Giant Epidermoid Cyst of the Cerebellopontine Angle: Value of Endoscopic Assistance in Microsurgical Resection.

Background: Epidermoid cysts of the cerebellopontine angle (CPA) are rare benign congenital lesions derived from ectodermal inclusions during early embryogenesis. Despite their slow growth, they may become giant and cause progressive cranial nerve dysfunction due to their close relationship with critical neurovascular structures.

Case presentation: We report the case of a 60-year-old woman who presented with cochleovestibular symptoms, including vertigo, tinnitus, and hearing loss, in association with cerebellar static ataxia. Preoperative examination revealed intact facial and lower cranial nerve function. Magnetic resonance imaging (MRI) revealed a giant CPA epidermoid cyst.

Surgical management: The lesion was resected via a retrosigmoid approach in a semi-sitting position under continuous intraoperative facial nerve monitoring. Microsurgical dissection enabled near-total removal of the tumor while preserving the surrounding neurovascular structures. Endoscopic inspection of the surgical cavity revealed residual tumor remnants in blind spots, which were subsequently removed, ensuring complete resection.

Conclusion: The combination of microsurgical and endoscopic techniques offers a safe and effective approach to the management of giant CPA epidermoid cysts. Complete resection, including capsule removal, remains the key to minimizing recurrence while preserving neurological function.