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Medulloblastoma Medulloblastoma
Medulloblastoma is a type of brain tumor that begins in the cerebellum. It is the most common type of tumor belonging to a... Medulloblastoma

by Kimberly Allen R.N.

Medulloblastoma is a type of brain tumor that begins in the cerebellum.  It is the most common type of tumor belonging to a group of tumors known as primitive neuroectodermal tumors or PNET’s.  Medulloblastoma is the most commonly diagnosed malignant brain tumor.  Medulloblastomas are most diagnosed in children and teens.  It can develop in adults but it is very rare. At least 40% of all medulloblastomas are diagnosed in children under the age of 5 with children between the ages of 5 and 9 close behind at 31%.  The numbers decrease significantly after the child reaches 10 years of age and even further after 15 years of age.  There are 500 new cases of medulloblastoma diagnosed in the US every year.  Medulloblastomas are also much more common in males than females.
In children medulloblastomas are classified as either average risk tumors depending on how much of the tumor the Dr was able to remove during surgery and  whether or not it has spread.  An average risk tumor can be nearly completely removed during surgery.  The tumor is contained in the back of the brain and has not spread.  A high risk tumor is one that can not be completely or nearly removed and/or that it has spread to other areas in the brain or the spine or spinal fluid.  On rare occasions they can re appear somewhere else in the body.  Unfortunately in the majority of cases the cause of medulloblastoma is unknown, however there is research to indicate it is associated with certain disease like Li fraumeni syndrome, Gorlin syndrome, and turcot syndrome.
Children that have a medulloblastoma usually complain of symptoms that are similar to hydrocephalus, mostly because the medulloblastoma causes intercranial pressure.  The symptoms of medulloblastoma also vary depending  on the childs age.  Children that are too young to communicate will demonstrate behavior changes and those that are older like preschoolers will be irritable and listless and will have vomiting.  they also will not be as playful or want to interact with others.  Adults and older children with medulloblastoma will complain of headaches especially when they get up in the morning.  The vomiting is also more common in the morning and is not accompanied by nausea.  Many children also develop vision problems as well as difficulty with balance.
The tests that your Dr will need to do to diagnose medulloblastoma  mostly involve imaging, including CT scans and MRI’s.  Patients that are displaying mild symptoms with minimal hydrocephalus can get all their tests done as an outpatient, however  those that have advanced symptoms and a significant amount of hydrocephalus need to be hospitalized immediately and monitored closely  during testing.  Surgery to remove as much of the tumor as possible is the main treatment.  After the surgery treatment depends of the staging of the tumor.  A follow up MRI is done with in 48 hours after surgery to determine how much of the tumor remains and if it has spread.  Following surgery the Dr may also recommend  radiation and/or chemotherapy.  Research indicates that irradiation of both the brain and spinal column significantly improves the survival rates.  Unfortunately radiation treatment can also cause damage to a developing nervous system causing other complications like lowering intelligence levels, dysfunction of the endocrine system and alter behavior.  Children that receive radiation treatment also tend to be smaller in stature.  The use of chemotherapy has also evolved over the years and many of the newer medications used in chemotherapy have fewer side effects than in the past while also offering a better survival rate.  Many pediatric oncologists prefer to use certain chemotherapy regimes in order to either decrease the dose of radiation or delay radiation treatment until the child can tolerate it with fewer side effects.  Because a diagnosis of medulloblastoma is so traumatic for the entire family not just the patient most  facilities focus on family oriented care that not only provides physical and emotional support but also are willing to work with you in developing a plan of care that is the most effective in treating your child.
The most important thing to remember is that there is no cause for these types of cancers.  There is nothing that you did to cause it nor is there anything you could have done to prevent it.

Kimberly Allen is a registered nurse with an AND in nursing. She has worked in ACF, LCF and psychiatric facilities, although she spent most of her career as a home health expert. She is now a regular contributor to, dispensing advice and knowledge about medical issues and questions. You can reach her with any comments or questions at