Invasiveness, XXXX , and transplantability of @entity19 liver nodules.

@entity1 @entity8055 @entity96 @entity19 @entity5 @entity189 @entity3 @entity157 @entity652
Data are presented which show that various @entity19 liver nodular lesions, such as hyperplastic nodules, hepatocellular @entity652 , and @entity157 , differ not only morphologically but also biologically regarding their behavior in the primary and secondary hosts. The hyperplastic nodules grew slowly by expansion without affecting the integrity of the lobular structure. The @entity8055 also grew slowly by expansion but eliminated the histoid liver structure. Neither lesions metastasized to the regional lymph nodes and distant organs. Upon isogeneic transplantation, the @entity652 required a long latent period before manifesting an expansive type of growth without invasion and @entity3 . The @entity157 grew fast, destroyed surrounding parenchyma, and those showing moderately to poorly differentiated cellular morphology metastasized to regional lymph nodes and distant organs. @entity157 grew fast, invaded locally, metastasized distantly, and killed the recipients within a few weeks. Thus hepatocellular @entity652 and @entity189 represent two distinct entities both morphologically and biologically. Thus the agents should be classified according to the type of nodular liver lesions they "induce" in the @entity19 liver. The least innocuous agents would be those resulting in the development of hyperplastic nodules. They should not be labelled as hepatocarcinogens. On the other side of the spectrum should be the agents "inducing" the @entity157 and they should be classified as @entity19 liver carcinogens. The agents capable of affecting significantly the hepatocellular @entity652 but not the @entity157 should be considered as tumorigens, since they are causally related only with the benign liver lesions. Combining both benign and malignant @entity96 for statistical purposes is not justified unless each type of @entity5 has been affected in a statistically significant incidence. If this were not the case, classification of the agent should be in accordance with the type of lesions induced significantly. In order to use the induction of @entity157 in rodents as an indication of carcinogenic risk in @entity1 appropriately, one has to verify within the limits of feasibility that the identical carcinogenic effects and the subsequent events occur both in rodents and @entity1 .(ABSTRACT TRUNCATED AT 400 WORDS)
