[[Ewing's Sarcoma peripheral primitive neuroectodermal tumor]]

[[Fourth ventricle ependymoma]]:

Usually arises from the floor of the 4th ventricle
    
Typically squeezes out the foramen of Luschka.

Chen et al. encountered a patient with medulloblastoma in which the neuroimaging findings mimicked those of [[dysplastic cerebellar gangliocytoma]]. In patients with a [[posterior fossa tumor]] suggestive of a dysplastic gangliocytoma on neuroimaging studies, a pathologic confirmation is necessary
((Chen KS, Hung PC, Wang HS, Jung SM, Ng SH. Medulloblastoma or cerebellar
dysplastic gangliocytoma (Lhermitte-Duclos disease)? Pediatr Neurol. 2002
Nov;27(5):404-6. PubMed PMID: 12504212.
)).