The Histologic Cut-off Point for Adjacent and Remote Non-neoplastic Liver Parenchyma of Hepatocellular Carcinoma in Chronic Hepatitis B Patients

BACKGROUND The molecular profile of peritumoral non-neoplastic liver parenchyma (PNLP) has recently been suggested as predictive factor of early and late recurrence of hepatocellular carcinoma (HCC). However, there is no definite cut-off point for tumor-free PNLP in terms of either histological or molecular changes. Therefore, our aim is to determine the numerical cut-off point for separating adjacent PNLP and remote PNLP in histopathologic perspective. METHODS Peritumoral tissues from 20 resected HCC patients were sampled from 0 to 40 mm distance from the tumor border (divided into 5-mm columns). Histopathologic parameters such as necroinflammatory activity, fibrosis, bile ductular reaction, hepatic venulitis, peliosis, and steatosis were compared between each column. RESULTS The morphologic changes just adjacent to the tumor were notably severe and faded with distance. The parenchyma within 10 mm of the tumor showed significantly severe inflammation, fibrosis, peliosis and hepatic venulitis compared with those from farther areas. The histopathologic changes of the parenchyma became stable beyond 20 mm. CONCLUSIONS Results of this study revealed that the parenchyma within 10 mm distance from the tumor, or adjacent PNLP, has histopathologic changes that are directly affected by the tumor, and the parenchyma beyond 20 mm as the remote PNLP without tumor effect.