title: Capsule endoscopy to detect primary tumour site in metastatic neuroendocrine tumours.
abstract: BACKGROUND
  In patients with metastatic neuroendocrine tumours, primary tumour localisation is often difficult with morphological and/or functional imaging. Although utilised in investigating various small bowel pathologies, evidence for using video capsule endoscopy to identify suspected small bowel primaries in patients exhibiting metastatic neuroendocrine tumours is limited.
  
  
  OBJECTIVE
  To assess the role of video capsule endoscopy in locating primary small bowel neuroendocrine tumours when conventional imaging fails to identify the origin of metastatic disease.
  
  
  METHODS
  We retrospectively compared our institutional database of patients presenting with metastatic neuroendocrine tumours between January 2010 and December 2013 with an analogous database of patients undergoing video capsule endoscopy for various indications. Patients whose primary tumours were not located radiologically and also underwent capsule endoscopy were identified.
  
  
  RESULTS
  390 patients with metastasised neuroendocrine tumours presented within the study period. In 11 (2.8%) the primary tumour was not located radiologically. Video capsule endoscopy identified lesions suggestive of small bowel primary in 8/10 patients in whom it was successful. Small bowel primary was confirmed by histological analysis of surgical specimens.
  
  
  CONCLUSIONS
  Our study supports the use of video capsule endoscopy as part of the diagnostic work-up in selected patients presenting with metastatic neuroendocrine tumours of unknown primary. The clinical utility of this technology requires clearer definition.
authors.affiliation: Department of Surgery and Cancer, Imperial College London, Hammersmith Campus, London, United Kingdom. Electronic address: a.frilling@imperial.ac.uk.
authors.forename: Andrea
authors.initials: A
authors.lastname: Frilling
authors.affiliation: Department of Gastroenterology, Imperial College London, Hammersmith Campus, London, United Kingdom.
authors.forename: Geoff
authors.initials: G
authors.lastname: Smith
authors.affiliation: School of Medicine, Imperial College London, Hammersmith Campus, London, United Kingdom.
authors.forename: Ashley Kieran
authors.initials: AK
authors.lastname: Clift
authors.affiliation: Department of Gastroenterology, Imperial College London, Hammersmith Campus, London, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Martin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D053704:Capsule Endoscopy / Q000379:methods*; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007414:Intestinal Neoplasms / Q000175:diagnosis / Q000556:secondary*; D007421:Intestine, Small / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis / Q000473:pathology*; D018358:Neuroendocrine Tumors / Q000175:diagnosis / Q000556:secondary*; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors; D006113:United Kingdom
keywords: Neoplasm; Neuroendocrine tumour; Small bowel; Unknown primary; Video capsule endoscopy