What is medulloblastoma?
Medulloblastoma is a type of brain cancer. It most often affects children, but it can also happen in adults. This cancer is very rare in people ages 40 and older. These tumors start in the cerebellum, near the back of the brain. The cerebellum controls balance and coordination.
Medulloblastoma is a primary brain tumor. That means it starts in the brain rather than spreading from somewhere else in your body. This type of tumor may spread (metastasize) within your brain and spinal cord. The outlook for tumors that have spread tends to be worse than for tumors that stay in one place.
These are relatively fast-growing tumors. The cancer cells can be one of these types:
- Classic. Small, densely packed, round cells
- Desmoplastic. Mixed dense and loose areas; may have a better prognosis than classic
- Anaplastic. Large, rapidly dividing cells; may have a worse prognosis than classic
Any tumor in your brain may press against a part of your brain and cause problems.
What causes medulloblastoma?
A small number of people with medulloblastoma have certain inherited disorders. These can increase their risk of getting these tumors.
These disorders include:
- Gorlin syndrome, which is linked to several different types of brain cancer
- Turcot syndrome, which is linked to brain cancer and colon cancer
Most people who get medulloblastoma do not get it from an inherited disorder. It is unclear what causes most of these tumors.
There may be certain gene changes that cause the tumors to develop. Researchers have found that many people with this cancer have certain changes in genes that appear linked to these tumors.
What are the risks for medulloblastoma?
Medulloblastoma is more common in children and young adults. In a few people with this condition, there is a link between the tumor and an inherited disorder. In most people, there is no known inherited risk. Researchers are actively trying to understand the genetics of medulloblastoma in hopes of better understanding the risk and possible treatments. The risk for medulloblastoma is higher in:
- People with certain inherited genetic disorders, such as Gorlin or Turcot syndrome
- Young adults
What are the symptoms of medulloblastoma?
Symptoms of medulloblastoma may begin slowly and worsen as the tumor grows. Headaches are common. Sometimes, a brain tumor may block the normal flow of cerebral spinal fluid, leading to increased intracranial pressure. This may cause headache, nausea, vomiting, and dizziness. Because the tumor is usually in the cerebellum, it may affect balance and coordination early on. Some of the general symptoms of medulloblastoma may include:
- Balance problems or clumsiness
- Changes in thinking ability
- Double vision or other eye problems
- Headaches, especially in the morning or middle of the night
- Nausea and vomiting, which may be worst in the morning
How is medulloblastoma diagnosed?
Doctors usually take a complete medical history. They will also ask about your recent symptoms and past medical conditions, including a family medical history. You will need a complete physical exam, including a neurologic exam. Your doctor may ask you to do simple things like walk, touch your finger to your nose, hold your hands out, or follow a light with your eyes. If a doctor suspects a brain tumor, then you will probably need imaging tests of your brain. You may need certain tests, such as:
- MRI scan of your brain and spinal cord
- Surgery to remove the tumor and examine the tissue for type and grade of tumor
- Spinal tap (lumbar puncture) to look for tumor cells
You may first see your primary healthcare provider who may refer you to a doctor that deals with brain disorders. This can include a neurologist, neurosurgeon, neuro-oncologist, or other specialist. Your doctor can help you understand your pathology report. This report tells the size, location, type, grade, and other specific information about your tumor.
How is medulloblastoma treated?
Depending on the type and location of your tumor, your healthcare team will decide the best treatment plan for you. In general, the main treatment in adults is surgical removal of as much of the cancer as possible. This both removes the tumor and provides a tissue sample for testing. Complete removal of the tumor increases the chances of a good outcome. A doctor will examine the sample to find out your tumor type and grade. After surgery, you may also have radiation therapy and, in some cases, chemotherapy as well. Depending on your tumor characteristics, you may have one or more of the following treatments:
- Surgical removal of as much of the tumor as possible (usually the main treatment)
- Radiation therapy directed to the brain and spinal cord, including where the tumor was
- Chemotherapy, in addition to surgery and radiation
You may need to have a tube inserted. In this case, your doctor will use a shunt to drain excess fluid and lower your intracranial pressure. You will likely need to have several follow-up MRI scans done regularly to monitor your condition.
You can work with your medical team to decide on the best treatment plan for you. These team members may include the following:
- Neurologist, a specialist in diagnosing and treating diseases of the central nervous system
- Neuro-oncologist, a specialist in brain and spinal cord cancers
- Neurosurgeon, a surgeon who performs brain or spinal cord surgery
- Nurse practitioner
- Radiation oncologist, a doctor who specializes in treating cancer with radiation
- Social worker
What are the complications of medulloblastoma?
Many people with medulloblastoma have a good outcome. Some people have complications due to the surgery or other treatments. In some cases, the tumor comes back after treatment. To check for recurrence, you will likely need to have follow-up MRI scans in the weeks after surgery and then a few times a year after that. One possible complication is posterior fossa syndrome. This a form of temporary brain damage, due to surgery. Symptoms may include problems with language, emotions, and movement. This may last for weeks or years.
Other complications can include:
- Nausea, vomiting, and fatigue, due to radiation therapy or chemotherapy
- Recurrent tumor
- Side effects of radiation, such as infertility or cognitive changes
Talk with your doctor about the risk of treatment complications, your outlook, and the chances of your tumor returning.
Key points about medulloblastoma
Medulloblastoma is the most common malignant brain tumor in children, but is relatively rare in adults. It starts in the brain. These are relatively fast-growing tumors. Here are some key facts about medulloblastoma:
- These tumors start in the cerebellum, the part of the brain that controls your balance and coordination.
- Brain tumors may press against a part of your brain and cause problems.
- Symptoms often include headache, nausea, and vomiting, especially in the morning.
- The tumor may be visible on an MRI scan.
- You may need surgery to remove as much of the tumor as possible.
- You may need radiation therapy and sometimes chemotherapy after surgery.
- Your medical team will likely continue to monitor you for possible recurrence.
- Outcome depends on the patient’s age, stage of the disease when diagnosed, response to treatment, and occurrence, if any, of treatment complications.
Tips to help you get the most from a visit to your healthcare provider:
- Know the reason for your visit and what you want to happen.
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your healthcare provider tells you.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
- Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
- Ask if your condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if you do not take the medicine or have the test or procedure.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your healthcare provider if you have questions.
March 22, 2017
Treatment and prognosis of medulloblastoma. UpToDate.
Fraser, Marianne, MSN, RN,Shelat, Amit, MD