Choroidal Involvement in Nodal Marginal Zone Lymphoma Presenting as Serous Retinal Detachment.

PURPOSE: To describe the clinical presentation and multimodal imaging findings of choroidal involvement in nodal marginal zone lymphoma (NMZL) presenting as serous retinal detachment and its response to systemic chemotherapy. METHODS: Retrospective review of clinical records and multimodal imaging findings, with joint interpretation by a uveitis specialist and the hematology-oncology team. RESULTS: A 63-year-old woman presented with decreased vision in the left eye and was found to have a shallow serous retinal detachment. Inflammatory choroiditis was initially suspected and systemic corticosteroids therapy was initiated, resulting in transient improvement. Subsequent examination revealed recurrent subretinal fluid with multiple subretinal yellow infiltrates and diffuse choroidal thickening after the steroid effect subsided. Optical coherence tomography demonstrated undulating retinal pigment epithelium. Choroidal lymphoma was considered, prompting thorough systemic investigation. Systemic imaging later identified axillary and intra-abdominal lymphadenopathy and a right breast mass. Histopathology of the breast lesion confirmed NMZL. The patient was treated with rituximab-based systemic chemotherapy with intrathecal chemotherapy, achieving partial systemic response and complete ocular remission. CONCLUSIONS: Choroidal involvement in NMZL is rare and may present as steroid-responsive but recurrent serous retinal detachment, mimicking inflammatory disease. Systemic evaluation with biopsy of accessible extraocular sites, in conjunction with compatible ocular findings, can establish the diagnosis while avoiding high-risk choroidal biopsy. Early recognition and multidisciplinary collaboration are essential to enable timely diagnosis and systemic treatment.