To report a case of choroidal metastasis of breast cancer that was treated with modified photodynamic therapy.

A 45-year-old woman visited our clinic with blurred vision of the right eye, which began 1 month before. The patient previously suffered from a low back pain for 1 year. The best corrected visual acuity was 20/20 in both eyes. Fundus examination revealed an elevated yellowish mass-like lesion at the superonasal area in the right eye. Ultrasonography of the right eye showed a highly echogenic choroidal mass with moderate to high internal reflectivity. Fluorescein angiography showed hypofluorescence during the prearterial and arteriovenous phase, and well circumscribed hyperfluorescence during the venous phase. Radiologic examination was performed upon suspicion of metastasis. The examination revealed breast cancer with lung, spine and ovary metastasis. Subsequently, biopsy of the breast mass revealed an invasive ductal carcinoma. Based on these results, the patient was diagnosed with choroidal metastasis from breast carcinoma. The patient received systemic chemotherapy, and modified photodynamic therapy (PDT) was performed on the metastatic choroidal mass. Six days after modified PDT, the mass size was unchanged, and serous retinal detachment developed at the macula and inferior retina. However, 22days after treatment, the mass size markedly decreased and the serous retinal detachment was improved.