PCNA labeling index of ductular reaction (PI- DR) positively correlated with the necroinflammation grade and fibrosis stage. (A) The K7 immunostaining ductular reaction seen with examples in peritumoral tissue of hepatocellular carcinoma (sacle bar = 100 μm). Increased numbers of ductular reactions (≥50%) are noted at the edge of the portal tract containing a lymphoid aggregate (left), whereas continuous ductular reactions (<50%) are present along the edge of an enlarged portal tract (right). (B) Light micrograph of area displaying PCNA staining for DR represents a low level of proliferation activity (upper right) and a high level of proliferation activity (lower right), as corresponding with serious K7 staining of DR (sacle bar = 100 μm). (C) A split scattergram with fitting line shows peritumoral PI-DR correlates with necroinflammation grade in peritumoral tissue. (D) The peritumoral PI-DR is significantly correlated with fibrosis stage. Spearman correlation analysis provides correlation coefficient (r) and P-value.