title: Pitfalls in the use of whole slide imaging for the diagnosis of central nervous system tumors: A pilot study in surgical neuropathology.
abstract: BACKGROUND
  Whole slide imaging (WSI) finds increasingly higher value in everyday surgical pathology in addition to its well-established use for educational and research purposes. However, its diagnostic utility, especially in subspecialty settings such as neuropathology, is not fully validated. Neuropathology practice is unique with smaller overall tissue size and frequent need for high-power evaluation. In addition, tumor grade is an integral part of the initial diagnosis. The purpose of this study is to assess the feasibility of primary pathology diagnosis of surgical neuropathology specimens using WSI.
  
  
  METHODS
  We reviewed consecutive surgical neuropathology cases diagnosed in our institution during a 2-month period and identified a single diagnostic slide, which was scanned at 40× magnification. Two neuropathologists who were blinded to the original diagnoses reviewed the whole slide image and rendered a diagnosis including tumor grade when applicable. They reviewed the single diagnostic slide after a wash-out period. Intra- and inter-observer discrepancies, as well as reasons for discrepancies, were evaluated.
  
  
  RESULTS
  The concordance rates were 94.9% and 88% for two neuropathologists. Two critical issues leading to discrepancies were identified: (1) identification of mitoses and (2) recognition of nuclear details.
  
  
  CONCLUSIONS
  Given the current study is exclusively for surgical neuropathology cases, an all-encompassing conclusion about the utility of WSI for diagnostic purposes may not be available. Nevertheless, pathologists should be aware of the potential pitfalls due to identification of mitotic figures and nuclear details. We recommend independent validation for each subspecialty of pathology to identify subspecialty-specific concerns, so they can be properly addressed.
authors.affiliation: Department of Pathology, Division of Neuropathology, University of California, San Francisco, CA, USA.
authors.forename: Melike
authors.initials: M
authors.lastname: Pekmezci
authors.affiliation: School of Medicine, Koc University, Istanbul, Turkey.
authors.forename: Sanem Pinar
authors.initials: SP
authors.lastname: Uysal
authors.affiliation: School of Medicine, Koc University, Istanbul, Turkey.
authors.forename: Yelda
authors.initials: Y
authors.lastname: Orhan
authors.affiliation: Department of Pathology, Division of Neuropathology, University of California, San Francisco, CA, USA.
authors.forename: Tarik
authors.initials: T
authors.lastname: Tihan
authors.affiliation: Department of Pathology, Division of Neuropathology, University of California, San Francisco, CA, USA.
authors.forename: Han Sung
authors.initials: HS
authors.lastname: Lee
keywords: Central nervous system tumors; digital pathology; neuropathology; whole slide imaging