A 74-year-old woman experienced chronic painless progressive binocular horizontal diplopia for 2 years. Initial examination showed a visual acuity of 20/20 OU. External and slit lamp examination was unremarkable. Orthoptic evaluation showed an incomitant esotropia, a small vertical strabismus, and a large degree of excyclotorsion. Investigation revealed a diagnosis of diffuse large B-cell lymphoma.
