EGFR and lung adenocarcinoma: <h4>Purpose</h4>We report a unique case of iris metastasis from epidermal growth factor receptor (EGFR)-positive lung adenocarcinoma, diagnosed solely by cytologic analysis of aqueous humor without tissue biopsy.<h4>Observations</h4>A 56-year-old man with a known history of lung adenocarcinoma presented with unilateral iris masses, anterior chamber inflammation, and secondary glaucoma.