Fig. 2.

Histology of the optic nerve from the patient’s postmortem biopsy. A) Whole mount section of optic chiasm stained with haemotoxylin & eosin (H&E) (upper panel A) and luxol fast blue with periodic acid-Shiff (LFB/PAS) (lower panel A). To the right there is loss of myelin staining secondary to tumor infiltration and necrosis. (Note: The line running through panel A in the H&E (upper) as well as the LFB/PAS (lower) represent a necessary cut in the photomicrograph order to encompass the entire nerve at low (2x) magnification; cuts were purposely made in different places. B) H&E stained section of the right side of the optic chiasm at original magnification of 20x. Infiltrating neoplastic astrocytes (arrows) and necrosis (*) have replaced myelinated axons of the optic nerve.