<prompt> Common posterior cranial fossa tumours include all of following exceptMedulloblastomaOligodendrogliomaEpendymomaCystic astrocytoma  <response>: Oligodendrogliomas are uncommon tumours of childhood, occur predominently in the cerebral cortex and originate in white matter Supratentorial.Common childhood infratentorial post fossa tumorsCerebellar astrocytoma cystic astrocytoma 3 Brainstem glioma2. MedullOblastoma Primitive neuroectodennal tumor 4 Ependymoma 