Mixed mesodermal tumor of the ovary with carcinoembryonic antigen and alkaline phosphatase production. Histochemical, autoradiographic, and electron microscopic studies of heterotransplanted tumors in athymic nude mice.

A mixed mesodermal tumor of the ovary with carcinoembryonic antigen (CEA) and alkaline phosphatase (ALP) production was serially heterotransplanted into nude mice. The original tumor was diagnosed as homologous tumor, with sarcomatous component consisting of nonspecific spindle-shaped cells. These features were basically retained in the transplanted tumors, including CEA and ALP production. But, heterologous, chondrocytic-differentiated foci were found in the tumors at the third and sixth passages. Transitional-type cells from sarcomatous to carcinomatous cells were sometimes found in the transplanted tumors by light and electron microscopy. Ciliated sarcomatous cells, which may also represent the epithelial differentiation of sarcomatous cells, were found in the tumors at first passage. The current results support the combination tumor theory, which means that both the carcinomatous and sarcomatous components are of common stem cell origin.