Early stage of colonic adenocarcinoma associated with traditional serrated adenoma.

We describe a 68-year-old woman diagnosed as having a colonic adenocarcinoma associated with traditional serrated adenoma (SA) with submucosal invasion of the sigmoid colon. Colonoscopy revealed a 0-IIa+IIc colon cancer with a SA component, about 12 mm in diameter, in the sigmoid colon. She underwent laparoscopy-assisted resection of the sigmoid colon. In the resected specimen, colon cancer with mucin pools was adjacent to the SA. Cases of colonic adenocarcinoma associated with traditional SA with submucosal invasion are relatively rare. This case suggests that SA may play a role in the development of colorectal cancer.