A Systematic Analysis of Discordant Diagnoses in Digital Pathology Compared With Light Microscopy

Abstract

Context.-Relatively little is known about the significance and potential impact of glass-digital discordances, and this is likely to be of importance when considering digital pathology adoption.Objective.-To apply evidence-based medicine to collect and analyze reported instances of glass-digital discordance from the whole slide imaging validation literature.Design.-We used our prior systematic review protocol to identify studies assessing the concordance of light microscopy and whole slide imaging between 1999 and 2015. Data were extracted and analyzed by a team of histopathologists to classify the type, significance, and potential root cause of discordances.Results.-Twenty-three studies were included, yielding 8069 instances of a glass diagnosis being compared with a digital diagnosis. From these 8069 comparisons, 335 instances of discordance (4%) were reported, in which glass was the preferred diagnostic medium in 286 (85%), and digital in 44 (13%), with no consensus in 5 (2%). Twenty-eight discordances had the potential to cause moderate/severe patient harm. Of these, glass was the preferred diagnostic medium for 26 (93%). Of the 335 discordances, 109 (32%) involved the diagnosis or grading of dysplasia. For these cases, glass was the preferred diagnostic medium in 101 cases (93%), suggesting that diagnosis and grading of dysplasia may be a potential pitfall of digital diagnosis. In 32 of 335 cases (10%), discordance on digital was attributed to the inability to find a small diagnostic/prognostic object.Conclusions.-Systematic analysis of concordance studies reveals specific areas that may be problematic on whole slide imaging. It is important that pathologists are aware of these areas to ensure patient safety.

Validation of a whole‐slide image‐based teleconsultation network

“…Moreover, reanalysis of the discordances showed that only two (minor and major) discrepancies could be attributed to the use of digital pathology (2%), while the other eight discrepancies were due most probably to differences in awareness and interpretation by the individual pathologists. This high overall concordance rate is within the range of previously observed inter‐ and intraobserver variability in digital and microscopic pathology in general, and is in line with previous single‐institute studies by our group and others …”

“…This high overall concordance rate is within the range of previously observed inter-and intraobserver variability in digital and microscopic pathology in general, and is in line with previous single-institute studies by our group 7-10 and others. 11,12 Although there have been many studies validating digital diagnostics, only a few studies validate remote diagnostics specifically. Furness et al evaluated the adequacy of WSI as a medium for internet-based telepathology in the context of the National Renal Pathology External Quality Assurance scheme in the United Kingdom.…”

Being fully digital: perspective of a Dutch academic pathology laboratory

“…Of the 45 pathology laboratories in The Netherlands, 16 own a digital slide scanner, including the eight academic pathology laboratories, and many more have serious plans to buy hardware. However, the adoption of digital pathology for primary diagnostics has remained relatively low, despite widespread validation of digital pathology for primary diagnostics …”

“…However, the adoption of digital pathology for primary diagnostics has remained relatively low, despite widespread validation of digital pathology for primary diagnostics. 12,13 The University Medical Centre (UMC) Utrecht committed 10 years ago to building up a digital pathology infrastructure based on three Aperio scanners (Leica Biosystems, Wetzlar, Germany), a tape storage system, and custom in-house-developed image integration software, amassing a complete digital archive of scanned histology slides over the last 10 years. 1 As of the end of 2015, the total amount of digital slides scanned and archived in the UMC Utrecht digital slide archive (including slides scanned for research) was in the order of 500 terabytes, with >1 200 000 million scanned slides being archived.…”

Digital pathology for primary diagnosis of screen‐detected breast lesions – experimental data, validation and experience from four centres

“…A systematic analysis of instances of diagnostic discordance in glass–digital comparisons of the same histology cases found 335 instances of diagnostic discordance out of 8069 documented instances of a glass diagnosis being compared with a digital diagnosis (4%) 10 . The majority of these discordances would have had no clinical significance, and reflected diagnostic scenarios prone to intra‐ and interobserver variation in diagnosis, regardless of the diagnostic medium used.…”