A rare type of tumor: orbital schwannoma. Case report and literature review

Abstract

Schwannomas arise in the cells responsible for the mielinating the neurons distal to the Obersteiner-Redlich zone. Most of the intracranian Schwannomas are in the posterior fossa, developed from the VIIIth or Vth nerve stheath. The location on other cranian nerves is quite rare, only 6% of the orbital tumors being Schwannomas. We review the case of a 52 years old male patient, presenting for right eye exophthalmia and visual field deficit, diplopia due to VIth nerve paresis, and stubbing pain in the right eye, the MRI showing a tumor, located in the orbital apex displaced the globe forward and superiorly, and the optic nerve medially and superiorly. A modified lateral orbital approach was preferred. The choice of the orbitotomy allowed us to maintain the integrity of the lateral rim of the orbit without the need of a bony reconstruction at the end of the intervention, as it faced the anterior margin of the temporal muscle, covering it and not the skin over the zigomatic bone. The technical approach for orbital schwanomas should be tailored to reach the lesion through an esthetic incision and orbitotomy, immediately under the resected bone, with no need retracting the ocular globe or the vasculonervous elements in the orbit.

Cystic Schwannoma Arising from Supraorbital Nerve Masquerading as a Dermoid: An Unusual Case

“…Schwannomas are benign tumors of peripheral nerve sheath which account for around 1 -6% of all orbital tumors. These tumors are localised, well encapsulated and mostly unilateral which are composed of proliferating Schwann cells [1]. They are mostly unilateral which may arise from supraorbital, infraorbital, supratrochlear, ciliary, oculomotor, trochlear or abducens nerves.…”