乳癌發生食道轉移是很罕見的。本文報告一位59歲的女性病人，於2009年被診斷出左側乳癌，經化學治療、改良型乳房根除術及放射線治療，且持續於本院門診接受四年多的定期追蹤，期間並無明顯的復發情形。2013年9月病人因為吞嚥困難轉診來本院腸胃科門診，醫師安排食道造影、胃鏡及電腦斷層，發現食道中段有因外來的壓迫造成狹窄，病理報告證實為乳癌的食道轉移。經過荷爾蒙治療、放射治療及標靶藥物治療，吞嚥困難症狀明顯緩解。此病例可提醒醫師對乳癌病人的追蹤及照顧，應注意罕見的轉移性癌症的可能性，並了解吞嚥困難可能的原因及鑑別診斷，以免錯失及延誤病患的診斷及治療時機。

Esophageal metastasis of primary breast cancer is rare. This article reports a 59-year-old female patient diagnosed with left breast cancer in 2009. The patient had since undergone chemotherapy, modified radical mastectomy, and radiation therapy, and continued to receive regular follow-ups at our outpatient clinic for approximately four years without apparent tumor recurrence. In September 2013, she visited our gastroenterology clinic because of dysphagia. Barium esophagogram, panendoscopy, and computerized tomography were performed and identified a stricture in her middle third of esophagus caused by external compression. Pathological report indicated esophageal metastasis of breast cancer. After hormone therapy, radiation therapy and targeted therapy (using trastuzumab), her dysphagia was significantly alleviated. We present this case to remind primary care physicians to pay more attention to the possibility of rare metastatic cancer and to understand the possible causes and differential diagnosis of dysphagia, so as to avoid misdiagnosing and delaying the treatment of patients.