Esophageal metastasis of breast cancer during endocrine therapy for pleural dissemination 21 years after breast surgery: a case report

BACKGROUND: The esophageal metastasis of breast cancer is rare. Moreover, it is extremely unusual for patients to experience the symptoms of esophageal metastasis during their lifetimes. We present a case of dysphagia caused by esophageal metastasis after a long interval following a primary mastectomy. CASE PRESENTATION: A 77-year-old woman with a history of heterochronous bilateral breast cancer and under treatment for pleural dissemination recurrence originating from right breast cancer complained of dysphagia. At the age of 56, she had undergone a right radical mastectomy for right breast cancer. The histopathological findings revealed invasive ductal carcinoma, pT3N1M0, which was estrogen receptor (ER)- and progesterone receptor (PgR)-positive. At the age of 73, she underwent a second operation, a left modified radical mastectomy. The histopathological examination revealed invasive ductal carcinoma, pT1N0M0, which was negative for ER, PgR, and human epidermal growth factor receptor 2 (HER2). Four years after completion of adjuvant therapy for the left breast cancer, pleural effusion on her left side was observed and histopathological examination of a sample revealed pleural dissemination resulting from the right breast cancer. After initiation of therapy for recurrence, she developed dysphagia and, therefore, underwent an upper gastrointestinal tract endoscopic examination. The examination revealed whole circumferential stenosis and a band unstained by Lugol’s solution located 30 cm from her incisors. Examination of a biopsy specimen revealed a subepithelial luminal structure and dysplastic cells. Immunostaining was positive for CK7 and negative for CK20; furthermore, the sample was ER and PgR-positive. Considering the pathological findings, the patient was diagnosed with esophageal metastasis of her right breast cancer. CONCLUSIONS: Metastatic lesions in the esophagus are often located in the submucosa; therefore, they may not be definitively diagnosed by histopathological examination of mucosal biopsy specimens. Esophageal metastasis originating from breast cancer often occurs as a part of multiple organ metastases; however, esophageal metastasis is usually not considered a prognostic factor for patients. Therefore, treatment should be determined according to the severity of the other metastatic sites and the degree of esophageal stenosis.