title: Variation of cytopathologists' use of the indeterminate diagnostic categories "atypical" and "suspicious for malignancy" in the cytologic diagnosis of solid pancreatic lesions on endoscopic ultrasound-guided fine-needle aspirates.
abstract: Indeterminate cytologic diagnoses in endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNA) of solid pancreatic lesions include the diagnostic categories "atypical" (ATY) and "suspicious for malignancy" (SUSP), which are used at variable rates and are associated with variable underlying risk of malignancy. The aim of this study was to determine individual cytopathologists' rates of indeterminate diagnoses in EUS-FNA of solid pancreatic lesions and their relationship to cytopathologists' experience and volume of pancreatic EUS-FNA examined, as well as the potential impact of departmental consensus review on indeterminate diagnoses.
  
  
  METHODS
  The diagnostic rates of ATY and SUSP and their underlying risk of malignancy were calculated for six cytopathologists who diagnosed 1,114 of 1,225 EUS-FNA of solid pancreatic lesions from 1/1/2001 to 9/15/2014, and were then compared for the periods before and after the implementation of departmental consensus review during 2009.
  
  
  RESULTS
  The six cytopathologists diagnosed 10% of cases as indeterminate; 82 (7.4%) as "atypical" and 29 (2.6%) as "suspicious". The individual cytopathologists' indeterminate diagnosis rates varied twofold (6.67-12.80%) and did not correlate with their experience, total or annual volume of EUS-FNAs. Of the 56/99 (56.57%) cases with follow-up, the underlying rate of malignancy was 47% (35/75; for "atypical" and 87.5% (21/24); for "suspicious"). The underlying rates of malignancy were 33-67% for "atypical" and 80-100% for "suspicious" diagnoses made by individual cytopathologists. The rate of indeterminate diagnoses decreased from 11.55 to 7.88% after the implementation of departmental consensus review.
  
  
  CONCLUSIONS
  Individual cytopathologists' rates of indeterminate diagnoses and their significance vary; however, consensus review is helpful in reducing these rates. Diagn. Cytopathol. 2017;45:3-13. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, Illinois.
authors.forename: Renu K
authors.initials: RK
authors.lastname: Virk
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, Illinois.
authors.forename: Roberto
authors.initials: R
authors.lastname: Gamez
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, Illinois.
authors.forename: Swati
authors.initials: S
authors.lastname: Mehrotra
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, Illinois.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Atieh
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, Illinois.
authors.forename: Güliz A
authors.initials: GA
authors.lastname: Barkan
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, Illinois.
authors.forename: Eva M
authors.initials: EM
authors.lastname: Wojcik
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, Illinois.
authors.forename: Stefan E
authors.initials: SE
authors.lastname: Pambuccian
mesh_terms: D003937:Diagnosis, Differential; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000592:standards*; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D015588:Observer Variation; D010190:Pancreatic Neoplasms / Q000473:pathology*; D009626:Terminology as Topic
keywords: atypical; endoscopic ultrasound-guided fine needle aspiration; indeterminate; pancreas; suspicious; variation