<qa>  What is the morphologically classified as macrovesicular or microvesiSteatosis is assessed according to the pattern and the amount of fatty infiltration in hepatic tissue sections. Traditionally, fatty accumulation has been classified morphologically as macrovesicular or microvesicular. Macrovesicular steatosis is characterized by a single, bulky fat vacuole in the hepatocyte that displaces the nucleus to the edge of the cell. The less conspicuous microvesicular steatosis, usually related to toxins or metabolic disorders, is characterized by accumulation of tiny lipid vesicles in the cytoplasm of hepatocytes without nuclear dislocation. Current quantification and grading of liver steatosis originates from studies performed in the early 1990s, when steatosis was classified as mild, moderate, or severe if, less than 30, 30-60, or more than 60 of hepatocytes, respectively, display fatty infiltrations. 