Low frequency of colorectal dysplasia in patients with long-standing inflammatory bowel disease colitis: detection by fluorescence endoscopy

Endoscopy. 2006 May;38(5):477-82. doi: 10.1055/s-2006-925165.


Background and study aim: 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.

Patients and 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.

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Aminolevulinic Acid / administration & dosage
  • Biopsy
  • Colitis / pathology*
  • Colonoscopy / methods*
  • Colorectal Neoplasms / pathology*
  • Diagnosis, Differential
  • Female
  • Fluorescence
  • Humans
  • Male
  • Middle Aged
  • Photosensitizing Agents / administration & dosage
  • Precancerous Conditions / pathology*


  • Photosensitizing Agents
  • Aminolevulinic Acid