Successful Validation of Virtual Microscopy for Surgical Pathology but Not Cytopathology: Application of the College of American Pathologists (CAP) Guidelines
By any account, this year’s USCAP meeting was a success for anyone who attended – presenter, attendee and/or vendor. One of the single largest pathology-only meetings with a large international contingent attending and high quality educational content at a low price for attendees. Scientific abstracts submitted months ahead of the meeting for research that likely commences before the other meeting is over or shortly thereafter with poster or podium presentations remain one of the mainstays of the meeting with lively discussion concerning the latest concepts and ideas largely in the fields of surgical pathology, cytopathology and other areas of anatomic pathology largely.
One such body of work was presented by Dr. Michael Arnold and his colleagues from Nationwide Children’s Hospital in Columbus, Ohio looking at the application of the CAP guidelines for validation of virtual microscopy within their patient population (pediatric care). This is one of the first studies I am aware of looking at actual implementation of the CAP guidelines for whole slide validation within a laboratory and one of the largest studies I am aware of looking at pediatric pathology cases.
The authors found that while virtual microscopy was highly concordant for surgical pathology cases, the same could not be said for cytopathology. The authors conclude that whole slide imaging may be used for review of pediatric pathology cases but in their hands is not reliable for pediatric cytopathology case work, suggesting the need for high resolution images and Z-stack focusing.
Many thanks to Dr. Arnold and colleagues for sharing their poster (click here for PDF poster) and full abstract below:
Michael A. Arnold, M.D., Ph.D.1; Emily Chenever, MS, PA(AAPA; ASCPcm)1, Peter B. Baker, M.D.1; Daniel Boue, M.D., Ph.D.1; Bonita Fung, M.D.1; Sue Hammond, M.D.1 Brett W. Hendrickson, M.D.1; Samir B. Kahwash, M.D.1; Christopher R. Pierson, M.D., Ph.D.1; Vinay Prasad, M.D.1; Kathleen K. Nicol, M.D.1; Thomas Barr, BS, MLT (ASCP)2
1Department of Pathology and Laboratory Medicine, Nationwide Children’s Hospital, Columbus, OH; 2Nationwide Children’s Hospital, The Research Institute at Nationwide Children’s Hospital, Columbus, OH
Background: Virtual microscopy is rapidly emerging as a key technology for transforming educational and diagnostic services. Recently, CAP published the first guidelines for validating the diagnostic virtual microscopy. Herein, we report the findings of virtual microscopy validation for surgical pathology and cytopathology specimens at our pediatric institution.
Design: The study set consisted of a combination of randomly selected cases and cases selected to represent complex or less common diagnostic categories. Surgical pathology specimens served as a primary modality (60 cases with 130 specimen parts) and cytopathology as a secondary modality (21 cases with 29 specimen parts). In total, the study included 627 slides. Cases were reviewed by the 9 pathologists who had previously completed clinical evaluation of the glass slides, and in accordance with the CAP guidelines.
Digital slides corresponding to those ordered by the pathologist (special stains and immunohistochemical stains) and ancillary test results were available to the pathologist on request after initial digital slide review.
Results: Based on our previous experience, digital capture of cytospin slides and small biopsies was performed at 40x magnification. The remaining slides were captured at 20x magnification in a single plane. Low cellularity prevented capture of 2 cytology slides, precluding evaluation of one case. Of the surgical pathology cases, the final diagnoses were highly concordant with glass slide diagnoses; major diagnostic discrepancies were seen in 2.3% of specimens, and none altered patient management. Diagnoses for cytology specimens were significantly more discordant, with major discrepancies or inadequate cytologic detail for confident review in nearly 29% of cases.
Conclusion: Our results demonstrate that surgical pathology specimens representing the spectrum of pediatric pathology practice can be adequately reviewed using virtual microscopy. However, review of cytology specimens will require improved resolution, perhaps including image capture of multiple focus planes.
USCAP WSI Poster (PDF)
