[Validation of Whole Slide Imaging for Primary Diagnosis of Gastrointestinal Pathology]

Whole-slide imaging (WSI) technology enables the primary diagnosis of histopathological slides. This study aimed to determine the diagnostic concordance between pathological interpretations made using WSI and those made using light microscopy (LM). For this study, 5,704 consecutive surgical pathological cases from a community hospital were included. The specimens were digitized at x40 magnification for biopsy and endoscopic resection specimens or at x20 magnification for other specimens and evaluated by 11 pathologists for diagnosis using WSI. Subsequently, the specimens were signed out using LM by 3 pathologists after 2 weeks. Diagnoses using WSI were then compared with the diagnoses made by using LM. Most (96.8%) of the 5,704 specimens were obtained from the gastrointestinal tract (2,441 biopsy specimens from the esophagogastroduodenum [42.7%], 1,678 endoscopic resection specimens from the colorectum [29.4%], 1,349 biopsy specimens from the colorectum [23.6%], 133 resected specimens from the gallbladder [2.3%], 56 endoscopic resection specimens from the stomach [0.9%], 30 resected specimens from the ap- pendix [0.5%], 14 skin biopsy specimens [0.2%], and 3 other specimens [0.1%]). The overall concordance between the diagnoses made using WSI and those made using LM was 95.1%. The major and minor dis- crepancy rates for WSI were 0.1% and 4.8%, respectively. None of the discordant cases had any clinical or prognostic implications. In conclusion, this study revealed that WSI can be used for primary diagnosis of gastrointestinal biopsy and endoscopic resection specimens. To the best of our knowledge, this is one of the studies that clearly proved that diagnosis using WSI is equivalent to diagnosis using LM. [Original].