Abstract
The patient was a 47-year-old woman. She had undergone mastectomy with axillary lymph node dissection for left breast cancer 5 years earlier. Additionally, postoperative chemotherapy and radiotherapy had been performed. She complained of abdominal pain and bloating, and visited a nearby clinic. She was referred to our hospital after ileus due to rectal tumor was suggested on abdominal CT. Colonoscopy showed entire circumferential stenosis at the mid-lower rectum, without neoplastic lesions of the mucosa. Endoscopic ultrasound-guided fine needle aspiration of the rectal tumor was performed, and the biopsy specimen suggested adenocarcinoma. CT showed entire circumferential wall thickening of the rectum and swelling of regional lymph nodes, without distant metastasis. We considered rectal metastasis due to breast cancer, but no definitive preoperative diagnosis was reached. We performed surgery due to ileus immediately. Operative findings revealed peritoneal dissemination and tumor invasion with a focus on the rectal posterior wall extending to the sacrum. Based on these findings, we performed Hartmann's operation. Finally, rectal metastasis from breast cancer was diagnosed histopathologically. Here, we report a rare case of rectal metastasis from breast cancer with reference to the literature.
