Three-dimensional observations on the alterations of lobular architecture in chronic hepatitis with special reference to its angioarchitecture for a better understanding of the formal pathogenesis of liver cirrhosis

For a better understanding of the formal pathogenesis of liver cirrhosis, the angioarchitecture of the liver lobule in chronic viral hepatitis was investigated three dimensionally. The histological reconstruction method, using serial histological sections, was adopted for the three-dimensional observation. Histology of the case showed chronic active hepatitis with occasional fibrous bridging of the portal to portal tract or hepatic vein. Graphic reconstructions revealed various degrees of altered angioarchitecture from place to place. While the conducting portion of the portal vein was almost preserved, the pathological changes mostly began at the parenchymal portion, especially second step or subsequent branches of the portal vein. In general, portal vein branches showed damage such as stenoses, disappearance, an increase and decrease in number and distorted spatial arrangements. Even in less damaged portal tracts, portal veins showed such changes to some extent. In severely damaged places with bridging fibrosis, a normal lobular angioarchitecture was completely lost; instead, portal veins, arteries and hepatic veins were tangled with each other. Parenchymal nutrition was suggested to be dependent on the remaining third-step portal branches or newly formed ones. However, the hepatic vein system had a tendency to be preserved and distributed fluently in the parenchyma. The distortion of these portal vessels indicated various degrees of loss of the lobular architecture. In conclusion, it is suggested that an early histological sign of cirrhosis develops in the course of chronic hepatitis.