Fig. 3

Heterogeneous expression pattern of SMARCA2 and PD-L1 in dedifferentiated carcinoma (case 15). Prominent adenocarcinoma components and undifferentiated components were observed in case 15 (D, arrows, ×40). The adenocarcinoma components showed a prominent glandular cavity (A, × 200), and the undifferentiated components showed neoplastic cells loosely arranged in a patchy pattern, a moderate amount of pale eosinophilic cytoplasm with a large nucleus; focal cytoplasm showed clear (G, ×200). In the adenocarcinoma components, SMARCA2 was intact (B, × 200), and PD-L1 was negative (C, × 200); while in the undifferentiated components, SMARCA2 showed complete loss (H, × 200), and PD-L1 showed diffused moderate positive expression (I, × 200)