A case of mixed mesodermal tumor of the uterus with alpha-fetoprotein production

A case of mixed mesodermal tumor of the uterus with alpha-fetoprotein (AFP) production in a postmenopausal woman is reported, with special reference to its histogenesis. Judging from the serum AFP levels, the AFP content of the tumor and immunohistochemical localization of AFP in the tumor, AFP was produced by the tumor. The observation that in this patient AFP existed exclusively in carcinoma cells strongly supports the hypothesis that malignant transformation of Müllerian epithelial and stromal cells in mixed mesodermal tumors of the uterus occurs independently after the primitive mesenchymal cells have differentiated towards epithelial and stromal components.