The Use of Central Pathology Review with Digital Slide Scanning in Advanced-stage Mycosis Fungoides and Sézary Syndrome

This pathology PILOT study aims to define the role and feasibility of centralized pathology review in a cohort of 75 patients from different centers in the United States and Europe using digital slide scanning. The pathologic material from 75 patients who had been diagnosed with mycosis fungoides/Sézary syndrome and were clinically staged as IIb or above was retrieved from 11 participating centers. Each pathology reviewer was provided with the pathologic diagnosis (by the referring pathologist), and the following list of histopathologic criteria (presence or absence) from the initial report: Epidermotropism, folliculotropism (FT), large cell transformation, syringotropism, and granulomas. Patients with advance stage were selected for this study as this is a population where there is significant variability in the diagnosis of pathologic prognostic and predictive biomarkers. The slides were digitally scanned with an Aperio scanner and consensus review of cases occurred when major or minor discrepancies between the referral diagnosis and central pathology review occurred. Among the 75 cases, 70 (93.3%) had a final consensus diagnosis between the 3 central review pathologists. The overall agreement between the consensus review and the referring pathologist was 60%. The overall agreement was also higher between the reviewers and consensus review, compared with the referring pathologist and consensus. 65.3% of cases had some type of discrepancy (major or minor) between the outside and consensus review. Major discrepancies were seen in 34 of 73 cases (46.6%; 73 cases indicated a yes or no response). Minor discrepancies were seen in 32 of 75 (42.7%) of cases. Most of the major discrepancies were accounted by a difference in interpretation in the presence or absence of large cell transformation or FT. Most minor discrepancies were explained by a different interpretation in the expression of CD30. We found digital slide scanning to be a beneficial, reliable, and practical for a methodical approach to perform central pathology review in the context of a large clinical prospective study.