Surgical management of giant trigeminal schwannomas extending into the parapharyngeal space

Trigeminal schwannomas extending into the deep parapharyngeal space are relatively rare, and a surgical approach to such tumors has not been well established. We report four cases in which the tumors were completely removed by using a combination of three approaches. Four patients with trigeminal schwannomas extending into the extracranial space were surgically treated using a combination of the transcervical approach, anterolateral retromaxillar pathway via gingivobuccal sulcus, and epi and interdural middle fossa approach. The maximum diameters of the tumors ranged from 4 to 7 cm. Three tumors extended beyond the lower end of the maxillary sinus. All tumors were completely excised. The Karnofsky performance scales after surgery were more than 90% in all patients. Although the tumors extending to the deep parapharyngeal space are difficult to completely remove via a single approach, a combined approach is useful in these huge extracranial extensions.