A 40-year-old man without stigmata of neurofibromatosis presented with proptosis and impairment of lateral gaze of the left eye. Neuro-imaging studies revealed an extra-axial lytic spheno-orbital mass. The mass was completely removed. Classic schwannoma was documented histopathologically. Schwannosis or hyperplasia of Schwann cells of perivascular nerve plexus may be attributed in the histogenesis of this unusually located schwannoma.
- Intra-osseous schwannoma