Ultrastructural study of liver invasion by Novikoff hepatoma.

The ultrastructural aspect of liver invasion by Novikoff hepatoma transplanted in rat liver was investigated. Invasion of liver parenchyma was seen to begin by the projection of cytoplasmic processes from the tumor cells into the neighboring hepatic cells. This infiltration was, at times, associated with fragmentation of the invaded liver cells. Moreover, the tumor cells showed phagocytosis of hepatic cell debris and erythrocytes. These findings appear to indicate the active and destructive character of the process of liver invasion by Novikoff hepatoma.