The primary objective of this study is to evaluate the safety and accuracy of the Hamamatsu WSI compared to those of the reference method (conventional light microscope (Glass)) under clinical use conditions as an aid for pathologists to view, review and diagnose digital images of surgical pathology slides.

The primary endpoint is the indicator of major discordance in primary diagnosis between ground truth case diagnosis and case diagnosis by each modality, WSI and Glass, separately.

Inclusion Criteria:

• Cases originating from and that were diagnosed at that local site
• Cases are available in the site's archive
• Cases are at least 1 year old since accessioning
• Cases are selected because their primary diagnosis is consistent with the assigned target categories
• Cases have a set of slides representative of the primary diagnosis for which it has been selected

Slide selection for a given case must meet the following criteria:

• Slide is obtained by surgical pathology and prepared from FFPE human tissue
• Slides must be stained with H&E and accompanying special stains (histochemical and/or immunohistochemical)
• All special stains slides (histochemical and/or immunohistochemical) where the slide and stain is used for diagnosis, not prognosis.
• A chosen slide must demonstrate and be representative of the primary diagnosis; 1 slide selection may suffice for biopsy cases,
• For resection cases, a minimum of 5 slides must be selected, which represent the primary diagnosis. If represented with less than 5 slides, additional slides (primary, secondary, or benign slides) from same case may be used to fulfill minimum number
• Slide is intact, has correct size/thickness, good edges, undamaged coverslip, without pen markings that can't be removed, no air bubbles, tidy labels, and fulfills the quality checks per the general clinical practice

Exclusion Criteria:

• Case does not have relevant slides or if case information necessary for the study is missing
• Case is still active (less than 1 year old) at the local site
• Cases for which the control slides for immunohistochemistry and special stains are not available
• Two cases from same individual
• Gross-only cases that have no slides
• Cases that are frozen section, cytology or hematology or immunofluorescence specimens only
• Case where the only available set of slides have evidence only of secondary or no diagnoses and not the primary diagnosis for which the case is being screened.

Slides for a given case will be excluded if they meet the following criterion:

• Glass slide that is broken, has abnormal size/thickness, beveled edges, poor coverslip (cracks, waviness, scratches), is sticky, has many pen markings or dirt that cannot be removed, contains air bubbles and overhanging labels that can't be corrected, and if stain is severely faded.

Because there was no patient involvement in the study and no impact on patient diagnoses, there were no safety endpoints for the study

Because there was no patient involvement in the study and no impact on patient diagnoses, there were no safety endpoints for the study. Therefore no adverse event assessment or monitoring took place.

Adjudicators are blinded to the imaging modality.