Background: Orbital metastases are rare in breast cancer, representing only 3–10% of ocular metastases. This report highlights a case where orbital involvement was the first indicator of systemic metastatic spread. Case Presentation: A 72-year-old woman with a history of Estrogen Receptor (ER)-positive (5%), Progesterone Receptor (PR)-negative, Human epidermal growth factor receptor-2 (HER2)-negative breast cancer (diagnosed 3 years prior) presented with right orbital pain, diplopia, and periorbital swelling. Imaging revealed multiple myositis of the extraocular muscles, compressive displacement of the optic nerve, and right periorbital edema. Bone scintigraphy identified multifocal skeletal metastases. A navigation-assisted biopsy confirmed metastatic invasive ductal carcinoma, immunohistochemically consistent with the primary tumor (ER/PR-negative, HER2-negative). A systematic analysis using next-generation sequencing indicated aberrant activation of the phosphoinositide 3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway. Chemotherapy, targeted therapy and bisphosphonate therapy were initiated, with planned radiotherapy for symptomatic progression. Conclusion: Orbital symptoms in breast cancer survivors, even subtle ones, necessitate prompt evaluation for metastatic disease. Multimodal imaging (e.g., Computed Tomography (CT)/Magnetic Resonance Imaging (MRI)) combined with image-guided biopsy is critical for diagnosis. Early detection enables multidisciplinary palliative strategies to optimize quality of life while addressing systemic dissemination.
Zhu et al. (2026) studied this question.