Breast metastasis from nasopharyngeal carcinoma: A case report and review of the literature.

Although often localized at diagnosis, nasopharyngeal carcinoma (NPC) has an established potential for distant metastasis. Breast metastasis from NPC is an uncommon presentation. In the present case study, the fifth reported case of breast metastasis from NPC is presented and the use of Epstein-Barr virus testing is demonstrated for the confirmation of this diagnosis. A 49-year-old female was diagnosed with advanced NPC and developed a unilateral breast mass. The biopsy was indicative of a primary breast carcinoma. Subsequent Epstein-Barr virus testing was positive in the primary tumor and the breast mass, establishing the true diagnosis of NPC metastasis to the breast. In summary, breast metastasis from NPC is an uncommon presentation and Epstein-Barr virus testing is suitable for confirmation of the diagnosis and exclusion of primary breast cancer.