Epstein-Barr Virus-Associated Primary Vitreoretinal B-Cell Lymphoma in a Patient Receiving Tofacitinib and Methotrexate for Psoriatic Arthritis

PURPOSE: To describe a rare case of Epstein-Barr virus (EBV)-associated primary vitreoretinal B-cell lymphoma in a patient receiving tofacitinib and methotrexate for psoriatic arthritis, highlighting the diagnostic challenges and clinical implications of iatrogenic immunosuppression. METHODS: A 42-year-old man on combined tofacitinib and methotrexate therapy presented with recurrent vitritis refractory to corticosteroid treatment. Diagnostic investigations included aqueous and vitreous polymerase chain reaction (PCR) testing for viral DNA, flow cytometry for lymphoid clonality, and systemic imaging to exclude extraocular disease. RESULTS: PCR testing confirmed the presence of EBV DNA in both aqueous and vitreous samples, while flow cytometry demonstrated a monoclonal B-cell population consistent with lymphoma. Systemic evaluation revealed no evidence of extraocular involvement. Following diagnostic pars plana vitrectomy, intraocular inflammation resolved without the need for chemotherapy, and the patient remains disease-free under close surveillance. CONCLUSION: EBV-associated primary vitreoretinal lymphoma may arise in the context of combined methotrexate and JAK inhibitor therapy. This case highlights the importance of considering masquerade syndromes in steroid-refractory uveitis, incorporating EBV PCR testing into diagnostic workup, and recognizing the potential role of immunosuppression in ocular lymphomagenesis.