The relation between mixed mesodermal tumors and adenocarcinomas of the ovary. An immunopathologic study.

Mixed mesodermal tumor of the ovary is a rare neoplasm. The diagnosis is made if an ovarian carcinoma contains heterologous sarcomatous differentiation. With the help of an immunopathologic stain for desmin, the intermediate filament protein of muscle cells, twenty cases of ovarian adenocarcinoma were examined for the presence of morphologically unrecognizable heterologous tumor cells. Six of twenty tumors were positive. There was no significant correlation between a number of clinical parameters and desmin positivity. The authors conclude that mixed mesodermal tumor of the ovary may not be a separate entity. Instead, there may be a single group of ovarian epithelial tumors ranging from borderline or well-differentiated carcinomas to poorly-differentiated tumors which may show homologous (carcinosarcoma) or heterologous (mixed mesodermal tumor) differentiation.