Wei B-RHalsey CHHoover SBPuri MYang HHGallas BDLee MPChen WDurham ACDwyer JESánchez MDTraslavina RPFrank CBradley CMcGill LDEsplin DGSchaffer PACramer SDLyle LTBeck JBuza EGong QHewitt SMSimpson RM2026-01-152022-03-28Wei BR, Halsey CH, Hoover SB, Puri M, Yang HH, Gallas BD, Lee MP, Chen W, Durham AC, Dwyer JE, Sánchez MD, Traslavina RP, Frank C, Bradley C, McGill LD, Esplin DG, Schaffer PA, Cramer SD, Lyle LT, Beck J, Buza E, Gong Q, Hewitt SM, Simpson RM. (2019). Agreement in Histological Assessment of Mitotic Activity Between Microscopy and Digital Whole Slide Images Informs Conversion for Clinical Diagnosis. Academic Pathology. 6.https://mro.massey.ac.nz/handle/10179/74031Validating digital pathology as substitute for conventional microscopy in diagnosis remains a priority to assure effectiveness. Intermodality concordance studies typically focus on achieving the same diagnosis by digital display of whole slide images and conventional microscopy. Assessment of discrete histological features in whole slide images, such as mitotic figures, has not been thoroughly evaluated in diagnostic practice. To further gauge the interchangeability of conventional microscopy with digital display for primary diagnosis, 12 pathologists examined 113 canine naturally occurring mucosal melanomas exhibiting a wide range of mitotic activity. Design reflected diverse diagnostic settings and investigated independent location, interpretation, and enumeration of mitotic figures. Intermodality agreement was assessed employing conventional microscopy (CM40×), and whole slide image specimens scanned at 20× (WSI20×) and at 40× (WSI40×) objective magnifications. An aggregate 1647 mitotic figure count observations were available from conventional microscopy and whole slide images for comparison. The intraobserver concordance rate of paired observations was 0.785 to 0.801; interobserver rate was 0.784 to 0.794. Correlation coefficients between the 2 digital modes, and as compared to conventional microscopy, were similar and suggest noninferiority among modalities, including whole slide image acquired at lower 20× resolution. As mitotic figure counts serve for prognostic grading of several tumor types, including melanoma, 6 of 8 pathologists retrospectively predicted survival prognosis using whole slide images, compared to 9 of 10 by conventional microscopy, a first evaluation of whole slide image for mitotic figure prognostic grading. This study demonstrated agreement of replicate reads obtained across conventional microscopy and whole slide images. Hence, quantifying mitotic figures served as surrogate histological feature with which to further credential the interchangeability of whole slide images for primary diagnosis.CC BY-NC-ND 4.0(c) 2019 The Author/shttps://creativecommons.org/licenses/by-nc-nd/4.0/cancer gradinginformaticsprognosisreproducibility studyvalidationdigital pathologytechnology adoptiontrainingJournal article10.1177/23742895198598412374-2895journal-article2374289519859841S2374289521001561