title: Diagnostic features of sessile serrated adenoma/polyps on magnifying narrow band imaging: a prospective study of diagnostic accuracy.
abstract: OBJECTIVE
  The narrow band imaging classification system (NBI International Colorectal Endoscopic [NICE] classification) classifies colorectal polyps very accurately. However, sessile serrated adenoma/polyps (SSA/Ps) pathologically resembles hyperplastic polyp and has a possibility to be left in situ on NICE classification. The aim of this study was to establish and evaluate new simple diagnostic features for SSA/Ps using magnifying narrow band imaging (M-NBI).
  
  
  METHODS
  We performed a single-arm observational study of diagnostic accuracy in two stages, as follows: seeking stage, development of simple diagnostic features for SSA/P and definition of diagnostic criteria based on retrospective assessments of M-NBI; and validation stage, prospective validation and evaluation of the new diagnostic criteria.
  
  
  RESULTS
  In the seeking stage, we identified brownish, oval, expanded crypt openings and thick-branched vessels on the surfaces of SSA/Ps. We named these "expanded crypt openings" (ECOs) and "thick and branched vessels" (TBVs), respectively. In the validation stage, we enrolled 796 polyps in 261 patients, and classified 126 polyps as NICE type 1; all these lesions were endoscopically removed and assessed histopathologically. The sensitivity, specificity, and accuracy of ECOs for SSA/Ps were 84.3%, 81.1%, and 82.4%, whereas those of TBVs were 45.1%, 68.9%, and 59.2%, respectively. M-NBI provided a sensitivity of 98% and specificity of 59.5% for discrimination of SSA/Ps from other lesions classified as NICE type 1.
  
  
  CONCLUSIONS
  Identification of ECOs, supplemented with TBVs, has high sensitivity for the diagnosis of SSA/P. These findings may facilitate the use of endoscopic optical diagnosis in clinical practice.
authors.affiliation: Department of Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamashina
authors.forename: Yoji
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Noriya
authors.initials: N
authors.lastname: Uedo
authors.forename: Kenji
authors.initials: K
authors.lastname: Aoi
authors.forename: Noriko
authors.initials: N
authors.lastname: Matsuura
authors.forename: Kengo
authors.initials: K
authors.lastname: Nagai
authors.forename: Fumi
authors.initials: F
authors.lastname: Matsui
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
authors.forename: Mototsugu
authors.initials: M
authors.lastname: Fujii
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Noboru
authors.initials: N
authors.lastname: Hanaoka
authors.forename: Koji
authors.initials: K
authors.lastname: Higashino
authors.forename: Ryu
authors.initials: R
authors.lastname: Ishihara
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tomita
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iishi
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology*; D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D012680:Sensitivity and Specificity
keywords: NICE classification; hyperplastic polyp; magnifying narrow band imaging; sessile serrated adenoma/polyp