title: Adenocarcinoma at the site of ileoanal anastomosis in Crohn's disease: report of a case.
abstract: OBJECTIVE
  Proctocolectomy with ileoanal anastomosis has gained acceptance for the treatment of patients with ulcerative colitis. However, there are some patients with Crohn's disease who received ileoanal anastomosis, because some Crohn's colitis is difficult to differentiate from ulcerative colitis. The risk of cancer development at the site of ileoanal anastomosis has not been emphasized in Crohn's disease.
  
  
  METHODS
  A 12-year-old patient with Crohn's disease was treated by proctocolectomy with straight ileoanal anastomosis. Twenty-five years after the operation, the patient noticed the tumor that developed at the site of ileoanal anastomosis.
  
  
  RESULTS
  This article presents a patient with Crohn's disease who developed invasive adenocarcinoma at the site of ileoanal anastomosis 25 years after proctocolectomy with ileoanal anastomosis.
  
  
  CONCLUSIONS
  An ileoanal anastomosis does not eliminate the risk of cancer development, and surveillance after this operation seems advisable.
authors.affiliation: Department of Surgery, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kotanagi
authors.forename: H
authors.initials: H
authors.lastname: Kon
authors.forename: M
authors.initials: M
authors.lastname: Iida
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: K
authors.initials: K
authors.lastname: Koyama
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D001003:Anal Canal / Q000473:pathology / Q000601:surgery; D000714:Anastomosis, Surgical; D002648:Child; D003424:Crohn Disease / Q000473:pathology / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D007078:Ileal Neoplasms / Q000473:pathology / Q000601:surgery*; D007082:Ileum / Q000473:pathology / Q000601:surgery; D008297:Male; D009361:Neoplasm Invasiveness; D011183:Postoperative Complications / Q000473:pathology / Q000601:surgery*; D012086:Reoperation