Abstract
Metastasis to the breast from large bowel is extremely rare. We herein report a case of an early invasive sigmoid colon cancer resulted to metastasize to the lymph nodes and breast during chemotherapy after endoscopic treatment. A forty two year old female was performed endoscopic mucosal resection for a pedunculated polyp at sigmoid colon. Pathologically, cancer cells invaded to submucosa and the lymphatic invasion was positive, and then she was introduced to the different hospital for the radical surgery. However, there was no indication for surgery because of the various distant lymph node metastases, chemotherapy with mFOLFOX6 + bevacizumab had been performed. Although once complete response was obtained, after 7 months, she was relapsed and then received FOLFIRI + bevacizumab as second-line and CPT-11 + cetuximab as third-line. Two weeks later the initiation of third line, erythema, edema and induration was appeared around the left breast. Ultrasound showed the breast gland thickened generally, and the low echoic lesions were found diffusely. The enlarged lymph nodes at the axilla and the heterogeneous enhanced tumor at the left breast were detected by the CT scan. Needle biopsy showed the tumor cells mainly grew as solid cancer nests and tubular structure in the lymph vessels as lymphangitis carcinomatosa. Based on the immunostain, it was diagnosed as the breast metastasis from colon cancer. And then her general condition rapidly changed for the worse. She died one month later the breast metastasis.
