title: Endoscopic ultrasound-guided fine needle aspiration of the pancreas. Diagnostic utility and accuracy.
abstract: OBJECTIVE
  Endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB) is regarded as a safe and reliable procedure for diagnosing and staging of pancreatic neoplasms. This study retrospectively evaluated both the diagnostic utility and accuracy of pancreatic EUS-FNABs and potential cytologic pitfalls when using Diff-Quik stain for on-site evaluation.
  
  
  METHODS
  Pancreatic EUS-FNABs performed between 1995 and 1998 were identified from the files of the Department of Pathology. All patients were studied via a linear-array ultrasound endoscope with an FNAB device. Immediate evaluation of the specimen by a pathologist using air-dried slides and Diff-Quik stain was done on all cases. An average of five passes (range, three to nine) were performed. Five cytologic categories were identified: nondiagnostic, benign, atypical, suspicious and malignant. EUS disease staging, histologic correlation and clinical follow-up were reviewed.
  
  
  RESULTS
  Sixty-nine consecutive pancreative FNABs were evaluated in the study period. The patients comprised 38 females and 31 males with a mean age of 65 years (range, 36-83). Histologic correlation was available on 40 patients, and follow-up was available on the remaining 29. The cytologic diagnoses included: 31 malignant, 8 suspicious, 6 atypical, 20 benign and 4 nondiagnostic. Forty-three cases were true positive, 9 were true negative, 2 were false positive, and 11 were false negative. The overall sensitivity was 80% and specificity was 82%.
  
  
  CONCLUSIONS
  The study showed that cytologic evaluation of pancreatic EUS-FNABs has 80% sensitivity and 82% specificity. False negative diagnosis was usually due to sampling error. A nondiagnostic cytologic diagnosis should be rendered in the absence of adequate sampling of a lesion. On-site cytologic evaluation of EUS-FNABs aids in guaranteeing specimen adequacy, and the pathologist should be trained to evaluate Diff-Quik-stained samples.
authors.affiliation: Departments of Pathology and Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan, USA.
authors.forename: Alaa M
authors.initials: AM
authors.lastname: Afify
authors.forename: Basim M
authors.initials: BM
authors.lastname: al-Khafaji
authors.forename: Byungki
authors.initials: B
authors.lastname: Kim
authors.forename: James M
authors.initials: JM
authors.lastname: Scheiman
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle / Q000379:methods*; D002467:Cell Nucleus / Q000473:pathology; D002908:Chronic Disease; D003937:Diagnosis, Differential; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology*; D010182:Pancreatic Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000473:pathology; D010195:Pancreatitis / Q000473:pathology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity