[A case of intracranial neurinoma arising from the maxillary branch of the trigeminal nerve].

The intracranial portion of the trigeminal branches is rarely involved in neurinomas. The clinical characteristics including symptoms, neuroradiological findings and results of surgical excision of the previously reported 11 neurinomas and the present case arising from the intracranial trigeminal branches are reviewed. A 59-year-old female patient complained of paresthesia and hypesthesia in the infraorbital region with no other neurological abnormalities. Neuroradiological examinations revealed a round cyst-like tumor located at the middle fossa with enlargement of the foramen rotundum and pterygopalatine fossa. No vascular abnormalities were found by angiography. At surgery, the solid tumor with no cystic component arising from the intracranial maxillary nerve was removed totally via a frontotemporal extradural and interdural approach with zygomatic osteotomy. Histopathology revealed a typical neurinoma. The paresthesia disappeared following surgery. Clinical features of neurinomas arising from the trigeminal branches are varied but distinct depending upon the site of origin of the tumors. These tumors can be removed totally in most cases through the extradural and interdural approach without critical morbidity. Special care should be taken not to cause injuries to the surrounding neurovascular structures such as cranial nerves and internal carotid artery. A small amount of residue is acceptable in cases of tumors with tenacious adhesion to these critical structures.