Presumed Bilateral Vitreoretinal Metastasis Mimicking Occlusive Retinal Vasculitis in Metastatic Lung Adenocarcinoma

Purpose: To describe an unusual presentation of presumed bilateral vitreoretinal metastasis from metastatic lung adenocarcinoma mimicking occlusive retinal vasculitis and to highlight the role of multimodal imaging in the diagnostic workup. Case presentation: A 48-year-old woman with metastatic lung adenocarcinoma presented with progressive floaters and photopsias. Ophthalmic examination revealed bilateral occlusive retinal vasculitis with vascular sheathing, retinal hemorrhages, cotton-wool spots and superficial white plaque-like retinal lesions. Ultra-widefield fluorescein angiography demonstrated extensive retinal ischemia, while optical coherence tomography showed hyperreflective superficial retinal plaques and vitreous hyperreflective foci. Extensive infectious, inflammatory and autoimmune investigations were negative. In the context of progressive metastatic disease and characteristic multimodal imaging findings, a presumptive diagnosis of bilateral vitreoretinal metastasis was established. Vitreous biopsy was inconclusive because of insufficient material for cytological analysis. Following initiation of systemic trastuzumab deruxtecan, the patient showed stabilization of visual acuity, marked regression of the retinal lesions and vitreous inflammation, and improvement on multimodal imaging, paralleling systemic disease control. Conclusions: Vitreoretinal metastasis should be considered in patients with advanced malignancy presenting with atypical bilateral retinal vasculopathy. This case expands the spectrum of ophthalmic manifestations of vitreoretinal metastasis by demonstrating bilateral occlusive retinal vasculitis as a presenting phenotype and emphasizes the value of multimodal imaging in raising diagnostic suspicion. The close correlation between ocular and systemic responses suggests that retinal findings may serve as an adjunctive biomarker of systemic treatment response.