CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
Editors: Liron Pantanowitz, MD, director of anatomical pathology, Department of Pathology, University of Michigan, Ann Arbor, and David McClintock, MD, associate chief medical information officer for pathology, Department of Pathology, University of Michigan.
Use of WSI versus light microscopy for primary diagnosis in surgical pathology
January 2021—A major barrier to adopting whole slide imaging for primary diagnosis in the United States was FDA regulatory approval. However, the FDA approved marketing of the first whole slide imaging (WSI) system for digital pathology in 2017. The agency subsequently cleared Leica’s Aperio AT2 DX system for in vitro diagnostic use to aid pathologists in reviewing and interpreting digital images of surgical pathology slides prepared from formalin-fixed paraffin-embedded tissue. The authors conducted a study in which they compared pathologists’ primary diagnoses rendered through the use of WSI versus standard glass microscopy. Their multicenter, double-blind, randomized clinical trial was conducted at five sites: the University of California Davis, Pacific Rim Pathology, Dignity Health, TriCore Reference Laboratories, and Intermountain Healthcare. The investigators included in the study 2,045 cases comprising 5,849 slides. Their dataset was enriched to include more difficult diagnostic categories. Trained laboratory technicians cleaned the glass slides and scanned them using an Aperio AT2 DX system at 20× magnification (0.75 numerical aperture). A team of 19 reading pathologists made the diagnoses. Pathologists reviewed cases using glass slides and WSI via workstations with Dell medical-grade monitors and ImageScope slide-viewing software in randomized order. There was a minimum 31-day washout period between modality reads. The overall majority discrepancy rates—that is, disagreement between the diagnoses of the reading pathologist and original sign-out pathologist—were 3.2 percent for glass slides and 3.64 percent for WSI, a difference of 0.44 percent. Therefore, the authors concluded that whole slide images acquired using the Aperio system and viewed on Dell monitors with ImageScope software were non-inferior to traditional glass slides examined on a standard light microscope for primary diagnosis in anatomic pathology. As the barriers to using a WSI system for primary diagnosis diminish, it should be easier for labs to transition to a fully digital approach.
Borowsky AD, Glassy EF, Wallace WD, et al. Digital whole slide imaging compared with light microscopy for primary diagnosis in surgical pathology. Arch Pathol Lab Med. 2020;144(10):1245–1253.
Correspondence: Dr. Alexander D. Borowsky at adborowsky@ucdavis.edu
Remote anatomic pathology medical student education during the pandemic
The COVID-19 pandemic has changed institutional approaches to medical student education, with many medical schools and clinical clerkships turning to remote learning after halting in-person education. At the University of Washington School of Medicine, pathology educators used the pandemic as an opportunity to create a two-week-long remote-learning course in anatomic pathology to reach a broader audience of medical students than would typically be exposed to this type of training. The educators described their two-week-long curriculum for anatomic pathology, which encompassed lectures, virtual slides, discussion groups, and unique case-based activities. The course objectives were to provide organ-based modules to reinforce pathology concepts, educate clinical students about the terminology and workflow of pathology, and increase interest in pathology as a career path. The educators used such digital tools as Zoom, Microsoft PowerPoint and Teams, PathPresenter, and Canvas to deliver content and engage students virtually. They analyzed the reach and effectiveness of their course by reviewing prior and current enrollment in anatomic pathology rotations and administering pre- and post-course surveys. Initial enrollment numbers showed an almost 10-fold increase in medical students per month participating in a pathology rotation. Thirteen percent of clinical students (70 of 540 clinical third- and fourth-year students) selected the course over 12 other virtual courses. Overall, the students rated the course highly (average, 4.5 on a five-point scale) and provided many positive written comments. Furthermore, a comparison of surveys before and after the course showed that medical students’ comfort with anatomic pathology subject matter and skills had doubled. Notably, two medical students immediately applied for a postsophomore pathology fellowship following the course. The authors concluded that the pandemic provides an opportunity to rethink medical students’ pathology experiences and use technology such as screen annotation, Web cameras, and virtual slide presentations to reach students remotely. They intend to collaborate with laboratory medicine colleagues to develop a comprehensive four-week anatomic pathology rotation. They also plan to maintain the virtual format post-pandemic to address nonpandemic–related obstacles to students participating in on-site pathology training, such as family obligations, health issues, or financial limitations.