Medulloblastomas account for 15 to 20 percent of all childhood brain cancers, and about two percent of all primary brain tumours. They develop in the posterior fossa, a region of the brain that controls coordination and balance and contains the cerebellum, brain stem, and fourth ventricle.
The most common symptoms are changes in behaviour, appetite, headaches, nausea, vomiting, drowsiness, and problems with coordination. Unusual eye movements may also occur.
Treatment consists of surgery to remove the tumour, followed by radiotherapy and chemotherapy. Due to its tendency to spread down the spine, radiotherapy is given to the entire brain and spine.