The serrated neoplasia pathway.

The concept of a 'serrated neoplasia pathway' refers to a pattern of progression of neoplasms of the colon and rectum that involves hyperplastic polyps and serrated adenomas and which results in the development of carcinoma. The existence of this pathway was initially suggested on morphological grounds. Over the past few years, the increasing recognition of biological and genetic similarities in lesions of this pathway has served to reinforce this concept. The likely existence of such a distinct pathway of colorectal carcinogenesis has implications for the practice of surgical pathology. Most notably, it requires pathologists to recognise the entity of the serrated adenoma, and also to recognise those features of hyperplastic polyps that may be associated with a potential for neoplastic progression.