Figure 4. Histological characteristics of HCC in 5/M and 9/M woodchucks at 55 months post-inoculation with 100 WHV virions.

(A–C) Representative alterations encountered in cancerous liver tissue of animal 5/M and (D–F) in animal 9/M. Well-defined trabeculae formed by hepatocyte-like cells are evident and demarked with dashed lines (B and F) or by arrows (B). Arrow heads point at frequently observed binuclear cells resulting from cell divisions (C). Accumulation of lipid droplets is apparent in almost all hepatocytes of both animals. Hepatic tissue was obtained at autopsies done in the late fall at the time when storage of fat in the liver is completed prior to physiologically occurring hibernation, although the animals were awake and physically active during the study period. Paraffin sections stained with hematoxylin-eosin. Original magnifications x100 for A and D and x250 for B, C, E and F.