Pure Intra-optic Canal Schwannoma: Report of Two Cases.

We report two cases of "pure intra-optic-canal schwannoma." The first patient was a 67-year-old female who presented with a visual field defect and visual impairment in the right eye, and the second patient was a 17-year-old female with progressive visual impairment. Both patients underwent tumor resection through frontotemporal craniotomy combined with extradural anterior clinoidectomy and unroofing of the optic canal. The tumors were not attached to the optic nerve (ON) and were located exclusively inside the optic canal. In both cases, the histological diagnosis was schwannoma. Although the origin of pure intra-optic-canal schwannoma is controversial, intra-operative findings suggested that in these cases, the tumors arose from the sympathetic nerve around the ON.