Kupffer cell sarcoma in rats after exposure to small doses of dimethylnitrosamine and N-2-acetylaminofluorene during hepatic regeneration.

During experiments to study the evolution of hepatocellular carcinoma in adult male Wistar rats by exposing regenerating livers to the action of small doses of dimethylnitrosamine (DMN) or N-2-acetylaminofluorene (AAF), several primary sarcomas of the liver were incidentally observed. The morphology and behavior of the tumors suggest their origin from Kupffer's cells. Kupffer cell sarcomas occurred more frequently when 70% hepatectomy was used as the regenerative stimulus. None of the 36 animals treated with AAF alone and 2 of the 38 rats given DMN only had this tumor.