title: Pressure dye-spray: a simple and reliable method for differentiating adenomas from hyperplastic polyps in the colon.
abstract: BACKGROUND
  Based on 10 years of experience with chromoendoscopy, our hypothesis was that colonic adenomas can be differentiated from hyperplastic polyps by use of a high-pressure spray-jet of dye (pressure dye-spray). To test the accuracy of pressure dye-spray, classification of colonic polyps as adenomas and hyperplastic polyps by pressure dye-spray and ordinary colonoscopic findings (shape, size, and color surface appearance) were compared.
  
  
  METHODS
  Pressure dye-spray chromoendoscopy was performed by using 0.035% indigo carmine, a spray-type cannula, and a water pump. Polyps were first classified as adenomas or hyperplastic polyps by ordinary colonoscopic findings. One or more pressure dye-spray bursts were then focused on the polyp from a distance of 1 to 2 cm. Polyps were classified as adenomas only if oozing of blood was evident; otherwise, they were classified as hyperplastic polyps. A histologic diagnosis was obtained for all polyps, and the results of ordinary colonoscopic findings and pressure dye-spray were compared.
  
  
  RESULTS
  This study examined 1468 polyps (1201 adenomas, 267 hyperplastic polyps; mean diameter 4 mm). The sensitivities for polyp differentiation with pressure dye-spray and ordinary colonoscopic findings were, respectively, 97.9% and 73.4% (p < 0.0001); specificities were, respectively, 96.6% and 92.1% (p = 0.077).
  
  
  CONCLUSIONS
  Pressure dye-spray was found to be a reliable technique for differentiation between adenomas and hyperplastic polyps.
authors.affiliation: Endoscopy Unit, Daiyukai Daiichi Hospital, Ichinomiya, Aichi, Japan.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Kanamori
authors.forename: Makoto
authors.initials: M
authors.lastname: Itoh
authors.forename: Naoki
authors.initials: N
authors.lastname: Yoshimi
mesh_terms: D000236:Adenoma / Q000473:pathology*; D015331:Cohort Studies; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy; D004396:Coloring Agents; D003937:Diagnosis, Differential; D006801:Humans; D006965:Hyperplasia / Q000473:pathology*; D007203:Indigo Carmine; D011312:Pressure; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004396:Coloring Agents; D007203:Indigo Carmine