Extracranial Trigeminal Schwannoma in the Pterygopalatine Fossa Successfully Resected by the Endoscopic Modified Medial Maxillectomy Approach

Tumors in the pterygopalatine fossa (PPF) are rare, and the most commonly encountered ones are benign neurogenic tumors, such as schwannomas. We report a rare case of schwannoma arising from the extracranial trigeminal nerve (the greater palatine nerve) in the left PPF. The endoscopic medial maxillectomy (EMM) has been used as an endoscopic surgical approach for tumors in the maxillary sinus. However, this procedure sacrifices the inferior turbinate and nasolacrimal duct. Recently, an endoscopic modified medial maxillectomy (EMMM) approach was newly developed to preserve the inferior turbinate and nasolacrimal duct. We applied the EMMM approach for resection of the schwannoma in the PPR. Preoperative transcatheter embolization of the left sphenopalatine artery and an intraoperative CT-guided navigation system were useful for safe and complete tumor resection. Besides postoperative hypoesthesia around his left hard palate, the patient developed no other complications. No local recurrence has been observed until now, one-year after the surgery. The EMMM approach using a CT-guided navigation system is useful for surgical resection of benign tumors of the PPF.