Scanning electron microscopy of chronic hepatitis C. An OsO4 maceration study on human biopsies.

A study at the scanning electron microscope (SEM) on the liver changes in chronic hepatitis C was carried out in human needle biopsies from four patients. Intracellular structures were visualized by a novel modification of the OsO4 maceration method that allows to investigate human pathological specimens. At low magnification we observed both sinusoidal and hepatic cells alterations: sinusoids appeared occluded by lymphocytes, hypertrophic Kupffer cells, activated perisinusoidal cells, necrotic material and apoptotic bodies. Some hepatocytes showed ballooning, arrangement in rosettes, and structural changes related to apoptosis: cell rounding, detachment from neighbouring cells, clustering of cytoplasmic organelles and cell fragmentation. We also found periterminal, sinusoidal, and pericellular severe fibrosis, and bile duct damage of moderate degree. At higher magnification, after removing the intracellular matrix, all the intracellular structures appeared normal, except for focal dilatation of smooth endoplasmic reticulum. Our findings clearly demonstrate the usefulness of the OsO4 maceration method for the study of chronic hepatitis and of liver disease in general. Thank to this technique, in fact, SEM becomes a diagnostic tool complementary to light microscopy and transmission electron microscopy (TEM), for its unique ability to give both low magnification panoramic views and detailed high magnification 3D images of cell organelles.