A case of advanced colonic cancer that developed from residual laterally spreading tumor treated by piecemeal endoscopic mucosal resection.

This case report showed a laterally spreading tumor treated by endoscopic mucosal resection that developed as an advanced colon cancer. A 74-year-old female was visited to treat a colon tumor that was pointed out at another hospital. Total colonoscopy revealed a laterally spreading tumor (LST) 25 mm in diameter in the cecum. The lesion was diagnosed as homogenous granular type LST (G-type LST) and treated by endoscopic piecemeal mucosal resection in January 2004. A tumor was recognized by follow-up endoscopic examination in April 2006. The scar of endoscopic piecemeal mucosal resection had developed to advanced colon cancer and was treated by laparoscopy-associated ileocecal resection with D3 lymph node resection. Previous reports indicated that G-type LST in the colon could be treated by piecemeal resection, but this report suggests that G-type LST resected by piecemeal endoscopic mucosal resection might develop to advanced colon cancer.