Fig. 8: A false negative example of metastasis in a patient with preoperative chemotherapy.

This whole-slide image (a) (close-up view: c) with a small focus (2.16 mm in size) of metastatic signet ring cell/poorly differentiated adenocarcinoma (arrowheads) was misclassified as negative. However, class activation mapping (b, d) still highlighted areas with relatively high density of tumor cells.