Though karyomegaly is predominantly a nuclear change, Figure 1 and Figure 2 (arrow) show enlargement of both hepatocyte cytoplasm and nuclei.
The change is throughout the hepatic lobule but is more prominent in the centrilobular areas.
Karyomegaly is characterized by epithelial cells that contain large, intensely basophilic staining nuclei that are often indented.
It is generally seen as a background finding in mice.
There is no evidence that this cell atypia progresses or is preneoplastic.
From karyo- + -megaly . ( cytology) The condition of having an enlarged cell nucleus .
As the cell grows the large size of the nucleus appears to diminish, but in some cases karyomegaly exists, as in the mantle of Zonites, of slugs, and of Prosobranchs, the circumcerebral tissue of snails, and the tissue around the otocyst in Cyclostoma.
Figure 2 Karyomegaly in a female B6C3F1 mouse from a subchronic study.
Arrow indicates enlargement of hepatocyte cytoplasm and nucleus. show enlargement of both hepatocyte cytoplasm and nuclei.
The change is throughout the hepatic lobule but is more prominent in the centrilobular areas.
The increase in nuclear size is .
