A rare case of breast cancer metastasising to the nasopharynx and paranasal sinuses.

INTRODUCTION: Metastatic spread from non-head and neck tumours to the sinonasal region is exceedingly rare. We present a case of breast cancer metastasis to the nasopharynx, ethmoid and sphenoid sinuses. To date there have been only two similar cases in the literature. We discuss the diagnosis and management of such cases and propose how they may be staged. PRESENTATION OF CASE: A 75-year-old woman with past medical history of breast carcinoma, presented clinically as having a primary sinonasal malignancy. Magnetic resonance imaging (MRI) demonstrated a lesion involving the spenoid and ethmoid sinuses, nasendoscopy revealed a mass in the nasopharynx. Biopsy from clinic pointed to inverted sinonasal papilloma, however this did not fit with the MRI or the clinical picture. Repeat biopsy under image guidance revealed the lesion to be a breast cancer metastasis. DISCUSSION: An extensive literature review revealed few cases of spread to the sinonasal region from distant primary malignancy. When such cases do arise, most are from renal tumours. Breast cancer metastases usually present with signs and symptoms of disseminated disease, however our case represents a true isolated metastasis. We discuss the management of our case and suggest the use of the tumour-node-metastasis (TNM) system, in order to stage these rare isolated occurrences.
CONCLUSION: If discovered early, this rare manifestation may be managed by primary surgical resection. Metastases to the region may be more common than previously thought. A high index of suspicion should be employed, especially where there is past medical history of malignancy.