Fig. 4: Example cases from the test set.

Per case from top to bottom: the most representative whole slide image for that case, the extracted tiles colored based on the attention weights assigned by the AI model, the tile with the largest attention weight at a higher magnification, and the classification result. Classification decisions were obtained using a threshold corresponding to a sensitivity of 0.95 on the in-distribution test set. Images for cases shown in the two leftmost columns were acquired using the ScanScope XT scanner (Aperio) and in the two rightmost columns using the NanoZoomer 2.0-XR scanner (Hamamatsu). a Correct predictions for cases from the low complexity category. From left to right: dermal nevus, compound nevus, dermal nevus, and (acral) junctional nevus. b Correct predictions for cases from the high complexity category. From left to right: superficial spreading melanoma, nodular melanoma, WNT-activated melanocytoma, and Spitz nevus. c Incorrect predictions. From left to right: dermal nevus and squamous cell carcinoma (out-of-distribution), compound nevus and scar tissue, dermal nevus with uncommon morphology (heavily pigmented and likely congenital), and WNT-activated melanocytoma.