Attenuated adenomatous polyposis coli: the role of ascertainment bias through failure to dye-spray at colonoscopy

Dis Colon Rectum. 1999 Aug;42(8):1078-80. doi: 10.1007/BF02236707.


Purpose: The aim of this study is to show that the diagnosis of attenuated adenomatous polyposis coli must be made with caution and certainly only after adequate colonic examination with dye-spray.

Methods: Four patients thought to have attenuated adenomatous polyposis coli on the basis of family history and the identification of fewer than 100 polyps on simple colonoscopy underwent colonoscopy with dye-spray.

Results: All four individuals were found to have more than 100 polyps when dye-spray was used, confirming a diagnosis of classical familial adenomatous polyposis.

Conclusions: The diagnosis of familial adenomatous polyposis may be missed altogether or incorrectly assigned as attenuated adenomatous polyposis coli if dye-spray is not used at colonoscopy. Patients with a family history of familial adenomatous polyposis or colorectal cancer should be considered for dye-spray before the diagnosis of familial adenomatous polyposis is excluded or one of attenuated adenomatous polyposis coli is made.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenomatous Polyposis Coli / diagnosis*
  • Adenomatous Polyposis Coli / pathology
  • Adult
  • Colonoscopy / standards*
  • Coloring Agents*
  • Diagnosis, Differential
  • False Negative Reactions
  • Female
  • Humans
  • Male
  • Sensitivity and Specificity


  • Coloring Agents