need to be involved, such as when a patient’s tumor is suspected to cause dysfunctions particular to other organs systems in the body.
In most cases, the initial step in treating a nervous system tumor will be to attempt surgical removal of the tumor. Our team of pediatric neurosurgery specialists have extensive experience safely removing some the most challenging types of brain and spinal cord tumors in pediatric neuro-oncology. Your surgeon and the neuro-oncology team will guide you, step by step, through your child’s surgical plan and expected post-operative recovery. We use advanced stereotactic, neuro-endoscopic, and minimally invasive techniques, wherever possible, to minimize the potential surgical risks to our patients while accelerating patient recovery.
If chemotherapy or radiation therapy are required, our team of neuro-oncologists and radiation oncologists will tailor the therapeutic regimen your child receives to the particular molecular profile of their tumor. In cases where pediatric nervous system tumors possess exploitable mutations, this approach can produce improved tumor control and limited treatment-related side effects.
Long-Term Treatment of Pediatric Tumors
We strive to ensure that all our pediatric tumor patients live long and active lives. In pursuit of that aim, our tumor care team follows patients out into young adulthood to watch for possible late effects of cancer treatments. Our team of oncologists, physical therapists, audiologists, cardiologists, psychologists and endocrinologists continue to monitor and support our patients throughout their developing years so that we can provide them with the best footing for transitioning to an adulthood beyond their childhood cancer diagnosis.