Published online Mar 14, 2015. doi: 10.3748/wjg.v21.i10.2896
Peer-review started: July 7, 2014
First decision: August 6, 2014
Revised: August 25, 2014
Accepted: October 14, 2014
Article in press: October 15, 2014
Published online: March 14, 2015
Processing time: 252 Days and 13.1 Hours
In recent years, a second pathway for colonic carcinogenesis, distinct from the adenomatous pathway, has been explored. This is referred to as serrated pathway and includes three types of polyp, characterised by a serrated appearance of the crypts: hyperplastic polyps (HP), sessile serrated adenomas (SSA) or lesions, and traditional serrated adenomas. Each lesion has its own genetic, as well as macroscopic and microscopic morphological features. Because of their flat aspect, their detection is easier with chromoendoscopy (carmin indigo or narrow-band imaging). However, as we show in this review, the distinction between SSA and HP is quite difficult. It is now recommended to resect in one piece as it is possible the serrated polyps with a control in a delay depending on the presence or not of dysplasia. These different types of lesion are described in detail in the present review in general population, in polyposis and in inflammatory bowel diseases patients. This review highlights the need to improve characterization and understanding of this way of colorectal cancerogenesis.
Core tip: The serrated lesions belong to a new carcinogenesis way of colorectal cancer which is important to know and detect. Even though endoscopic techniques have improved, some difficulties remain in terms of detection because of the lesions’ shape and aspect and the fact that the endoscopists have to be aware of some characteristics. However, we argue in this article that the endoscopists have to be trained so the recognition of these pre-neoplastic lesions can be improved. Furthermore, there is a necessity to communicate well with the pathologists. This article is a review of the knowledge we currently have of serrated lesions, and their endoscopic and histologic aspects which every gastroenterologist needs to know.