To report a case of choroidal metastasis caused by lung cancer in a young female who had no history.

A 31-year-old female presented with decreased vision for 1 week. Fundus examination revealed an orange colored choroidal tumor and serous retinal detachment at superotemporal area of the optic disc on the left eye. On chest X-ray, atypical pneumonia or hematogenous metastasis was shown. Additionally, mammography, chest-abdomen computed tomography, lumbar magnetic resonance imaging, and transbronchial lung biopsy were performed and the patient was finally diagnosed with adenocarcinoma. The patient started systemic chemotherapy and visual acuity improved after 1 month. Tumor size and subretinal fluid also decreased. The tumor disappeared 2 months later and there was no recurrence.

There are only few cases in which choroidal metastasis was observed in a young female patient with no history who had decreased visual acuity and was later diagnosed with lung cancer. Authors report this case because a satisfactory result was obtained from chemotherapy alone.