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World J Gastroenterol. Sep 14, 2016; 22(34): 7754-7759
Published online Sep 14, 2016. doi: 10.3748/wjg.v22.i34.7754
Sessile serrated adenoma/polyps: Where are we at in 2016?
Rajvinder Singh, Leonardo Zorrón Cheng Tao Pu, Doreen Koay, Alastair Burt
Rajvinder Singh, Gastroenterology Department, Lyell McEwin and Modbury Hospital, NALHN School of Medicine, University of Adelaide, SA 5112, Australia
Leonardo Zorrón Cheng Tao Pu, Gastrointestinal Endoscopy Division, Department of Gastroenterology, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-000, Brazil
Leonardo Zorrón Cheng Tao Pu, Gastroenterology Department, Lyell McEwin and Modbury Hospital, University of Adelaide, SA 5000, Australia
Doreen Koay, Gastroenterology Department, Lyell McEwin and Modbury Hospital, University of Adelaide, SA 5000, Australia
Alastair Burt, Executive Dean, Faculty of Health Sciences, University of Adelaide, SA 5000, Australia
Author contributions: Singh R, Koay D and Zorrón Cheng Tao Pu L contributed to this paper with conception and design of the study, literature review and analysis and drafting; all authors contributed with critical revision and editing, and final approval of the final version.
Conflict-of-interest statement: No potential conflicts of interest. No financial support.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Rajvinder Singh, MBBS, MPhil, FRACP, AM, FRCP, Chair of the AGEA, Director of Gastroenterology, Clinical Associate Professor, Lyell McEwin and Modbury Hospital, NALHN School of Medicine, University of Adelaide, Haydown Road Elizabeth Vale, SA 5112, Australia. rajvinder.singh@sa.gov.au
Telephone: +61-8-81829909 Fax: +61-8-81829837
Received: May 6, 2016
Peer-review started: May 8, 2016
First decision: June 20, 2016
Revised: July 9, 2016
Accepted: July 31, 2016
Article in press: August 1, 2016
Published online: September 14, 2016
Abstract

It is currently known that colorectal cancers (CRC) arise from 3 different pathways: the adenoma to carcinoma chromosomal instability pathway (50%-70%); the mutator “Lynch syndrome” route (3%-5%); and the serrated pathway (30%-35%). The World Health Organization has classified serrated polyps into three types of lesions: hyperplastic polyps (HP), sessile serrated adenomas/polyps (SSA/P) and traditional serrated adenomas (TSA), the latter two strongly associated with development of CRCs. HPs do not cause cancer and TSAs are rare. SSA/P appear to be the responsible precursor lesion for the development of cancers through the serrated pathway. Both HPs and SSA/Ps appear morphologically similar. SSA/P are difficult to detect. The margins are normally inconspicuous. En bloc resection of these polyps can hence be troublesome. A careful examination of borders, submucosal injection of a dye solution (for larger lesions) and resection of a rim of normal tissue around the lesion may ensure total eradication of these lesions.

Keywords: Colonoscopy, Sessile serrated adenoma/polyp, Serrated lesion, Colorectal polyps, Colorectal cancer, Polypectomy, Image enhancing endoscopy, Narrow band imaging, Endocytoscopy

Core tip: Colorectal cancers (CRC) arise from 3 pathways: adenoma to carcinoma; “Lynch syndrome”; and serrated. There are 3 types of serrated lesions namely: Hyperplastic Polyps, Sessile Serrated Adenomas/Polyps and Traditional Serrated Adenomas, the latter two are associated with CRC. A careful examination of borders, submucosal injection with dye and ensuring that a rim of normal tissue is removed is paramount.