Fully Endoscopic Resection of an Epidermoid Cyst of the Cerebellopontine Angle: Bilateral Resection via a Unilateral Approach

Background and importance: Epidermoid cysts are rare, benign intracranial neoplasms that typically arise at the cerebellopontine angle (CPA) and can be extensive lesions that intricately involve many critical neurovascular structures. We describe the case of a patient who presents with the classic picture of CPA epidermoid cyst and describe the value of the 4K endoscope for resection, which is illustrated in our accompanying surgical video.

Clinical presentation: The patient presents with headache, nausea, and vomiting accompanied by dizziness and balance issues. Radiographic imaging demonstrated a large lesion highly consistent with epidermoid cyst which involved the left CPA, encircled the basilar artery, and extended to the opposite side. Surgery was planned with a small left-sided retrosigmoid craniotomy with use of a 2-dimensional 4K endoscope to aid in resection, particularly of the contralateral side. This approach was successful with gross total resection apparent at 14-mo follow-up.

Conclusion: We describe the use of a fully endoscopic technique from a unilateral approach for resection of a lesion that extended in the CPA bilaterally. Additionally, we highlight the relevant neuroanatomical and neurovascular structures in this highly critical intracranial region which is well-visualized through endoscopy in the associated surgical video.

Keywords: 4K endoscopy; Cerebellopontine angle; Epidermoid cyst; Retrosigmoid approach.