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Medulloblastomas Medulloblastomas
Medulloblastomas are tumors that develop in the brain. These tumors are malignant, or in other words, cancerous. They are much more common... Medulloblastomas

by Kimberly Allen, RN

Medulloblastomas are tumors that develop in the brain.  These tumors are malignant, or in other words, cancerous.  They are much more common in children, by at least ten times, than adults.  In fact medulloblastomas are the most frequently diagnosed malignant brain tumor in children accounting for as much as 20% of all brain tumors diagnosed in children.  Though medulloblastoma can develop at any age it most frequently develops in children between 3 to 8 years of age and is more common in boys than girls.  In the US there are at least 500 new cases of pediatric medulloblastoma diagnosed every year.
Medulloblastomas usually develop in the cerebellum, which is the area to the back of the brain that controls your balance and coordination as well as several cognitive functions.  However, it can also develop in the posterior fosa which covers the cerebellum as well as the medulla and pon’s.  Medulloblastoma is referred to as a PNET tumor (infratentorial primitive neuroectodermal) and it is the most common of the PNET tumors of the brain.  These types of tumors are considered extremely aggressive.  They have the ability to use the cerebral spinal fluid to spread rapidly throughout the central nervous system, a feature other types of brain tumors lack.brain tumor2
The cause of medulloblastoma, like most brain tumors, remains unknown though researchers continue to look for possible causes and even possible risk factors.  However, some believe that it may develop from cerebellar stem cells that were unable to divide and individualize into their appropriate cell type.  There have also been some genetic studies done.  These studies have shown that there are four specific molecular and clinical varieties of certain genes that compose medulloblastomas.  These varieties were further sub grouped into group 3 and group 4 with one group having a better prognosis than the other.
The symptoms pf medulloblastoma result from the increased intercranial pressure caused by the tumor.  The first symptom of increased intercranial pressure is usually headaches along with nausea and vomiting usually occurring in the morning then progresses over time.  Frequently in these early stages children are frequently misdiagnosed with migraines and/or a gastrointestinal condition.  Then as the tumor grows, because medulloblastomas are located in the part of the brain responsible for movement your child may demonstrate poor balance and clumsiness.  They may also have difficulty with hand writing and other fine motor skills that worsen over time.  Some children also experience eye and vision problems.
Unfortunately it is usually 1 to 5 months after the symptoms manifest before a diagnosis is made.  Once diagnosis is made it’s important to find a Dr that specializes in pediatric brain tumors immediately.  The first step in treating is always surgical removal of as much of the tumor as possible.  Surgery is then followed by chemotherapy and/or radiation therapy.  Experts have found that by combining the therapies the 5year survival rates for children suffering from medulloblastoma is as high as 80%.  However, the survival rate for children under 3 years of age is not as high.
There are many things that can affect the outcome of your child’s treatment including the overall health of your child.  Children that eat healthy diets, exercise regularly and maintain a normal body weight as well as have no other health issues tend to do better than children that are over weight or obese.  The other major factors are the size, type, and location of the tumor as well as how far it has spread.  Your child’s pediatric oncologist will run numerous tests to determine the condition of the tumor as well as establish a multidisciplinary team of Drs that specialize in treating brain tumors including a neurosurgeon, neurologist, and an oncologist as well as nurses that specialize in oncology.  There may also be other health professionals on the team like a dietician and social worker.  Having your child diagnosed with any type of cancer is devastating and extremely stressful for the child and family/  It’s very important to have a support system that you can depend on to help you cope with the stressors that accompany this type of medical event.  The more support you have the better you can cope with the everyday stressors like running to appointments, not forgetting the other kids or even to pick up that gallon of milk at the store.  The less your stress is projected outwardly for your child to see which decreases their stress and improves their chances of survival.

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