title: Transpapillary biliary forceps biopsy to distinguish benign biliary stricture from malignancy: how many tissue samples should be obtained?
abstract: BACKGROUND
  The sensitivity of transpapillary biliary forceps biopsy for malignancy has been reported as varying from 43-81%. Therefore, there are false negatives in more than 20% of patients, which makes it difficult to diagnose benign biliary stricture as benignancy in a clinical setting.
  
  
  METHODS
  To clarify the number of tissue samples that should be obtained during transpapillary forceps biopsy to distinguish benign biliary stricture from malignancy, patients undergoing transpapillary biliary forceps biopsy at our institute were examined retrospectively in this study.
  
  
  RESULTS
  Seventy-two biliary forceps biopsy procedures were performed on 61 patients. The final diagnoses were malignant biliary stricture in 34 patients and benign stricture in 27 patients. The overall sensitivity and specificity for malignancy in this study were 76.5% and 100%, respectively. There were zero out of 10 (0%) false-negative patients when three or more tissue samples were obtained. In contrast, when four or more tissue samples were obtained, eight out of eight (100%) patients had negative diagnoses for malignancy and were finally diagnosed with benignancy.
  
  
  CONCLUSIONS
  We suggest that three or more tissue samples are recommended for the diagnosis of biliary malignant stricture.
authors.affiliation: Department of Gastroenterology, Nagoya University Graduate School of Medicine             Department of Endoscopy, Nagoya University Hospital, Nagoya, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kawashima
authors.forename: Akihiro
authors.initials: A
authors.lastname: Itoh
authors.forename: Eizaburo
authors.initials: E
authors.lastname: Ohno
authors.forename: Hidemi
authors.initials: H
authors.lastname: Goto
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hirooka
mesh_terms: D000328:Adult; D000368:Aged; D001649:Bile Duct Diseases / Q000175:diagnosis* / Q000473:pathology; D001650:Bile Duct Neoplasms / Q000473:pathology*; D001653:Bile Ducts, Intrahepatic; D001707:Biopsy, Needle / Q000379:methods; D018281:Cholangiocarcinoma / Q000473:pathology*; D002760:Cholangiopancreatography, Endoscopic Retrograde; D049448:Cholangiopancreatography, Magnetic Resonance; D019160:Endosonography; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012680:Sensitivity and Specificity