Medulloepithelioma is a rare type of brain tumor. It is a complex medical term that describes a tumor that originates from embryonic tissue in the central nervous system. A medulloepithelioma is usually found in the cerebellum, the part of the brain that controls movement and coordination. Brain tumors are usually diagnosed through a biopsy, magnetic resonance imaging (MRI) or computed tomography (CT) scans. Medulloblastoma is another word that is often used to describe this type of brain tumor. Other synonyms for medulloepithelioma include primitive neuroectodermal tumor, PNET, and CNS embryonal tumor. It is important to monitor and treat medulloepithelioma as early as possible to increase the likelihood of successful treatment.