Uncommon presentation: Extra-axial medulloblastoma in the cerebellopontine angle in an adult: Case report and literature overview

Introduction: The medulloblastoma is a pediatric malignant primitive neuroectodermal tumor. It’s occure rarely in adults, accounting for less than 1% of brain tumors. The typical location is the cerebellar vermis toward the fourth ventricle. The extra-axial location of the cerebellopontine angle is extremely rare.
Case report: Reporting a case of extra-axial medulloblastoma at the cerebellopontine angle in a 23-year-old right-handed adult with no significant medical history. The patient presented with gradually worsening headaches, dizziness, and gait disturbances. Clinical examination revealed a conscious patient with a GCS of 15, exhibiting a vestibular cerebellar syndrome, right hemiparesis 4/5, grade II right facial paralysis, right-sided deafness, and bilateral grade I papilledema.
The patient underwent initial surgery, including a primary ventriculoperitoneal shunt to address hypertension syndrome, followed by a retro-mastoid approach to the cerebellopontine angle with macroscopically complete tumor resection. The postoperative course was uneventful, and the histopathological diagnosis confirmed medulloblastoma of the cerebellopontine angle. The patient was subsequently referred for oncology.
Conclusion: The extra-axial medulloblastoma at the cerebellopontine angle is an extremely rare tumor. It should be considered in the differential diagnosis of tumors involving the cerebellopontine angle.