Bilateral Iris Metastasis of Small Cell Lung Carcinoma: A Case Report and Systematic Review

Objective: To report a rare case of bilateral iris metastasis from small cell lung carcinoma (SCLC) and systematically review the literature on SCLC-associated iris metastases, with emphasis on clinical presentation, management, and outcomes. Materials and Methods: A systematic literature review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, ScienceDirect, Scopus, and Web of Science were comprehensively searched on 10 July 2025. Eligible studies included English-language reports of iris metastasis originating from SCLC in human subjects. Case report: A 58-year-old woman with previously treated SCLC developed bilateral iris metastases one year after complete remission of the primary tumor. Ophthalmic examination revealed whitish-gray, vascularized iris masses with iridocorneal angle involvement, associated with secondary angle-closure glaucoma and markedly elevated intraocular pressure (48 mm Hg) in the left eye. Cyclocryotherapy, preceded by systemic and topical antiglaucoma therapy, resulted in pain relief and a reduction in intraocular pressure; the patient died four months later due to pneumonia. Results (Systematic Review): Seventeen studies comprising 17 patients were included; the median age was 60 years, and 64.7% were male. The median interval from SCLC diagnosis to ocular presentation was 4 months, although iris metastasis was occasionally the initial or concurrent manifestation of disease. The most common presenting features were visual impairment (58.8%), ocular pain (41.2%), and elevated intraocular pressure (41.2%), while iris neovascularization (35.3%) and synechiae (29.4%) were also frequent. Bilateral involvement was reported in only one previous case. Treatment approaches were heterogeneous and included antiglaucoma therapy, systemic chemotherapy, local radiotherapy, anti-VEGF therapy, and enucleation. Among patients with available follow-up (n = 12), 58.3% died within a median follow-up of 7.5 months. Conclusions: Bilateral iris metastasis from SCLC is rare and may occur as a manifestation of recurrent disease after remission. It is an aggressive condition characterized by nonspecific ocular symptoms, variable management, and poor survival, underscoring the importance of early recognition and the need for evidence-based diagnostic and therapeutic strategies.