Pilocytic astrocytoma with anaplasia arising from the optic chiasm in a very elderly patient

An 81-year-old man presented with a 3-week history of impaired visual acuity (100/200 right eye, 2/200 left eye). He had a central scotoma (left eye) and bitemporal hemianopsia, with no abnormality in the optic discs. Cranial MRI suggested a tumor predominantly located at the optic chiasm and extending to the optic nerves, identified pathologically as pilocytic astrocytoma with anaplasia (PAA) (figure). He received temozolomide (for 14 months) and irradiation, but the tumor eventually extended to the hypothalamus. This unusual case of histologically proven PAA demonstrates an origin from the optic chiasm,1 which is extremely rare in the elderly.2