抄録
Peritoneal recurrence of breast cancer 10 years or more after initial surgery is very rare. We present a case of peritoneal recurrence occurring 42 years after a left breast mastectomy. The patient presented with abdominal pain and vomiting, and an abdominal computed tomography scan revealed a well-defined, ovoid mass causing intestinal obstruction. Partial resection of the ileum was performed, and the pathological diagnosis of the resected tumor was poorly differentiated adenocarcinoma. In addition, a hard tumor was observed on the left chest wall that was also found to be a poorly differentiated adenocarcinoma. Both tumors were negative for progesterone receptor and human epidermal growth factor receptor 2, but positive for estrogen receptor. A late recurrence of breast cancer was diagnosed, the postoperative course of which was uneventful. This case illustrates that an extended follow-up is required for breast cancer patients to check for late recurrence.