Medulloblastoma is a type of brain cancer. It most often grows in children and young adults.
How a medulloblastoma grows
Medulloblastoma is a primary brain tumor. This means it starts in the brain instead of going to the brain from somewhere else in the body. This type of tumor grows fairly fast. It grows in the cerebellum, near the back of the brain. The cerebellum controls balance and coordination. This type of tumor may spread (metastasize) in the brain and spinal cord. A tumor that has spread is harder to treat. Medulloblastoma rarely spreads to other parts of the body. But a tumor in the brain may press against a part of the brain and cause problems.
Types of medulloblastoma
Medulloblastoma has been categorized into different types based on the appearance of the tumor cells under the microscope. But now, doctors have begun to categorize them into 4 subgroups based on the genetic features of the tumor cells. Some subgroups are harder to cure than others. Because of this, eat subgroup may be treated differently.
What causes medulloblastoma?
Researchers are still learning why this kind of brain tumor grows. Certain gene changes may cause the tumor to grow. A small number of people with the tumor have a gene disorder that raises their risk for the tumor. These include Gorlin syndrome and Turcot syndrome. But most people with medulloblastoma do not have a gene disorder.
Symptoms of medulloblastoma
Symptoms may begin slowly and get worse as the tumor grows. Headache is common. A brain tumor may block the normal flow of cerebral spinal fluid (CSF). This leads to increased intracranial pressure (ICP). This may cause headache, nausea, vomiting, and dizziness. Because the tumor grows in the cerebellum, it may affect balance and coordination early on. The symptoms of medulloblastoma may include:
Headache, especially in the morning or middle of the night
Nausea and vomiting, which may be worst in the morning
Changes in ability to think
Balance problems or clumsiness
Double vision or other eye problems
The healthcare provider will ask about your child’s health history and symptoms. The provider may also ask about your family’s health history. Your child will be given a physical exam, including a neurologic exam. He or she may be asked to do simple things like walk, touch finger to nose, hold his or her hands out, or follow a light with his or her eyes. If a healthcare provider suspects a brain tumor, your child may need tests such as:
MRI of the brain and spinal cord
Surgery to remove the tumor and look at the tissue for type and grade of tumor
Spinal tap (lumbar puncture) to look for tumor cells in the cerebrospinal fluid (CSF)
Your child should see a doctor that treats brain tumors. This may be a neurologist, neurosurgeon, or neuro-oncologist. The doctor will explain your child’s test results, including the pathology report. This report tells the size, location, type, grade, and other information about your child’s tumor.
Treatment for medulloblastoma
The healthcare team will decide the best treatment plan for your child. The plan depends on the type of tumor and where it is. Your child's main treatment may be surgery. This is done to remove as much of the cancer as possible. The tumor is removed and looked at to find out the tumor type and grade. After surgery, your child may have radiation therapy. He or she may also have chemotherapy.
If your child has increased intracranial pressure, he or she may need a shunt. This is a tube put in the head to help drain excess CSF. Your child will need to have follow-up MRI scans done to see how well the treatment is working.
Possible complications of treatment
Some possible complications of treatment include:
Temporary brain damage (posterior fossa syndrome) because of surgery that may cause problems with language, emotions, and movement for months or years
Nausea, vomiting, and tiredness (fatigue) from radiation therapy or chemotherapy
Infertility or changes in thinking from radiation therapy
Slowed growth and development
Increased risk of other cancers
Increased risk of stroke later in life
Most children with medulloblastoma have a good outcome. In some cases, the tumor comes back after treatment. To check for this, your child will likely need to have follow-up MRI scans in the weeks after surgery and then a few times a year after that. Your child may also benefit from long-term care from healthcare providers who focus on childhood cancer survivors.
January 09, 2018
Clinical presentation, diagnosis, and risk stratification of medulloblastoma, UpToDate, Pediatric Brain Tumors: Innovative Genomic Information Is Transforming the Diagnostic and Clinical Landscape, JOURNAL OF CLINICAL ONCOLOGY (2015), Treatment and prognosis of medulloblastoma, UpToDate
Alteri, Rick, MD,Levy, Adam S, MD