Childhood Optic Nerve Glioma: Vision Loss Due to Biopsy.

Two children without neurofibromatosis type 1 presented with unilateral decreased vision and MRI revealing optic nerve tumors. In the first case, chemotherapy was initiated empirically for presumed optic pathway glioma, but the lesion increased in size with associated clinical worsening, raising concern for a possible alternate diagnosis. Biopsy of the involved optic nerve resulted in worsening of vision due to a branch retinal artery occlusion and showed a grade I pilocytic astrocytoma. In the second case, sudden symptom onset and rapid tumor growth prompted an optic nerve biopsy, resulting in vision loss due to a central retinal artery occlusion and revealing grade I pilocytic astrocytoma. In both cases, tissue diagnosis did not alter the course of management. Instead, biopsy was associated with additional vision loss, highlighting the risk of biopsy in children with isolated optic nerve tumors and imaging that is most consistent with an optic pathway glioma.