title: Prevalence of clinically important histology in small adenomas.
abstract: OBJECTIVE
  The prevalence of advanced histology in small polyps has become a crucial issue in optimizing colorectal cancer screening strategies, especially in view of the advent of computed tomography colonography. We evaluated the prevalence of advanced histology in small and diminutive adenomas to clarify their clinical importance in terms of malignant potential.
  
  
  METHODS
  Data were reviewed retrospectively from 3291 colonoscopies performed on asymptomatic patients found to have an adenoma on screening with flexible sigmoidoscopy a few weeks before the colonoscopy or who had a family history of colorectal cancer. All polyps were excised endoscopically and sent for pathology testing. Specimens with advanced histology were confirmed by a second reading.
  
  
  RESULTS
  Of the 3291 colonoscopies performed, 1235 colonoscopies yielded a total of 1933 small or diminutive adenomatous polyps. Advanced histology including carcinoma was found in 10.1% of small (5-10 mm) adenomas and in 1.7% of diminutive adenomas (< or = 4 mm). Carcinoma was found in .9% of small adenomas, and 0% of diminutive adenomas. Of the 107 patients found to have polyps 2-10 mm with advanced histology, 100 (93%) were referred for colonoscopy because of an adenoma found on a recent screening with flexible sigmoidoscopy. Seven patients underwent colonoscopy for a positive family history of colon cancer; all 7 had a single affected first-degree relative older than age 50.
  
  
  CONCLUSIONS
  Adenomas 5-10 mm in size harbor pathologically significant histology, and the need for removal of these lesions must be addressed to optimize colorectal cancer prevention.
authors.affiliation: Dartmouth-Hitchcock Medical Center, Gastroenterology, Lebanon, New Hampshire 03756, USA. Lynn.Butterly@Dartmouth.edu
authors.forename: Lynn F
authors.initials: LF
authors.lastname: Butterly
authors.forename: Michael P
authors.initials: MP
authors.lastname: Chase
authors.forename: Heiko
authors.initials: H
authors.lastname: Pohl
authors.forename: Gale S
authors.initials: GS
authors.lastname: Fiarman
mesh_terms: D018256:Adenomatous Polyps / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000473:pathology*; D003110:Colonic Neoplasms / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence