Medulloblastoma is a tumor that grows in a part of the brain called the cerebellum. The cerebellum is located at the base of the skull, above the brainstem. It is the part of the brain that controls balance, coordination, and other motor functions.
Medulloblastoma is the most common cancerous brain tumor in children. It makes up 20 percent of all pediatric brain tumors. There are between 250 to 500 cases of medulloblastoma found each year in the United States. The tumor is mostly found in children between the ages of 5 and 16, but can occur in older teenagers and even in adults.
Although considered high grade, many children can be cured of medulloblastoma with the right treatment. Doctors previously classified medulloblastoma as standard or high-risk. This was based on factors such as amount of tumor that could be removed surgically, how the tumor appears under the microscope, and how much tumor has spread.
However, in recent years, it was discovered that there are actually four different subtypes of medulloblastoma, based on genetic changes within the tumor These are known as Sonic Hedgehog (SHH), WNT, Group 3 and Group 4..
Doctors don’t know what causes most cases of medulloblastoma. There is some evidence that certain rare genetic conditions may increase the risk of developing medulloblastoma, but in general doctors have found no specific cause for the disease.
Signs and Symptoms
The most common symptoms of medulloblastoma are headaches and vomiting, or problems with balance and walking.
Steps in diagnosing medulloblastoma tumors may include taking detailed pictures of the brain and spine with a CT and MRI scan. This is because the tumor can sometimes grow into the spine as well. When the scans confirm a tumor is present, doctors will remove as much of the tumor as possible with surgery. In most cases a lumbar puncture (a needle is inserted into the spine to draw fluid for testing) is also done to look for tumor cells in the spinal fluid. A pathologist - a specialist who examines the tumor tissue under the microscope - then determines the tumor’s type and level of risk.
Treatment for medulloblastoma is based on the following:
- A child’s age
The type of tumor
Whether the tumor has spread
What doctors can tell about how the tumor will behave
Now that we know there are four distinct subtypes of medulloblastoma, doctors believe this will lead to treatments that can be designed for each type of tumor, with fewer side effects, and better chances of cure.
Currently, the first step in treatment is to surgically remove as much of the tumor as possible, followed by chemotherapy.
For the older child, radiation to the brain and spine often follows surgical resection. When patients are younger, doctors try to avoid radiation because it can affect a child’s long-term development. Younger children will begin chemotherapy after surgery, and may receive radiation treatment when they are older.
For children old enough to receive radiation therapy, Cincinnati Children’s is one of only a few pediatric centers in the nation that offers proton beam radiotherapy. This is a highly precise type of radiation that goes to the tumor and spares damage to nearby tissues and organs as much as possible. Chemotherapy follows the radiation treatment.
We also participate in treatment studies that may be helpful; our treatment team will help guide you in deciding what is best for your child.
Our Treatment Team
Whether a child, teenager or young adult, patients who come to us with medulloblastoma have access to a wide-ranging team of cancer care experts. At the core of the treatment team is a neuro-oncologist, a doctor with expertise in treating medulloblastoma. Many of our brain tumor specialists are also researchers, so each patient has access to trials of the most advanced treatments when appropriate.
Our team is always searching for better ways to treat children with medulloblastoma. Many patients can be cured, but cure often depends on the tumor’s type and whether it has spread. Although treatments can be effective, nearly all patients can experience long-term side effects. These may include problems with learning, hearing, hormones, growth and fertility.
For some patients, secondary cancers can develop later in life. We have a range of specialists who can help your child and your family with life during and after treatment. Our specialists include psychologists, social workers, nutritionists and specialists who work to make sure your child does well in school.
Promising Research and Findings
Cincinnati Children’s is one of the nation’s leading pediatric centers for brain tumor treatment and research. Getting scientific discoveries safely and quickly from the laboratory to your child is a major focus of our program.