Isolated lymphoma of the anterior visual pathway diagnosed by optic nerve biopsy.

A 72-year-old previously healthy man developed rapidly progressive visual loss, and brain imaging showed features suggestive of a malignant glioma of the anterior visual pathway. Biopsy of one optic nerve yielded a diagnosis of lymphoma. There was no evidence of an extracranial non-Hodgkin lymphoma, so the conclusion was that this represented a primary central nervous system lymphoma (PCNSL). PCNSL isolated to the optic chiasm has been described only once in an immunocompetent patient. Our patient is unusual in that the lymphoma involved the optic nerve, chiasm, and tract in an immunocompetent patient.