Breast Cancer Metastasis to the Optic Nerve: A Case Report.

Optic nerve metastases from breast cancer are an extremely rare event, with very limited cases reported in the literature. In this report, we present the case of a 64-year-old woman with a history of hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative invasive lobular carcinoma of the breast, who developed bilateral progressive vision loss almost 10 years after her initial diagnosis. Despite previous treatment using surgery, chemotherapy, radiotherapy, and hormone therapy, the progression of the disease included brain, lung, and bone metastases. The patient suffered from blurred vision that rapidly worsened, leading to complete blindness. Bilateral optic atrophy was noted on ophthalmological evaluation, and MRI findings included nodular thickening and enhancement of the pre-chiasmatic optic nerves, which were consistent with metastatic involvement. Due to her poor general condition, she was put on weekly paclitaxel systemic chemotherapy, with no indication for surgery. This is a unique case, as it highlights optic nerve metastasis as a late manifestation of lobular breast cancer and underlines the significance of considering metastatic disease in patients with newly presenting visual symptoms and a history of breast cancer. The main lesson to be learned from this report is that early detection and multidisciplinary evaluation are crucial to optimize the patient's care, despite the fact that therapeutic options may be limited at an advanced stage of the disease.