[Orbital neurinoma presenting orbital apex syndrome]

A 75-year-old man presented a twelve-day history of double vision and retro-ocular pain with rapid deterioration of visual acuity. Neurological examination on admission demonstrated right oculomotor palsy and abducence palsy, visual loss in the right eye, and hypesthesia and pain in the right supraorbital nerve. CT scan and MRI disclosed a mass in the right orbital apex. An emergency operation via a frontotemporal extradural approach was performed to decompress the optic nerve. The anterior clinoid process and minor wing of the sphenoid were drilled to expose the optic canal and superior orbital fissure. When the periorbita just beside the optic sheath was opened, a grayish colored mass was observed beneath the superior rectus muscle. The mass was dissected from the surrounding intraorbital tissue and was removed completely. The postoperative course was uneventful. The patient experienced complete disappearance of the ocular pain and complete restoration of his visual acuity. Orbital neurinoma is a benign tumor accounting for between 2.1 and 6.8% of all orbital tumors in the large series. The salient clinical symptom is exophthalmos followed by mass palpability. However, an orbital neurinoma presenting orbital apex syndrome is quite rare. In the case with orbital apex syndrome, it is sometimes impossible to recover visual acuity even though the optic nerve decompression is promptly performed. In such a case, only an emergency approach to the lesion can rescue the visual acuity.