title: Endoscopic characterization of sessile serrated adenomas/polyps with and without dysplasia.
abstract: OBJECTIVE
  Sessile serrated adenomas/polyps (SSA/Ps) are precursors of colorectal cancer (CRC), but their endoscopic detection can be difficult. We therefore examined the endoscopic characteristics of SSA/Ps with and without dysplasia in a cross-sectional study.
  
  
  METHODS
  We reviewed clinical, endoscopic, and histopathologic data from patients undergoing colonoscopy between February 2008 and February 2012. We categorized colorectal polyps according to anatomic site, size, and shape, and classified serrated polyps using the World Health Organization (WHO) classification. Multiple logistic regression analyses examined potential differences regarding site, size, and shape between SSA/Ps and colorectal adenomas (overall and advanced only).
  
  
  RESULTS
  We examined 7433 patients (mean age 59 years, 45.9 % men) with 5968 colorectal polyps. In total, we found 170 SSA/Ps (170/5968, 2.9 %), including 63 SSA/Ps with dysplasia (1.1 %) and 107 SSA/Ps without dysplasia (1.8 %). Compared with SSA/Ps with dysplasia, SSA/Ps without dysplasia were more often proximally located (odds ratio [OR] 3.3, 95 % confidence interval [95 %CI] 1.7 - 6.4), but less often < 6 mm in size (OR 0.6, 95 %CI 0.3 - 1.1). No significant differences were found regarding location between SSA/Ps with dysplasia and advanced adenomas (proximal colon, 47.6 % vs. 40.1 %). However, SSA/Ps with dysplasia were more often < 6 mm in size than advanced adenomas (OR 0.3, 95 %CI 0.2 - 0.5). Of the 63 dysplastic SSA/Ps, 6 (9.5 %) contained high grade dysplasia, but none invasive carcinoma.
  
  
  CONCLUSIONS
  SSA/Ps with dysplasia are frequently < 6 mm in size, located throughout the colon and 9.5 % of them contain high grade dysplasia. These findings underscore the importance of high quality colonoscopic examination to maximize protection against CRC.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Maastricht University Medical Center, the Netherlands.
authors.forename: Mariëlle W E
authors.initials: MW
authors.lastname: Bouwens
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Maastricht University Medical Center, the Netherlands.
authors.forename: Yasmijn J
authors.initials: YJ
authors.lastname: van Herwaarden
authors.affiliation: Department of Methodology and Statistics, Maastricht University Medical Center, the Netherlands.
authors.forename: Bjorn
authors.initials: B
authors.lastname: Winkens
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Maastricht University Medical Center, the Netherlands.
authors.forename: Eveline J A
authors.initials: EJ
authors.lastname: Rondagh
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Maastricht University Medical Center, the Netherlands.
authors.forename: Rogier
authors.initials: R
authors.lastname: de Ridder
authors.affiliation: Department of Pathology, Maastricht University Medical Center, the Netherlands.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Riedl
authors.affiliation: Department of Pathology, Maastricht University Medical Center, the Netherlands.
authors.forename: Ann
authors.initials: A
authors.lastname: Driessen
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, the Netherlands.
authors.forename: Evelien
authors.initials: E
authors.lastname: Dekker
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Maastricht University Medical Center, the Netherlands.
authors.forename: Ad A M
authors.initials: AA
authors.lastname: Masclee
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Maastricht University Medical Center, the Netherlands.
authors.forename: Silvia
authors.initials: S
authors.lastname: Sanduleanu
mesh_terms: D000236:Adenoma / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000473:pathology*; D047368:Tumor Burden