Clinicopathologic features and treatment of breast metastasis from nasopharyngeal carcinoma: A report of two cases and literature review.

Breast metastasis is a rare pattern of distant metastasis from nasopharyngeal carcinoma (NPC) following curative treatment. The present study reported two patients with breast metastasis from NPC and reviewed four such patients reported in the literature, including the analysis of clinical profiles, pathological diagnoses, treatment strategies and outcomes. The breast is a potential metastatic site for patients with NPC following curative treatment; however, thus far, only metachronous breast metastasis has been reported. Infection with Epstein-Barr virus (EBV) was identified in the breast metastasis sites of the two patients investigated in the current study using in situ hybridization for EBV-encoded small RNAs. Patients with breast metastases from NPC consistently and simultaneously develop metastases in other sites. In addition, the two current patients had poor prognoses. Therefore, chemotherapy was the primary treatment strategy administered. A solitary breast metastasis was identified in the male patient. At the most recent follow-up 10 years subsequent to undergoing a Halsted mastectomy, the patient remained alive, however the patient is now lost to follow-up. This case indicates that patients exhibiting NPC with a solitary breast metastasis may still gain long-term survival by undergoing radical mastectomy; therefore, radical mastectomy should be considered in such patients.