When brain cells grow abnormally or out of control, a tumor (a mass of cells) can form. If the tumor puts pressure on certain areas of the brain, it can affect how the body functions.
When discovered early enough, brain tumors are usually treatable. Many that are slow-growing are cured with surgery alone. Other types that are faster-growing might need additional treatment with radiation therapy or chemotherapy, or both.
Types of Brain Tumors
There are many different types of brain tumors. Some are cancerous, and others aren't. Doctors categorize a tumor based on its location, the type of cells involved, and how quickly it grows.
Tumors are grouped into these categories:
Low-grade vs. high-grade: Usually, low-grade tumors are slow-growing, while high-grade tumors are fast-growing and can be cancerous. High-grade tumors can invade nearby tissue or spread to other areas in the body (metastasize), and they are more likely to come back after treatment to remove them. High-grade tumors are generally associated with a poorer outlook.
Localized vs. invasive: A localized tumor is confined to one area and is generally easier to remove, as long as it's in a part of the brain that's easy to get to. An invasive tumor has spread to surrounding areas and is more difficult or impossible to remove completely.
Primary vs. secondary: Primary brain tumors start in the brain. Secondary brain tumors are made up of cells that have metastasized to the brain from somewhere else in the body. In children, most brain tumors are primary.
In children, some of the most common types of primary brain tumors are:
Astrocytomas. These form from star-shaped brain cells called astrocytes. They can be cancerous and low-grade (more common in children) or high-grade (more common in adults).
Ependymomas are cancerous tumors that form from part of the central nervous system called the ependyma. They also can be low-grade or high-grade.
Brainstem gliomas form in the tissue of the brainstem, the part of the brain that connects to the spine. They can be cancerous and are typically high-grade and fast-growing.
Medulloblastomas or primitive neuroectodermal tumors (PNETs) are cancerous, high-grade tumors that start in the posterior fossa, a part of the brain near the base of the skull.
Craniopharyngiomas are non-cancerous tumors that form at the base of the brain near the pituitary gland.
Germ cell tumors usually form in the testes or ovaries but can also form in the brain and central nervous system. They can be cancerous.
Pontine gliomas are cancerous, high-grade tumors that form in a part of the brainstem called the pons.
Optic nerve gliomas form in or around the optic nerve, which connects the eye to the brain. Most optic nerve gliomas are noncancerous and slow-growing.
Doctors don't know what causes brain tumors, but researchers think there may be genetic and environmental causes.
Some kids who have certain genetic conditions have a greater chance of developing brain tumors. Diseases like neurofibromatosis, von Hippel-Lindau disease, and Li-Fraumeni syndrome are all associated with a higher risk of brain tumors.
Signs and Symptoms
A brain tumor can cause symptoms by directly pressing on the surrounding parts of the brain that control certain body functions, or by causing a buildup of spinal fluid and pressure throughout the brain (a condition known as hydrocephalus).
Signs or symptoms vary depending on a child's age and the location of the tumor, but may include:
weakness of the face, trunk, arms, or legs
difficulty standing or walking
in babies, a rapidly enlarging head
Because symptoms might develop gradually and can be like those of other common childhood conditions, brain tumors can be difficult to diagnose. If you ever have concerns about symptoms your child is having, talk with your child's doctor right away.
A doctor who thinks a child might have a brain tumor will do a thorough neurological exam and order imaging studies of the brain: a CT (computed tomography) scan, MRI (magnetic resonance imaging, or possibly both. These let doctors see inside the brain and identify any areas that look abnormal. Although both are painless, they do require children to be still. Some children, especially younger ones, may need to be sedated for these scans.
If imaging studies reveal a brain tumor, then surgery is likely to be the next step. A pediatric neurosurgeon will try to remove the tumor; if complete removal is not possible, then partial removal or a biopsy (removal of a sample for study) may be done to confirm the diagnosis.
The tumor sample is tested and examined under a microscope to learn what type of tumor it is and whether it is low-grade or high-grade. Using this information, doctors can develop the best treatment plan for a child with a brain tumor.
Treatment for a brain tumor requires a team of medical specialists. Most kids with brain tumors need some combination of surgery, radiation therapy, and chemotherapy. Advancements in all three treatment areas in the last few decades have contributed to better outcomes.
