Ectopic cerebellum in the posterior cranial fossa.

Isolated, well-differentiated ectopic cerebellar tissue is extremely rare, with only eight cases in the literature. We describe a unique case of histopathologically proven ectopic cerebellar tissue presenting as a discrete extra-axial mass in the posterior cranial fossa. We describe the clinical, CT and MRI findings, as well as the surgical and histopathological findings and review the relevant literature.