Digital slide images for primary diagnostics in breast pathology: a feasibility study

Digital slide images have been used in many areas of pathology such as teaching, research, digital archiving, teleconsultation, and quality assurance testing. However, they have not much been used as yet for upfront diagnostics. The aim of this study was therefore to test the feasibility of digital slide image-based diagnosis of breast specimens. Sections of 100 breast specimens previously diagnosed conventionally were scanned and rediagnosed on digital slide images by the same pathologists who performed the initial light microscopy-based diagnosis. The digital slide image diagnoses were compared with the light microscopy diagnoses and classified as concordant, slightly discrepant (without clinical or prognostic consequences), or discrepant. The original light microscopy- and digital slide image-based diagnoses were concordant in 93% and slightly discrepant in 6% of cases. There was only 1 discrepant case with clinical or prognostic implication to the patient. However, for this case, no final agreement could be achieved. For 4 of the 6 slightly discrepant cases, digital slide image diagnosis was considered the better one, whereas the original diagnosis was preferred in only 1 case. In addition, for 1 case categorized as slightly discrepant, both the digital slide image and conventional diagnosis were imperfect according to 2 reviewing breast pathologists. This study demonstrates that upfront histopathologic diagnosis of breast biopsies and resections can reliably be done on digital slide image.