Schwannoma of the oculomotor nerve.

A 63-year-old woman presented with an extremely rare oculomotor schwannoma not associated with neurofibromatosis, manifesting as a transient diplopia and ptosis. Magnetic resonance images showed a well-enhanced mass extending from the cavernous sinus to the intraorbital region. Surgical exposure confirmed the tumor originating from the oculomotor nerve in the cavernous sinus. The intraorbital cystic part of the tumor was partially resected to preserve the oculomotor function. This is the first case of oculomotor schwannoma in the cavernous sinus with intraorbital component.