Background: Oculomotor nerve schwannomas are extremely rare tumors. There are only 40 cases reported in the literature. There is no standard treatment for these rare tumors.

Case Report: The authors have reported a case of a 41-year-old Thai man presenting with progressive visual loss of the left eye for 6 months without diplopia. Visual acuity was 20/70 in the right and 20/400 in the left. There was no limitation of eye movement. MRI showed a 42.5 ml mass in the suprasellar region compatible with a schwannoma. The patient underwent a left pterional craniotomy with partial tumor removal. The pathological section confirmed a diagnosis of schwannoma and the patient received postoperative stereotactic radiotherapy.

Conclusion: Options for treating these rare tumors include clinical observation, surgical resection or stereotactic radiation. High incidence of complete third nerve palsy following surgery has been reported in the literature. Therefore, a subtotal removal of large oculomotor schwannoma followed by stereotactic radiotherapy could provide a safer alternative compared to radical surgery.

Keywords: Oculomotor nerve, Schwannoma