Endoscopic Transnasal Excision of Foramen Ovale Schwannoma: A Case Report and Literature Review

Background: Schwannomas are benign, slow-growing tumors that develop from Schwann cells in the nerve sheath and can occur in peripheral, cranial, or autonomic nerves. Foramen ovale schwannomas are a rare variant in the head and neck region representing 1%-2% of all intracranial schwannomas, with parapharyngeal space involvement complicating surgical resection. Case Presentation: A 48-year-old male presented with headaches after an episode of light-headedness along with facial pain. MRI showed a well-defined lesion measuring 50 × 40 × 20 mm in the left masticator space, extending superiorly up to the left temporal lobe. CT imaging revealed a 28 × 25 × 31-mm lesion in the left masticator space, extending through the foramen ovale into the medial left temporal lobe. The tumor was classified as Type ME under the Yoshida and Kawase system, involving both the middle cranial fossa and extracranial extension. Management: A minimally invasive endoscopic transnasal approach was used for tumor resection, prioritizing preservation of the internal maxillary and carotid arteries. This approach was selected for its reduced morbidity and quicker postoperative recovery, as the tumor's medial location made it amenable to endoscopic access. The patient had an uneventful recovery. No new neurological deficits were reported at follow-up, and facial pain improved significantly. Conclusion: This report reviews the current literature on the diagnosis and management of trigeminal schwannoma, highlighting minimally invasive techniques as effective alternatives to traditional surgical approaches.