[Optic nerve schwannoma]

Abstract

Objective: To report the occurrence of an orbital schwannoma probably arising from the optic nerve sheath.

Patient and method: Clinical case report.

Results: A 65-year-old patient presented with a painless, progressive right proptosis over five years. Magnetic resonance imaging revealed an intraconal mass, radiographically consistent with a cavernous hemangioma. Surgical resection was performed and pathology disclosed a schwannoma affecting the optic nerve. The optic nerve, which does not contain Schwann cells, is exceptionally rarely affected by Schwannomas, which may arise from a few sympathetic nerve fibers or from a few ectopic cells, not normally present within the optic nerve.

Conclusion: The radiologic appearance of the very rare optic nerve Schwannoma may be confused with a cavernous hemangioma, a more common tumor in this location.