Medulloblastoma is most common in children, accounting for 75%-85% of cases and only 15%-25% of cases in adults, accounting for 1% of adult cerebellar tumors. Physical examination may reveal optic papilloedema, difficulty in standing with eyes closed, nystagmus, and spreading nerve palsy. The differences between adult and pediatric cerebellar medulloblastoma are: 1. Adult tumors are mostly located in cerebellar hemispheres, while children are mostly located in cerebellar earthworms. 2. 2. There are more cystic necrosis in adult tumors (80%), while there is almost no cystic necrosis in children. The solid part of adult tumor is mildly to moderately enhanced, while children are obviously enhanced. Most of the medulloblastomas in children have clear borders, while only 11% of them in adults have clear borders. In addition to bone and lymphatic metastases, liver metastases are more common than lung and muscle metastases in children, while lung and muscle metastases are more common than liver metastases in adults. 6. There are more intra-tumor calcifications in adults and less in children.