title: Intramucosal adenocarcinoma of the ileum originated 40 years after ileosigmoidostomy.
abstract: BACKGROUND
  Small bowel adenocarcinomas (SBAs) are rare carcinomas. They are asymptomatic and usually neither endoscopy nor contrast studies are performed for screening
  
  
  METHODS
  A 72-year-old Japanese male had a positive fecal occult blood test at a regular check-up in 2006. He suffered appendicitis and received an ileosigmoidostomy in 1966. A colonoscopy revealed an irregular mucosal lesion with an unclear margin at the ileum side of the anastomosis. A mucosal biopsy specimen showed adenocarcinoma histopathologically. Excision of the anastomosis was performed for this patient. The resected specimen showed a flat mucosal lesion with a slight depression at the ileum adjacent to the anastomosis. Histological examination revealed a well differentiated intramucosal adenocarcinoma (adenocarcinoma in situ). Immunohistological staining demonstrated the overexpression of p53 protein in the adenocarcinoma.
  
  
  CONCLUSIONS
  Adenocarcinoma of the ileum at such an early stage is a very rare event. In this case, there is a possibility that the ileosigmoidostomy resulted in a back flow of colonic stool to the ileum that caused the carcinogenesis of the small intestine.
authors.affiliation: Department of Surgery, Hitachi Yokohama Hospital, 550 Totsuka-cho, Totsuka-ku, Yokohama, Kanagawa 244-0003, Japan. shinsame@me.com
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sameshima
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tomozawa
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Koketsu
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Okada
authors.forename: Hideyo
authors.initials: H
authors.lastname: Miyato
authors.forename: Misa
authors.initials: M
authors.lastname: Iijima
authors.forename: Masaru
authors.initials: M
authors.lastname: Kojima
authors.forename: Toshio
authors.initials: T
authors.lastname: Kaji
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology* / Q000473:pathology / Q000601:surgery; D000368:Aged; D001064:Appendicitis / Q000601:surgery*; D012809:Colon, Sigmoid / Q000601:surgery*; D006801:Humans; D007078:Ileal Neoplasms / Q000209:etiology* / Q000473:pathology / Q000601:surgery; D007081:Ileostomy / Q000009:adverse effects*; D008297:Male; D011183:Postoperative Complications / Q000209:etiology*