Medulloblastoma is the most important intracranial cancer in childhood. It typically is located centrally in the cerebellar vermis and infiltrates the brain stem. Notice that in this particular case, acute intratumoral hemorrhage has taken place. It is a type of primitive neuroectodermal tumor of childhood (PNET) and the natural history is highly malignant. However, with combined surgery, radiotherapy and chemotherapy, the five-year survival is about 75% nowadays.