title: Diagnostic performance of Japan NBI Expert Team classification for differentiation among noninvasive, superficially invasive, and deeply invasive colorectal neoplasia.
abstract: OBJECTIVE
  The Japan NBI Expert Team (JNET) classification is the first universal narrow-band imaging magnifying endoscopic classification of colorectal tumors. Considering each type in this classification, the diagnostic ability of Type 2B is the weakest. Generally, clinical behavior is believed to be different in each gross type of colorectal tumor. We evaluated the differences in the diagnostic performance of JNET classification for each gross type (polypoid and superficial) and examined whether the diagnostic performance of Type 2B could be improved by subtyping.
  
  
  METHODS
  We analyzed 2933 consecutive cases of colorectal lesions, including 136 hyperplastic polyps/sessile serrated polyps, 1926 low-grade dysplasias (LGDs), 571 high-grade dysplasias (HGDs), and 300 submucosal (SM) carcinomas. We classified lesions as polypoid and superficial type and compared the diagnostic performance of the classification system in each type. Additionally, we subtyped Type 2B into 2B-low and 2B-high based on the level of irregularity in surface and vessel patterns, and we evaluated the relationship between the subtypes and histology, as analyzed separately for polypoid and superficial types. We also estimated interobserver and intraobserver variability.
  
  
  RESULTS
  The diagnostic performance of JNET classification did not differ significantly between polypoid and superficial lesions. Ninety-nine percent of Type 2B-low lesions were LGDs, HGDs, or superficial submucosal invasive (SM-s) carcinomas. In contrast, 60% of Type 2B-high lesions were deep submucosal invasive (SM-d) carcinomas. The results were not different between each gross type. Interobserver and intraobserver agreements for Type 2B subtyping were good, with kappa values of .743 and .786, respectively.
  
  
  CONCLUSIONS
  Type 2B subtyping may be useful for identifying lesions that are appropriate for endoscopic resection. JNET classification and Type 2B sub classification are useful criteria, regardless of gross type.
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kyoku
authors.initials: K
authors.lastname: Sumimoto
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Shigita
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Hirano
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Tamaru
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ninomiya
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Oka
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Arihiro
authors.affiliation: Department of Human Sciences, Faculty of Humanities and Human Sciences, Hiroshima Shudo University, Hiroshima, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Shimamoto
authors.affiliation: Health Service Center, Hiroshima University, Hiroshima, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Yoshihara
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000236:Adenoma / Q000145:classification / Q000000981:diagnostic imaging / Q000473:pathology; D018256:Adenomatous Polyps / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D002277:Carcinoma / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D003111:Colonic Polyps / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D007564:Japan; D062048:Narrow Band Imaging; D009361:Neoplasm Invasiveness