title: Polyps with different grades of dysplasia and their distribution in the colorectum.
abstract: OBJECTIVE
  To determine the role of adenomatous polyps in the development of colorectal cancers, we examined the relationship between the distribution and polyps with different grades of dysplasia (low, high), or/and cancers in the colorectum.
  
  
  METHODS
  The distribution of 527 polyps with low-grade dysplasia was compared with that of 121 polyps with high-grade dysplasia, and 10 colorectal cancer lesions with adenomatous polyps in 361 patients who underwent total colonoscopy.
  
  
  RESULTS
  The distribution rate of polyps at the distal colon and rectum into polyps with high-grade dysplasia significantly increased in comparison to that into polyps with low-grade dysplasia, respectively (p<0.002). The percentage of polyps with high-grade dysplasia measuring >1 cm significantly increased in comparison to that with low-grade dysplasia measuring >1 cm (p<0.00001). In patients with both adenomatous polyps and colorectal cancers, the polyps with high-grade dysplasia at the distal sites of cancerous lesions increased significantly more than at the proximal sites of cancerous lesions (p<0.05). Polyps with high-grade dysplasia have malignant potentials to intermediate between polyps with low-grade dysplasia and colorectal cancers in our study.
  
  
  CONCLUSIONS
  The different distributions of different grades thus suggested that polyps with different grades of dysplasia at various colorectal sites were found to have different malignant potentials for cancer development.
authors.affiliation: Department of Gastroenterology, Shin-Nakama Hospital, Nakama, Japan. iki.surg@vesta.ocn.ne.jp
authors.forename: Manabu
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mine
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kusumoto
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Maehara
authors.forename: Keizo
authors.initials: K
authors.lastname: Sugimachi
mesh_terms: D018256:Adenomatous Polyps / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies