title: Pit pattern analysis by magnifying chromoendoscopy for the diagnosis of colorectal polyps.
abstract: OBJECTIVE
  The development of magnifying chromoendoscopy has facilitated the observation of mucosal pit patterns. This study investigated the value of this technology in predicting the histologic findings of colorectal lesions.
  
  
  METHODS
  A total of 954 colorectal polyps were included. After identifying the lesions at colonoscopy, 0.2% indigocarmine solution was sprayed and then the zoom apparatus was switched to make a magnified view of the stained crypt orifice at a maximum 100 times magnification. The observed pit patterns were classified into 6 categories (I, II, IIIL, IIIS, IV, and V) according to Kudo's classification. Type I and II were designated as non-neoplastic patterns whereas other types were neoplastic. Correlation of the pit pattern with the findings of histologic examinations of resected or biopsied polyps was performed.
  
  
  RESULTS
  There were 678 diminutive (</= 5 mm) polyps (71.1%) and 705 neoplastic polyps (73.9%), including 695 adenomas and 10 carcinomas. When comparing histologically confirmed neoplastic lesions to non-neoplastic lesions, prediction of neoplastic lesions by endoscopists based on magnifying chromoendoscopy had a sensitivity of 90.8%, a specificity of 72.7%, a positive predictive value of 90.4%, a negative predictive value of 73.6%, and an overall accuracy of 86.1%. The diagnostic accuracy for neoplastic lesions was not associated with polyp size and location but was related to the operator's experience.
  
  
  CONCLUSIONS
  Characteristic pit patterns obtained by magnifying chromoendoscopy provide useful clues for differentiation of adenomatous from non-adenomatous polyps. Used appropriately in experienced hands, this technique offers a valuable adjunct to standard colonoscopy in predicting the histologic characteristics of colorectal polyps.
authors.affiliation: Graduate Institute of Public Health, Taipei Medical University, Taipei, Taiwan.
authors.forename: Hui-Hsiung
authors.initials: HH
authors.lastname: Liu
authors.forename: Shin-Ei
authors.initials: SE
authors.lastname: Kudo
authors.forename: Jyh-Pyng
authors.initials: JP
authors.lastname: Juch
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D002277:Carcinoma / Q000175:diagnosis*; D002983:Clinical Competence; D003111:Colonic Polyps / Q000145:classification / Q000175:diagnosis*; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D004396:Coloring Agents; D006801:Humans; D007203:Indigo Carmine; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D004396:Coloring Agents; D007203:Indigo Carmine