The electron microscope has added a new set of dimension to study of the pathology of various kinds of liver diseases. From these observations a new pathology has been emerging, organelle pathology, in which the altered structure as well as the altered function of the liver is being explained as a result of injury to specific part of the hepatocytes. Despite the emergence of this new system of pathology, little has been gleaned to which diagnostic usefulness can be ascribed.
The present study consists of detailed ultrastructural study of human hepatocellular carcinoma (6 cases), fatty liver (5 cases), and hepatitis (3 cases).
In the malignant hepatocyte, nucleus showed irregular shape, inclusion body and increased in size of nucleus and nucleolus. The mitochondria showed great variety in size and shape with swelling and paucity of cristae, and ribosome of rough endoplasmic reticulum was somewhat reduced and disarrayed. There was no close relationship between clinical features or differentiation of the hepatocyte and ultrastructural changes.
The fatty liver cell contained large or aggregated small lipid particle in cytoplasm, but it was unable to explain the connection between the accumulation of lipid particle and the organellar changes. There was no relationship between clinical features or the degree of fat deposition in hepatocyte and ultrastructural changes.
In hepatitis, cytoplasmic vacuole or saccule contained round, virus-like dense particle with a diameter of 300 to 500 angstrom. Endoplasmic reticulum was somewhat swollen. The electron microscopic study in one patient of hepatitis without clear evidence of typical changes by light microscopic findings was helpful for confirming diagnosis of viral hepatitis.