Grade 0: Normal findings Grade 1: Single hepatocytes with small cytoplasmic granules, slightly enlarged and with normal nuclei, mild dilatation of blood vessels Grade 2: >50% hepatocytes with mild vacuolization of cytoplasm and nucleoplasm, strong vasodilation with erythrocytes accumulation, associated with hyperemia and edema Grade 3: All hepatocytes with mild vacuolization of cytoplasm and nucleoplasm and pycnotic nuclei, transmural rupture of small number i.e. up to 50% of blood vessels and perivacsular accumulation of polymorphonuclear cells Grade 4: Pronounced plasmalysis and caryolysis, massive hemorrhagic foci and perivacsular accumulation of polymorphonuclear cells infiltration Grade 5: Necrosis hepatis, diffused hemorrhagic and perivacsular accumulation of polymorphonuclear cells infiltration of hepatic tissue