Optic nerve glioma: A great mimicker.

Area of Science:

• Neuro-oncology
• Ophthalmology
• Pathology

Background:

• Optic gliomas can exhibit arachnoid proliferation, though it is uncommon.
• Chondroid and chordoid metaplasia have not been previously documented in optic gliomas.

Observation:

• A 27-year-old male presented with vision loss, vomiting, and headache.
• CT revealed a contrast-enhancing mass from the planum sphenoidale, involving the optic nerve.
• Initial impression was optic nerve sheath meningioma.

Findings:

• Histopathology revealed a glial tumor with significant fibroblastic and arachnoid cell proliferation.
• The tumor showed chondroid and chordoid differentiation with myxoid change and collagenization.
• Immunohistochemistry (GFAP, EMA, S-100) and reticulin stain confirmed optic glioma with metaplasia.

Implications:

• This case presents a diagnostic challenge due to features mimicking chondrosarcoma or chordoid meningioma.
• Clinical correlation and specific stains like GFAP are crucial for differentiating these conditions.
• Understanding these rare metaplastic changes is vital for accurate optic glioma diagnosis and management.