Changes in tumor morphology in one human endometrial carcinosarcoma heterotransplanted into nude mice

Tissue material from one human endometrial carcinosarcoma was transplanted into nude mice. In the third passage two independent tumor lines developed, which continued to grow independently. After the fifth passage one line could be diagnosed histopathologically as a poorly differentiated adenocarcinoma without sarcoma components, while the other line was still a carcinosarcoma. It was assumed that the development of two histologically different tumor lines could be due to clonal selection induced by the new host.