Who Deserves a Second Chance?

An 81-year-old woman presented with visual loss OS, down to light perception, associated with pain on left gaze and scalp tenderness. Funduscopic exam showed pallid disc edema in the left eye. Initial concern was for GCA. ESR normal for age, CRP mildly elevated, but TA biopsy was negative for evidence of arteritis. Vision progressed to no light perception. MRI revealed enlargement and enhancement of the left optic nerve. CT chest, lumbar puncture with CSF analysis including cytology were unrevealing. Re-examination reveals vitreous cells in left eye. A vitreous biopsy evaluating for an infiltrative process was negative for monoclonal lymphoid population. Ultimately the patient was sent for an optic nerve biopsy which revealed a diffuse astrocytoma, WHO Grade II. Gliomas of the optic nerve are rare, and account for 1.5-3.5% of all orbital tumors. While more cases are seen in children, those found in adults are overwhelmingly classified as grade I or IV (1, 2). The literature only reports two cases of histologically proven WHO Grade II optic nerve gliomas (3,4). Pathology in our case was positive for IDH1 (R132H mutant) and p53 immunohistochemistry markers, which further supports the histological diagnosis of WHO grade II astrocytoma. 80% of WHO grade II tumors show IDH mutations and <1% of WHO grade I tumors are positive for p53 mutations. To our knowledge, this is the third reported case of optic nerve histologically proven WHO grade II optic nerve glioma.