Caring for a child with a brain tumor is very complicated and requires close coordination between members of the medical team, which typically will include:
a pediatric neuro-oncologist (a doctor who specializes in treating cancers of the brain or spine)
a pediatric neurologist (a doctor who specializes in disorders of the nervous system)
a pediatric neurosurgeon (a surgeon who operates on the brain or spine)
a pediatric radiation therapist (a specialist who administers radiation therapy)
pediatric rehabilitation medicine specialists, including speech, physical, and occupational therapists
pediatric psychologists and social workers
These experts will choose a child's therapy very carefully. Finding a treatment that will be effective and cure the child but not cause unacceptable side effects is one of the most difficult aspects of treating brain tumors.
Pediatric neurosurgeons are having more success than ever helping cure children with brain tumors. This is partly because of new technologies in the operating room and partly because an aggressive surgical approach at diagnosis can greatly increase the chance for a cure.
Neurosurgeons may use stereotactic devices, which help target tumors by providing 3D images of the brain during surgery. Staged surgeries are also more common. This means that instead of trying to remove a large tumor all at once, surgeons will take out only part of the tumor at diagnosis. The patient will then get chemotherapy and/or radiation therapy to shrink the tumor. The surgeon then operates a second or even a third time to try to remove the rest of the tumor.
After surgery, some patients may not need any more treatment beyond observation (periodic checkups and imaging scans to watch for problems). Many, however, will need radiation therapy, chemotherapy, or a combination of both.
Radiation therapy — the use of high-energy light to kill rapidly multiplying cells — is very effective in the treatment of many pediatric brain tumors. However, because the developing brain in children younger than 10 years old (and especially those younger than 5) is highly sensitive to its effects, radiation therapy can have serious long-term consequences. These may include seizures, stroke, developmental delays, learning problems, growth problems, and hormone problems.
The methods for giving radiation therapy have changed significantly over the last several decades. New computer-assisted technologies allow doctors to construct 3D radiation fields that accurately target tumor tissue while avoiding injury to important brain structures like the hearing centers.
Chemotherapy (chemo) is the use of drugs to kill cancer cells. It is often given through a special long-lasting intravenous (IV) catheter called a central line, and may require frequent hospital stays.
Chemo is routinely used for brain tumors in kids with positive results. Although chemotherapy has many short-term side effects (such as fatigue, nausea, vomiting, and hair loss), it has fewer long-term side effects than radiation therapy. In fact, many children with brain tumors are treated with chemo in order to delay or avoid radiation treatment.
Late effects are problems that patients can develop after cancer treatments have ended. For survivors of pediatric brain tumors, late effects may include cognitive delay (problems with learning and thinking), seizures, growth abnormalities, hormone deficiencies, vision and hearing problems, and the possibility of developing a second cancer, including a second brain tumor.
Because these problems sometimes don't become apparent until years after treatment, careful observation and medical follow-up are needed to watch for them.
In some cases, short-term effects might improve with the help of physical, occupational, or speech therapy and may continue to improve as the brain heals.
In other cases, kids may have side effects that last longer, including learning disabilities; medical problems such as diabetes, delayed growth, or delayed or early puberty; physical disabilities related to movement, speech, or swallowing; and emotional problems linked to the stresses of diagnosis and treatment. Some of these problems may become more severe over time.
Be aware of the potential for physical and psychological late effects, especially when your child returns to school, activities, and friendships. Talk to teachers about how treatment has affected your child and discuss any necessary accommodations, including a limited schedule, additional rest time or bathroom visits, modifications in homework, testing, or recess activities, and medication scheduling. Your doctor can offer advice on how to make this time easier.
Parents often struggle with how much to tell a child who is diagnosed with a brain tumor. Though there's no one-size-fits-all answer for this, experts do agree that it's best to be honest — but to fit the details to your child's degree of understanding and emotional maturity.
Give as much information as your child needs, but not more. And when explaining treatment, try to break it down into steps. Addressing each part as it comes — visiting various doctors, having a special machine take pictures of the brain, needing an operation — can make the big picture less overwhelming. The members of the brain tumor care team are experts at helping families talk with the child and siblings if a family needs help with this.
Kids should be reassured that the brain tumor is not the result of anything they did, and that it's OK to be angry or sad. Really listen to your child's fears, and when you feel alone, seek support. Your hospital's social workers can put you in touch with other families who've been there and may have insights to share.
Also be aware that it's common for siblings to feel neglected, jealous, and angry when a child is seriously ill. Explain as much as they can understand, and enlist family members, teachers, and friends to help keep some sense of normalcy for them.
And finally, as hard as it may be, try to take care of yourself. Parents who get the support they need are better able to support their child.