Oculomotor nerve schwannoma of orbit with extension into cavernous sinus

Schwannomas (neurilemmomas) are benign encapsulated, slow growing peripheral nerve sheath tumors. Primary orbital schwannomas are uncommon, accounting for about 1–4% of orbital tumors. Characteristically, they arise from the first division of the trigeminal nerve. Oculomotor schwannomas are rare tumors with only one case reported till date. Here, we report a 28-year-old male presenting with an axial proptosis of left eyeball with progressive loss of vision. Magnetic resonance imaging of orbit revealed a large left-sided orbital mass extending into cavernous sinus. Surgical excision of the mass was done, and based on clinical, histological, and immunohistochemical analysis, a final diagnosis of oculomotor nerve schwannoma with left orbital extension was made.