title: Endoscopic transpapillary bile duct biopsy with the combination of intraductal ultrasonography in the diagnosis of biliary strictures.
abstract: BACKGROUND
  When endoscopic retrograde cholangiopancreatography (ERCP) guided bile duct biopsy fails to demonstrate malignancy, it remains unclear how to manage patients with presumably malignant strictures.
  
  
  OBJECTIVE
  To evaluate the value of intraductal ultrasonography (IDUS) when bile duct biopsy is negative.
  
  
  METHODS
  Sixty two patients with strictures of the bile duct were studied prospectively. During ERCP, IDUS was performed using an ultrasonic probe (diameter 2.0 mm; frequency 20 MHz). Following IDUS, a bile duct biopsy was performed using forceps (diameter 1.8 mm). The IDUS images of the tumour were classified as polypoid lesions, localised wall thickening, intraductal sessile tumours, sessile tumour outside of the bile duct, or absence of apparent lesion. The bile duct wall structures at the site of the tumour as well as the maximum diameter of the tumour were also analysed. The IDUS findings were compared with the histological findings or clinical course.
  
  
  RESULTS
  When the IDUS images showed a polypoid lesion (n=19), localised wall thickening (n=8), intraductal sessile tumour (n=13), and sessile tumour outside of the bile duct (n = 20), the sensitivities of the biopsy were 80%, 50%, 92%, and 53%, respectively. Multiple regression analysis showed that the presence of sessile tumour (intraductal or outside of the bile duct: p<0.05), tumour size greater than 10.0 mm (p<0.001), and interrupted wall structure (p<0.05) were independent variables that predicted malignancy.
  
  
  CONCLUSIONS
  When biopsy fails to demonstrate evidence of malignancy, the presence of sessile tumour (intraductal or outside of the bile duct), tumour size greater than 10.0 mm, and interrupted wall structure on IDUS images are factors that can predict malignancy.
authors.affiliation: Department of Gastroenterology, Jichi Medical School, Yakushiji, Tochigi 329-0498, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tamada
authors.forename: T
authors.initials: T
authors.lastname: Tomiyama
authors.forename: S
authors.initials: S
authors.lastname: Wada
authors.forename: A
authors.initials: A
authors.lastname: Ohashi
authors.forename: Y
authors.initials: Y
authors.lastname: Satoh
authors.forename: K
authors.initials: K
authors.lastname: Ido
authors.forename: K
authors.initials: K
authors.lastname: Sugano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D001706:Biopsy / Q000379:methods; D002760:Cholangiopancreatography, Endoscopic Retrograde; D002779:Cholestasis / Q000209:etiology*; D019160:Endosonography / Q000379:methods*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D012680:Sensitivity and Specificity