title: Low frequency of colorectal dysplasia in patients with long-standing inflammatory bowel disease colitis: detection by fluorescence endoscopy.
abstract: OBJECTIVE
  Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colonic dysplasias. Dysplastic changes in flat mucosa are likely to be missed by conventional colonoscopy. Endoscopic fluorescence imaging, using 5-aminolevulinic acid (5-ALA) as photosensitizer, has evolved as a new technique to differentiate between normal colonic mucosa and dysplasia. We combined this technique with random biopsies to prospectively evaluate the occurrence of dysplasias in patients with long-standing IBD.
  
  
  METHODS
  52 colonoscopies were performed in 42 consecutive patients (n = 28 with ulcerative colitis, n = 11 with Crohn's colitis, n = 3 with indeterminate colitis; mean age 43 years, range 21 - 78) with long-standing IBD colitis (median disease duration 14 years, range 3 - 40). All patients were in clinical remission. Patients were examined using both conventional white light and by fluorescence colonoscopy using oral 5-ALA. Four biopsies were taken every 10 cm from mucosa of normal appearance. In addition, macroscopically suspicious and fluorescence-positive areas were biopsied.
  
  
  RESULTS
  A total of 688 biopsies of red-fluorescent (n = 20) and nonfluorescent (n = 662) areas of mucosa were taken. Dysplasia was detected histopathologically in only two of the biopsies. These biopsies were taken from two polypoid lesions which were fluorescence-negative.
  
  
  CONCLUSIONS
  The rate of colonic dysplasia in patients with long-standing IBD colitis may be lower than previously reported.
authors.affiliation: Department of Medicine II, Klinikum Grosshadern, University of Munich, Germany. thomas.ochsenkuehn@med.uni-muenchen.de
authors.forename: T
authors.initials: T
authors.lastname: Ochsenkühn
authors.forename: C
authors.initials: C
authors.lastname: Tillack
authors.forename: H
authors.initials: H
authors.lastname: Stepp
authors.forename: J
authors.initials: J
authors.lastname: Diebold
authors.forename: S J
authors.initials: SJ
authors.lastname: Ott
authors.forename: R
authors.initials: R
authors.lastname: Baumgartner
authors.forename: S
authors.initials: S
authors.lastname: Brand
authors.forename: B
authors.initials: B
authors.lastname: Göke
authors.forename: M
authors.initials: M
authors.lastname: Sackmann
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000622:Aminolevulinic Acid / Q000008:administration & dosage; D001706:Biopsy; D003092:Colitis / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005453:Fluorescence; D006801:Humans; D008297:Male; D008875:Middle Aged; D017319:Photosensitizing Agents / Q000008:administration & dosage; D011230:Precancerous Conditions / Q000473:pathology*
chemical_list: D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid