title: Interobserver agreement among cytopathologists in the evaluation of pancreatic endoscopic ultrasound-guided fine needle aspiration cytology specimens.
abstract: OBJECTIVE
  Endoscopic ultrasound with fine needle aspiration (EUS-FNA) has become the standard of care in the evaluation of solid pancreatic lesions. Limited data exist on interobserver agreement (IOA) among cytopathologists in assessing solid pancreatic EUS-FNA specimens. This study aimed to evaluate IOA among cytopathologists in assessing EUS-FNA cytology specimens of solid pancreatic lesions using a novel standardized scoring system and to assess individual clinical and cytologic predictors of IOA.
  
  
  METHODS
  Consecutive patients who underwent EUS-FNA of solid pancreatic lesions at a tertiary care referral center were included. EUS-FNA slides were evaluated by four blinded cytopathologists using a standardized scoring system that assessed final cytologic diagnosis and quantitative (number of nucleated/diagnostic cells) and qualitative (bloodiness, inflammation/necrosis, contamination, artifact) cytologic parameters. Final clinical diagnosis was based on final cytology, surgical pathology, or 1-year clinical follow-up. IOA was calculated using multi-rater kappa (κ) statistics. Bivariate analyses were performed comparing cases with and without uniform agreement among the cytopathologists followed by logistic regression with backward elimination to model likelihood of uniform agreement.
  
  
  RESULTS
  Ninety-nine patients were included (49 % males, mean age 64 years, mean lesion size 26 mm). IOA for final diagnosis was moderate (κ = 0.45, 95 % confidence interval (CI) 0.4 - 0.49) with minimal improvement when combining suspicious and malignant diagnoses (κ = 0.54, 95 %CI 0.49 - 0.6). The weighted kappa value for overall diagnosis was 0.65 (95 %CI 0.54 - 0.76). IOA was slight to fair (κ = 0.04 - 0.32) for individual cytologic parameters. A final clinical diagnosis of malignancy was the most significant predictor of agreement [OR 3.99 (CI 1.52 - 10.49)].
  
  
  CONCLUSIONS
  Interobserver agreement among cytopathologists for pancreatic EUS-FNA specimens is moderate-substantial for the final cytologic diagnosis. The final clinical diagnosis of malignancy was the strongest predictor of agreement. These results have significant implications for patient management and need to be validated in future trials.
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Rawad
authors.initials: R
authors.lastname: Mounzer
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Roy
authors.initials: R
authors.lastname: Yen
authors.affiliation: Department of Pathology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Carrie
authors.initials: C
authors.lastname: Marshall
authors.affiliation: Department of Pathology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Sams
authors.affiliation: Department of Pathology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Sanjana
authors.initials: S
authors.lastname: Mehrotra
authors.affiliation: Department of Pathology, Denver Health Medical Center, Denver, CO, USA.
authors.forename: Mohamed Sherif
authors.initials: MS
authors.lastname: Said
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Joshua C
authors.initials: JC
authors.lastname: Obuch
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Brauer
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Augustin
authors.initials: A
authors.lastname: Attwell
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Norio
authors.initials: N
authors.lastname: Fukami
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Raj
authors.initials: R
authors.lastname: Shah
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Stuart
authors.initials: S
authors.lastname: Amateau
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Hall
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Hosford
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Wilson
authors.affiliation: Division of Gastroenterology, University of Kansas School of Medicine and Veterans Affairs Medical Center, Kansas City, MO, USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Rastogi
authors.affiliation: Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
authors.forename: Sachin
authors.initials: S
authors.lastname: Wani