A case report: long-term survival cases of nasopharyngeal carcinoma with breast metastasis.

Background: Metastatic malignancies in the breast most commonly originate from cancers of adjacent organs, including lymphoma, melanoma, and lung cancers, while metastases from distant primary sites, including gastrointestinal, head and neck, and pelvic malignancies, are less likely to metastasize to the breast. Nasopharyngeal carcinoma (NPC) with breast metastases is rare. This report describes a patient with pathologically confirmed NPC with breast metastasis who achieved favorable treatment outcomes. Case presentation: A 50-year-old Chinese man with a history of NPC developed multiple systemic metastases. Histopathological examination of a breast lesion confirmed NPC metastasis. After systemic chemotherapy combined with immunotherapy, the patient achieved disease remission and was alive at the time of reporting. Conclusion: This case also serves as a reminder of the importance of re-biopsy for recurrent or metastatic lesions. These observations emphasize the need for further research regarding uncommon metastatic patterns of NPC to refine treatment strategies and improve clinical outcomes.