[Neurinoma arising from the first branch of the trigeminal nerve: a case report]

A case of a neurinoma arising from the first branch of the trigeminal nerve in a 40-year-old female is reported. The patient was admitted with the chief complaint of loss of Lt. visual acuity and mild hypoesthesia in the area of the first branch of the trigeminal nerve. A CT scan and MRI revealed a tumor extending through the superior orbital fissure into the orbita. Subtotal resection of the tumor was performed by a fronto-orbito-zigomatic approach and a histological diagnosis of neurinoma was made. Although the hypoesthesia remained, the visual acuity was markedly improved postoperatively. A neurinoma arising from the first branch of the trigeminal nerve is very rare. To our knowledge, including our case, only five cases which were described for clinical and diagnostic features and surgical management have been reported. There were three males and two females, and the age ranged from 1 to 57 years. Neurologically, all cases presented hypoesthesia in the area of the first branch of the trigeminal nerve and exophthalmus on admission. Visual disturbance was found in three cases. Radiologically, the enlargement of the superior orbital fissure was revealed in two cases. Angiography performed in three cases demonstrated the avascular mass. Three patients received CT scan and only the present case used MR imaging. Surgical resection was performed in all cases through various approaches. The fronto-orbito-zygomatic approach which was chosen in our case was useful for obtaining a sufficient operative view. As in our case, excellent outcome was achieved in three other cases due to successful tumor resection.