Perinodular ductular reaction/epithelial cell adhesion molecule loss in small hepatic nodules

Figure 2 Immunohistochemistry and hematoxylin-eosin staining pictures. A surgical sample of HCC ≤ 3 cm (a well-differentiated HCC), with pseudogland-like structure (A1, HE, × 200), and the features of the boundary area of the same nodule (A2, HE, × 200); this area showed diffuse loss of DR/EpCAM (A3, IHC, × 200). HGDN had an increased cell density, more than 1.5 times higher than the surrounding non-tumoral liver, often with an irregular trabecular pattern (2-3 cells thick), and small cell dysplasia (B1, HE, × 400). The cirrhotic, large regenerative nodule (CLRN) showed a mild increase in cell density with a monotonous pattern, without cytologic atypia, although they may have large cell dysplasia (C1, HE, × 400). The features of the boundary area of HGDN (B2, HE, × 200) and CLRN (C2, HE, × 200) with focal fatty change are shown respectively. Active DR/EpCAM was present in a high-grade dysplastic nodule (B3, IHC, × 200) and a CLRN (C3, IHC, × 200). HCC: Hepatocellular carcinoma; HGDN: High-grade dysplastic nodule; CLRN: Cirrhotic, large regenerative nodule; DR: Ductular reaction; EpCAM: Epithelial cell adhesion molecule; IHC: Immunohistochemistry; HE: Hematoxylin-eosin staining.