title: Interobserver agreement in the cytologic grading of atypia in neoplastic pancreatic mucinous cysts with the 2-tiered approach.
abstract: BACKGROUND
  The accurate cytologic grading of epithelial atypia in fine-needle aspirates of pancreatic mucinous cysts has important implications for clinical management. The Papanicolaou Society of Cytopathology has recommended a 2-tiered system of low-grade (LG) and high-grade (HG) for grading this atypia. Using this approach, this study examined the interobserver agreement within a group of cytopathologists at the Cleveland Clinic.
  
  
  METHODS
  Twenty cases of fine-needle aspiration of pancreatic neoplastic mucinous cysts with documented histologic follow-up and representative lesional cells were selected. Blinded to the histologic outcome, 4 cytopathologists were independently asked to assign the highest grade of atypia with the 2-tiered system of LG and HG atypia for these cases. The interobserver agreement was calculated with the κ statistic.
  
  
  RESULTS
  The overall raw agreement in the grading of atypia was 60%. The overall chance-adjusted agreement was fair (κ = 0.28). On the basis of the histologic outcomes, the cases were stratified into group A (HG dysplasia or worse) and group B (LG or intermediate-grade [IG] dysplasia on follow-up). Group A (n = 12) showed good chance-adjusted agreement (κ = 0.65). For group B, the chance-adjusted agreement among the observers was poor (κ = 0.03).
  
  
  CONCLUSIONS
  This study shows that the cytologic recognition of HG dysplasia or worse as HG atypia in pancreatic mucinous cysts has a good degree of interobserver reproducibility among cytopathologists. In contrast, a problematic area with a lack of agreement appears to be the cytologic recognition of LG and IG dysplasia as LG atypia. Additional studies with the development of reproducible criteria and educational tools may help with this challenging distinction. Cancer Cytopathol 2016;124:909-916. © 2016 American Cancer Society.
authors.affiliation: Department of Pathology and Laboratory Medicine, NewYork-Presbyterian Hospital/Weill Cornell Medicine, New York, New York.
authors.forename: Abha
authors.initials: A
authors.lastname: Goyal
authors.affiliation: Department of Pathology, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Fadi W
authors.initials: FW
authors.lastname: Abdul-Karim
authors.affiliation: Department of Pathology, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.affiliation: Department of Pathology, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Jinesh B
authors.initials: JB
authors.lastname: Patel
authors.affiliation: Department of Pathology, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Brainard
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000473:pathology*; D044963:Biopsy, Fine-Needle; D006801:Humans; D060787:Neoplasm Grading; D015588:Observer Variation; D010181:Pancreatic Cyst / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000473:pathology*; D011379:Prognosis; D015203:Reproducibility of Results
keywords: Papanicolaou Society guidelines; atypia; cyst; endoscopic ultrasound; fine-needle aspiration; grading; interobserver; mucinous; pancreas