Contralateral metastatic cerebellopontine angle glioblastoma: A rare manifestation.

Background: Glioblastoma is the most common glioma presenting within adults with an incidence of 10 per 100,000 people globally. These are mostly supratentorial tumors with rare cases of extra-axial spread. Even rarer is the presentation of glioblastoma within the cerebellopontine angle (CPA). Here, we present a case of a previously resected and irradiated glioblastoma metastasizing from the right temporal lobe region to the contralateral CPA.

Case Description: A 24-year-old female who previously underwent surgery and concurrent chemoradiotherapy for a right temporal glioblastoma in August 2020, presented to us 6 months later with headaches, vomiting, and dizziness for the past 6 days. She had left-sided dysmetria on examination. MRI of the brain showed an extra-axial, heterogeneously enhancing lesion within the left CPA. The patient subsequently underwent a left retrosigmoid craniotomy and maximum safe resection of the lesion. Histopathology reported the lesion as a glioblastoma.

Conclusion: Glioblastoma within the CPA is rarely reported within the literature. To date, our case is the first instance of an extra-axial contralateral metastasis of glioblastoma.