Therapeutic Changes in Bilateral Choroidal Metastasis from Non-Small Cell Lung Cancer with Response to Afatinib: A Case Report

A 49-year-old male presented with a three-day onset of blurred vision and metamorphopsia in the left eye. Fundoscopy and OCT images identified multiple subretinal masses with associating serous retinal detachment in both eyes. Bilateral choroidal metastasis was suspected, and further evaluation revealed a mass in the lower left lobe of the lung with multiple metastatic loci. Ultimately, the patient was diagnosed with Stage IVB (T2aN2M1c) adenocarcinoma of the lung. Genetic analysis revealed an exon 19 deletion mutation in the epidermal growth factor receptor (EGFR) gene. The patient was started on afatinib, a second-generation tyrosine kinase inhibitor. Drastic improvement in both tumor volume and visual acuity was observed after 1.5 months. The primary site and other metastatic loci also improved significantly during the observed period. Our report demonstrated the effectiveness of afatinib alone for the treatment of bilateral choroidal metastasis in a non-small cell lung cancer patient exhibiting EGFR mutation.