Fig. 9. Optic nerve glioma. Optic nerve (below) has been replaced by proliferating astrocytes. Tumor cells (above) fill the distended subdural space (H & E, × 63) Inset. Arachnoidal hyperplasia where the nerve inserts into the globe. (H E, × 25; Courtesy of Drs. Eggers, Jakobiec, and Jones)