Sinus involvement in breast cancer: case report.

OBJECTIVE: To report a rare and unique presentation of metastatic breast cancer. METHOD: Case report and review of related literature. RESULTS: A 62-year-old female with metastatic breast cancer, who had been free from recurrence for 4 years, presented with diplopia secondary to lateral rectus palsy. This was due to a sphenoid sinus metastasis, which was eroding into her cavernous sinus, resulting in VIth cranial nerve neuropathy. CONCLUSION: All paranasal sinuses and the orbit are potential sites for metastases. Spread to the paranasal sinuses from breast cancer has been documented previously. However, we believe this to be the only reported case with lateral rectus palsy as a result of metastasis to the sphenoid sinus in which this was the only evidence of disseminated disease. Otolaryngology clinicians need to consider metastatic disease to the sinuses in patients with a history of neoplasia, but also recognise that tamoxifen treatment can itself cause visual disturbance.