Abstract
A 41-year-old female was admitted into hospital due to recurrent abdominal pain with bloating. An enteroscopy was carried out and stenosis in the lower jejunal lumen was identified. This led to a diagnosis of small bowel obstruction caused by inflammation. During the laparotomy, the resection and anastomosis of a narrow segment of small intestine was performed. In combination with the results of immunohistochemical analysis, the postoperative pathology indicated the presence of a poorly differentiated/undifferentiated carcinoma of the small intestine, which was considered to have arisen from breast cancer. Postoperative examination showed bilateral breast masses, and the pathology of the right breast tumor biopsy prompted the diagnosis of invasive lobular carcinoma. A breast MRI was reviewed following five cycles of XT chemotherapy and the evaluation was stable disease (SD). Since the mass was not sensitive to chemotherapy, a bilateral modified radical mastectomy was performed, and postoperative pathology confirmed the mass to be primary bilateral invasive lobular carcinoma.