Liver, Hepatocyte – Increased Mitosis
comment:A high mitotic frequency can be seen during phases of early growth, during physiologic conditions such as pregnancy, or in rodents bearing tumors at other sites. While occasional mitoses can be seen in a normal liver, finding more than one or two mitoses per 10 high-power fields is not typical for adult rodents. In this example, the high frequency of mitosis ( Figure 1 , arrows) is a repair response following hepatocyte loss secondary to treatment with a hepatotoxicant.
recommendation:An increased frequency of mitosis is unusual; it should be documented whenever present and given a qualitative severity grade.
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