Epidemiologic characteristics of the flat adenoma of muto - A prospective study

S. J. Lanspa, J. Rouse, T. Smyrk, P. Watson, J. X. Jenkins, H. T. Lynch

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The flat adenoma is an endoscopically visible lesion that histologically consists of adenomatous change near the luminal surface of colonic tubules. We have described three families with hereditary colon cancer with later age of onset than familial adenomatous polyposis (FAP) and with multiple proximal colonic flat adenomas. These families have been linked to the FAP locus on chromosome 5. Our aim was to determine whether the flat adenoma is pathognomonic of this hereditary flat adenoma syndrome (HFAS) or merely an atypical or early tubular adenoma with occurrence in patients other than those from colon cancer-prone families. Methods: We prospectively examined a population referred for colonoscopy within a one-year period. During colonoscopy, flat adenomas were specifically sought and all lesions were removed endoscopically and evaluated histologically. Members of known hereditary colon cancer families were excluded. Results: One hundred forty-eight patients underwent colonoscopy (64 men and 84 women). Median age was 61 years. Fifty-seven patients had 157 polyps. One hundred thirty-six polyps were reviewed histologically. Thirty-five (23.6 percent) of the referred patients had adenomas, of whom twelve patients had only flat adenomas while six had both flat and other adenomas (18=12 percent of 148). The associations between flat adenoma occurrence and various predictors (sex, race, prior colonic neoplasms, family history of cancer, synchronous adenomas) were similar to those seen with other adenomas. Flat adenomas were found in nearly equal proportions of patients under or over age 61 years (11 percent and 13 percent, respectively). Other adenomas were significantly more common in the older group (6 percentvs. 25 percent;P

Original languageEnglish (US)
Pages (from-to)543-546
Number of pages4
JournalDiseases of the Colon & Rectum
Issue number6
StatePublished - Jun 1992
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Gastroenterology


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