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.Materials and 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.

Whole slide imaging compared with light microscopy for primary diagnosis in surgical neuropathology: a validation study

“…These pitfalls could limit the utility of WSI for accurate diagnosis and grading of tumors in surgical neuropathology. 2 However, in our study, those pitfalls reported by Pekmezci et al were not substantiated. After careful review of digitized slides we found that all discordant cases were attributed to misinterpretation as the image quality was good enough to appreciate the cytological details and to recognize mitotic figures (Figure 1A-D).…”

“…Fallon et al have shown a high correlation between frozen section slides and WSI with 52 ovarian frozen section diagnoses. 2 This accuracy rate maybe similar to neuropathology frozen sections. Several studies concluded that WSI as a diagnostic modality is not inferior to TLM.…”

“…Additionally the one diagnostic slide approach has been used in several studies. [2][3][4] The sixty selected cases covered a broad range of surgical neuropathological entities encountered at our institution. The original surgical pathology numbers were replaced by a study identifier (case number).…”

“…Several studies concluded that WSI as a diagnostic modality is not inferior to TLM. 2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Validation of the digital pathology system is required to ensure laboratory compliance with accrediting organizations such as the Joint Commission and College of American Pathologists (CAP) and to assure the accuracy of diagnosis. Validation studies have shown a high concordance rate between WSI and TLM in different subspecialties of anatomical pathology.…”

Validation of Whole-slide Digitally Imaged Melanocytic Lesions: Does Z-Stack Scanning Improve Diagnostic Accuracy?

“…stated that the major reason for undergrading in brain tumor cases was the inability to recognize mitosis in WSI review. [ 21 ]…”