Iris metastasis from breast cancer successfully treated with Abemaciclib and Letrozole.

Purpose To describe a patient with an unusual presentation of iris metastasis from breast cancer and her response to systemic therapy. Methods Retrospective chart review of one patient. Results A 57-year-old woman presented with a superonasal translucent vascularized iris stromal mass with fish egg-like structures budding from the surface. High frequency anterior segment ultrasonography demonstrated a solid iris stromal mass measuring 6.0 x 3.3 x 1.9 mm. On optical coherence tomography, the egg-like structures appeared as hyperreflective spheres, some of which were detached from the main iris stromal tumor. Oncologic evaluation revealed metastatic breast cancer involving the brain and lung. She was treated with oral abemaciclib and letrozole, as well as external beam radiotherapy to the brain. The iris mass had completely regressed within 4 months and remained undetectable through 8 months follow-up. The other metastatic lesions responded well to therapy. Conclusion We report a case of iris metastasis as the presenting sign of cancer dissemination that was successfully treated with targeted systemic therapy without ocular radiotherapy.