The majority of colorectal adenocarcinomas arise through the malignant transformation of tubular and villous adenomas. However, approximately 10-30% of colonic carcinomas have a different origin referred to as serrated neoplasia pathway.
Precursors of these tumors are serrated adenomas, which differ from the conventional adenomas histologically as well as genetically. Serrated carcinomas are predominantly found in the right half of the colon and histologically correspond to well differentiated, mucinous or trabecular colorectal adenocarcinomas with the BRAF or RAS genes mutation.