Figure 3.

Representative slides for estimation of the residual tumor using hematoxylin and eosin staining in the ICI cohort. (A) Example of major pathological response (MPR) in one patient. Islets of residual viable tumor tissue are surrounded by a major inflammatory cellular infiltrate. White rectangle is magnified in (B) and shows a residual tumor islet with large atypical cells (white asterisk) surrounded by small mononucleated inflammatory cells. (C) Example of complete pathological response (pCR) in one patient, with zones of tissue fibrosis and inflammatory infiltrates (delineated in black) and large areas of tumor necrosis with no residual viable tumor. White rectangle is magnified in (D) and shows the demarcation between fibrotic, inflammatory tissue, and necrosis with cholesterol crystal imprints (arrow).