DefinitionPosterior fossa tumor is a type of brain tumor located in or near the bottom of the skull.Alternative NamesInfratentorial brain tumors; Brainstem gliomaCauses, incidence, and risk factorsThe posterior fossa is a small space in the skull, found near the brain stem and cerebellum. The cerebellum is the part of the brain responsible for movement, balance, and coordination.If a tumor grows in the area of the posterior fossa, it can block the flow of spinal fluid and cause increased pressure on the brain and spinal cord.Most tumors of the posterior fossa are primary brain cancers, which start in the brain, rather than spreading from elsewhere in the body.There are no known cause or risk factors associated with a posterior fossa tumor.SymptomsSymptoms occur very early with posterior fo