title: Analysis of false-negative diagnoses on endoscopic brush cytology of biliary and pancreatic duct strictures: the experience at 2 university hospitals.
abstract: BACKGROUND
  Endoscopic brush cytology is a valuable technique for the diagnosis of pancreatobiliary malignancy. Despite its widespread use, the sensitivity of this method has been reported as approximately 50%. The specificity is usually higher than 95%. Few reports have systematically analyzed the reasons for this relatively low sensitivity.
  
  
  OBJECTIVE
  To determine the rate and reasons for false-negative diagnoses in endoscopic brushing cytology of biliary and pancreatic ducts based on the results of sensitivity, specificity, accuracy, and positive and negative predictive values.
  
  
  METHODS
  Retrospective analysis of laboratory data and slide review of false-negative cases.
  
  
  METHODS
  Two tertiary care state university hospitals.
  
  
  METHODS
  A total of 183 pancreatobiliary brushing specimens obtained from patients undergoing endoscopic retrograde cholangiopancreatography for biliary or pancreatic duct disease for a 4- to 5-year period.
  
  
  METHODS
  Endoscopic retrograde cholangiopancreatography brushings.
  
  
  METHODS
  Determination of sensitivity, specificity, accuracy, and positive and negative predictive values. Analysis of false-negative results.
  
  
  RESULTS
  The sensitivity, specificity, accuracy, and positive and negative predictive values, overall, were 48%, 98%, 79%, 92%, and 76%, respectively. Sampling error was a major cause of false-negative diagnoses (67%), followed by interpretive (17%) and technical errors (17%).
  
  
  CONCLUSIONS
  Improvements in sensitivity and diagnostic accuracy for cancer of the pancreatobiliary tract can be achieved by optimizing slide preparatory techniques. Also, enhancement of the cytologist's diagnostic skills enables the identification of the morphologic features of premalignant lesions. Repeat brushings are indicated for suspicious or negative results not consistent with the clinical or radiologic findings.
authors.affiliation: Department of Pathology, University of Texas Medical Branch at Galveston, 77555-0548, USA. Rologron@utmb.edu
authors.forename: R
authors.initials: R
authors.lastname: Logrono
authors.forename: D F
authors.initials: DF
authors.lastname: Kurtycz
authors.forename: C P
authors.initials: CP
authors.lastname: Molina
authors.forename: V A
authors.initials: VA
authors.lastname: Trivedi
authors.forename: J Y
authors.initials: JY
authors.lastname: Wong
authors.forename: K P
authors.initials: KP
authors.lastname: Block
mesh_terms: D001649:Bile Duct Diseases / Q000175:diagnosis*; D017734:Bile Ducts, Extrahepatic / Q000473:pathology*; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods*; D003251:Constriction, Pathologic / Q000473:pathology; D005188:False Negative Reactions; D006785:Hospitals, University; D006801:Humans; D010182:Pancreatic Diseases / Q000175:diagnosis*; D010183:Pancreatic Ducts / Q000473:pathology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity