It originates in the part of the brain that is towards the back and the bottom, on the floor of the skull, in the cerebellum, or posterior fossa.

[3] The brain is divided into two main parts, the larger cerebrum on top and the smaller cerebellum below towards the back.

The child typically becomes listless, with repeated episodes of vomiting, and a morning headache, which may lead to a misdiagnosis of gastrointestinal disease or migraine.

[6] Soon after, the child will develop a stumbling gait, truncal ataxia, frequent falls, diplopia, papilledema, and sixth cranial nerve palsy.

Extraneural metastasis to the rest of the body is rare, and when it occurs, it is in the setting of relapse, more commonly in the era prior to routine chemotherapy.

[13][14][6][16][17][18][19][3][excessive citations] The tumor is distinctive on T1- and T2-weighted MRI with heterogeneous enhancement and a typical location adjacent to and extension into the fourth ventricle.

The tumor is very cellular, with high mitotic activity, little cytoplasm, and a tendency to form clusters and rosettes.

[20] DNA methylation profiling of medulloblastoma allows robust sub-classification and improved outcome prediction using formalin-fixed biopsies.

Prognosis is worse if the child is less than 3 years old, degree of resection is inadequate, or if any CSF, spinal, supratentorial, or systemic spread occurs.

Side effects from radiation treatment can include cognitive impairment, psychiatric illness, bone growth retardation, hearing loss, and endocrine disruption.

An approach to monitor tumor development and treatment response by liquid biopsy is promising, but remains challenging.

[26] A few different chemotherapeutic regimens for medulloblastoma are used; most involve a combination of lomustine, cisplatin, carboplatin, vincristine, or cyclophosphamide.

Patients diagnosed with a medulloblastoma or PNET are 50 times more likely to die than a matched member of the general population.

[41] Using gene transfer of SV40 large T-antigen in neuronal precursor cells of rats, a brain tumor model was established.