title: Osseous metaplasia in an ulcerating tubular adenoma of the colon: a case report.
abstract: BACKGROUND
  Heterotopic bone is rarely found in the gastrointestinal tract. Here we report a rare case of metaplastic ossification within a benign ulcerating adenoma and review the literature concerning the aetiology.
  
  
  METHODS
  A 63-year-old woman, who presented with a history of melaena, was found at colonoscopy to have a pedunculated ulcerating polyp. Histological examination demonstrated multiple areas of osseous metaplasia within the polyp stroma.
  
  
  CONCLUSIONS
  Heterotopic ossification in colonic adenomas is a particularly rare phenomenon, with the majority of cases occurring within malignant lesions. The suggested mechanisms for its aetiology still remain unclear.
authors.affiliation: School of Graduate Medicine and Health, University of Nottingham United Kingdom, Derby, UK. mzyyvaw@nottingham.ac.uk
authors.forename: Victoria
authors.initials: V
authors.lastname: White
authors.forename: Aidan G
authors.initials: AG
authors.lastname: Shaw
authors.forename: Gillian M
authors.initials: GM
authors.lastname: Tierney
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Lund
authors.forename: David
authors.initials: D
authors.lastname: Semeraro