Definition
The medulloblastoma has been defined by the World Health Organization (WHO) as a “malignant, invasive embryonal tumor of the cerebellum with preferential manifestation in children, predominantly neuronal differentiation, and inherent tendency to metastasize via CSF [cerebrospinal fluid] pathways.”
Several subtypes of medulloblastoma have been recognized including: (1) desmoplastic/nodular type, (2) medulloblastoma with extensive nodularity, (3) large-cell variant, and (4) anaplastic medulloblastoma.