Lymphoma of the orbit masquerading as Tolosa-Hunt syndrome

BACKGROUND Tolosa-Hunt syndrome is a rare clinical syndrome characterized by painful ophthalmoplegia and ipsilateral cranial neuropathies. It is caused by an inflammatory process of unknown etiology. CASE PRESENTATION We present a case of a 77-year-old white man with history of Waldenstrom's macroglobulinemia transforming to large B-cell lymphoma who presented to a community physician complaining of 4 months of isolated right retro-orbital pain and later with diplopia, ptosis, 6th nerve and pupil-sparing partial 3rd nerve palsies as well as progressive neurological findings. His clinical course was complicated by debilitating neurological symptoms and multiple hospitalizations leading to a delay in diagnosis caused by incomplete initial workup. CONCLUSION This case is a reminder that lymphoproliferative disorders often mimic other neurologic disorders and that Tolosa-Hunt is a rare diagnosis that must be considered a diagnosis of exclusion.