Late metastasis to macroscopically normal paranasal sinuses from breast cancer

BACKGROUND: Breast cancer can very rarely result in late metastases to the paranasal sinuses. METHODS AND RESULTS: We present a 75-year-old woman who developed sinonasal symptoms mimicking sinusitis 20 years after receiving a breast cancer diagnosis. Rigid nasendoscopy was unremarkable, but due to persistent unilateral nasal symptoms and suspicious radiological findings, the patient underwent endoscopic biopsies of macroscopically normal sinuses which confirmed metastatic breast cancer. CONCLUSIONS: High suspicion index, a thorough history, and examination are of paramount importance as metastases to the sinuses from breast cancer can occur even 20 years after diagnosis.