title: Adenocarcinoma in an ano-vaginal fistula in Crohn's disease.
abstract: BACKGROUND
  Fistulas are a relatively common occurrence in Crohn's disease (CD), and often present early in the disease process. Additionally, patients suffering from either CD or ulcerative colitis are shown to have an increased risk of colorectal malignancies compared with the general population.
  
  
  METHODS
  We present a case of adenocarcinoma in an ano-vaginal fistula in a patient with longstanding CD.
  
  
  CONCLUSIONS
  Various pathogenic mechanisms for the development of carcinoma in fistulas have been suggested, but there is no consensus and indeed this risk may be cumulative. In this case report, we also discuss the pathogenesis of mucinous adenocarcinoma in fistulas secondary to CD.
  
  
  CONCLUSIONS
  Better detection of adenocarcinoma in patients presenting with persistent non-resolving fistulas in the presence of CD should be undertaken with regular biopsies following examinations under anaesthetic of the anorectum.
authors.affiliation: Hillingdon Hospital NHS Foundation Trust, United Kingdom. Electronic address: m.alfa-wali@imperial.ac.uk.
authors.forename: Maryam
authors.initials: M
authors.lastname: Alfa-Wali
authors.forename: Angela
authors.initials: A
authors.lastname: Atinga
authors.forename: Yasser
authors.initials: Y
authors.lastname: Mohsen
authors.forename: Andrew
authors.initials: A
authors.lastname: Anthony
authors.forename: Alistair
authors.initials: A
authors.lastname: Myers