Medulloblastoma is the most common type of malignant brain tumor in childhood. It is an aggressive solid tumor malignancy that develops in the posterior fossa, which contains the brain stem and cerebellum. Boys are affected more frequently than girls, with cases usually occurring between 5 and 9 years of age.

Signs and symptoms are related to cerebellar dysfunction and increased intracranial pressure due to blockage of the fourth ventricle. Patients commonly present with headache, nausea, vomiting, imbalance, and visual disturbances. Nerve compression may cause truncal ataxia, seizures and sensory deficits.

The imaging modality of choice is MRI with gadolinium contrast. Treatment usually consists of surgery, radiation, and chemotherapy.