Primary Tumor of the Optic Nerve

Since Hudson's1excellent paper tumors of the optic nerve have been divided into two main groups: intraneural tumors or tumors of the nerve stem proper and tumors of the nerve sheaths. Most present-day pathologists consider tumors of the first group to be gliomas. Endotheliomas or meningiomas and the various fibromas comprise the second group. A few instances of sarcoma and angioma have been reported, but they will be omitted in this discussion. GENERAL CONSIDERATIONS Incidence.—Primary tumor of the optic nerve occurs infrequently. According to Verhoeff,2only 300 cases had been reported prior to 1932. Subsequently, reports of only 3 or 4 cases have appeared in the literature. A survey shows that in the reported cases the tumors may be divided as follows: glioma in 80 per cent of the cases, endothelioma or meningioma in 17 per cent and fibroma in 3 per cent. Little emphasis