An 8 year old child presented with signs of increased intracranial tension. Imaging studies showed a growth in the brain. Which is the commonest tumor in a child in the posterior fossa of head?

Medulloblastoma arises in the posterior pa of the cerebellar vermis and neuroepithelial roof of the fouh ventricle in children. It accounts for 20 percent of childhood brain tumors. Primitive neuroectodermal tumor is the most common type of medulloblastoma. Most occur in the first decade of life, but there is a second peak around age 30. Medulloblastoma is the most common malignant pediatric brain tumor. They are usually midline. Most occur in the cerebellum and present with symptoms of increased ICP. Ref: Ropper A.H., Samuels M.A. (2009). Chapter 31. Intracranial Neoplasms and Paraneoplastic Disorders. In A.H. Ropper, M.A. Samuels (Eds), Adams and Victor's Principles of Neurology, 9e.