Abstract: Objective:To investigate the clinical features of extra-axial medulloblastoma(MB) in the cerebellopontine angle(CPA) area and analyze the imaging features and clinical prognosis, and to provide the reference for its clinical diagnosis and treatment. Methods:The clinical data of two patients diagnosed as extra-axial MB in CPA area were collected;the literature review was performed,and the clinical characteristics,diagnostic and treatment methods were analyzed. Results:Two patients were admitted to the hospital due to headache accompanied by hearing loss.The magnetic resonance imaging (MRI) results indicated a mass in the CPA area.All the two patients were treated with the cerebellopontine angle tumor resection. The operation of the two patients was successful, and the tumor located outside the axis seen in the operation, which was confirmed as MB by postoperative pathology. No recurrence or metastasis of tumor was found 15 months after follow-up. Conclusion:The possibility of MB should be considered before operation for the occupying lesions in the extra-axial CPA area.The active operation can improve the prognosis and prolong the survival of the patients.

Key words: extra-axial, cerebellopontine angle, medulloblastoma, prognosis