[A case of breast metastasis of gastric cancer].

We report a rare case of breast metastasis of gastric cancer in a 61-year-old female. She was diagnosed as primary gastric cancer with peritoneal dissemination and received systemic chemotherapy after distal gastrectomy for a primary lesion. A tumor developed in her right breast 4 years after the surgery, and was confirmed to be the metastasis from gastric cancer by aspiration cytology. In Japan, there are 25 reports of breast metastasis from gastric cancer. Two possible pathways from gastric lesion were lymphatic and one vascular, but the mechanism of breast metastasis has remained controversial.