Secondary intraocular extranodal natural killer/T-cell lymphoma with optic nerve involvement: a case report

A 61-year-old female with a history of extranodal natural killer/T-cell (NK/T-cell) lymphoma of the left thigh presented with a six-month history of presumed vitritis in the left eye managed by an outside provider. Diagnostic vitrectomy revealed atypical lymphocytes positive for CD3, CD7, CD56, and Epstein-Barr virus-encoded RNA, confirming the diagnosis of secondary extranodal intraocular NK/T-cell lymphoma. Initial systemic imaging showed no evidence of extraocular disease; nonetheless, systemic chemotherapy and external beam radiation therapy were recommended. The patient elected treatment with intravitreal methotrexate alone, with early improvement in visual acuity and intraocular inflammation. However, over the following three months, she developed retinal vasculitis and sub-retinal pigment epithelium infiltrates of the left eye, and abducens nerve palsy of the right eye. A week later, she developed acute worsening of symptoms in the left eye. MRI at the time demonstrated posterior optic nerve enhancement and nasal cavity involvement. Systemic and intrathecal chemotherapy was subsequently initiated. This represents a rare presentation of secondary intraocular extranodal NK/T-cell lymphoma with subsequent optic nerve involvement. The case highlights the aggressive clinical course and neurotropic potential of NK/T-cell lymphoma, underscoring the limitations of local therapy alone and the importance of early systemic evaluation and treatment.