title: White opaque substance within superficial elevated gastric neoplasia as visualized by magnification endoscopy with narrow-band imaging: a new optical sign for differentiating between adenoma and carcinoma.
abstract: BACKGROUND
  The microvascular pattern (MVP) as visualized by magnification endoscopy (ME) is a reliable marker for differentiating between benign and malignant gastric flat lesions. However, in cases of gastric neoplasia of 0-IIa type, it is sometimes impossible to visualize the MVP because a white opaque substance (WOS) obscures the subepithelial MVP.
  
  
  OBJECTIVE
  To investigate whether the morphology of the WOS could be a useful optical sign for discriminating between adenoma and carcinoma.
  
  
  METHODS
  Single tertiary referral center.
  
  
  METHODS
  Forty-six gastric neoplasias of only 0-IIa type (18 adenomas and 28 early carcinomas) were evaluated.
  
  
  METHODS
  The prevalence and the morphology of the WOS as visualized by ME with narrow-band imaging (NBI) according to histologic type (adenoma vs carcinoma).
  
  
  METHODS
  The WOS is more frequently present in adenomas than in carcinomas. With regard to the morphology of the WOS, 100% of the examples of WOS within adenomas demonstrated a regular distribution; in contrast, 83% of the examples of WOS within carcinomas showed an irregular distribution.
  
  
  RESULTS
  In cases in which a neoplasia of 0-IIa type showed either WOS with a regular distribution or a regular MVP, the sensitivity and specificity for discriminating adenoma from carcinoma were 94% and 96%, respectively.
  
  
  CONCLUSIONS
  The number of cases was limited. The WOS has not yet been characterized by chemical analysis.
  
  
  CONCLUSIONS
  In cases in which the WOS is observed, rather than assessing the MVP, morphologic analysis of the WOS could be an alternative new optical sign for discriminating adenoma from carcinoma when using ME with NBI.
authors.affiliation: Department of Gastroenterology, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Kenshi
authors.initials: K
authors.lastname: Yao
authors.forename: Akinori
authors.initials: A
authors.lastname: Iwashita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanabe
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Nishimata
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagahama
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Maki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takaki
authors.forename: Fumihito
authors.initials: F
authors.lastname: Hirai
authors.forename: Takashi
authors.initials: T
authors.lastname: Hisabe
authors.forename: Taku
authors.initials: T
authors.lastname: Nishimura
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Matsui
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology*; D000236:Adenoma / Q000175:diagnosis / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D015331:Cohort Studies; D003937:Diagnosis, Differential; D005260:Female; D005753:Gastric Mucosa / Q000098:blood supply / Q000473:pathology; D005773:Gastroscopy / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007150:Immunohistochemistry; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009367:Neoplasm Staging; D011336:Probability; D011858:Radiographic Magnification; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*