Isolated low grade pilocytic astrocytoma of the optic nerve in the elderly: case report.

A 68-year-old man presented with a history of a right optic glioma. Eighteen months ago he underwent a lateral orbitotomy at another institution for removal of an optic nerve mass. At that time histology revealed that the tumor was an optic nerve glioma with a pilocytic pattern. No further treatment was instituted and one year after surgery he noticed that his right eye was proptotic again. Magnetic resonance imaging of the orbit showed that his right orbit was almost completely filled with a mass which extended through the optic canal to the chiasma. The tumor was excised by a combined neurosurgical and orbital approach. Histology proved that the neoplasm was a low grade pilocytic astrocytoma of the optic nerve.