Malignant Müllerian mixed tumor of the ovary associated with yolk sac tumor, neuroepithelial and trophoblastic differentiation (teratoid carcinosarcoma).

This paper reports a unique stage IV complex ovarian carcinosarcoma in a 69-year patient that had malignant mixed müllerian epithelial and mesenchymal components and also other malignant differentiation such as neuroectodermal (small cell, neuroendocrine, neuroglial, neuronal, and melanocytic) and endodermal (yolk sac tumor) tissues and trophoblastic cells. As its phenotype comprised elements derived embryologically from the 3 germ layers, it posed the problem of differentiating it from a teratoma originated from germ cells, with which it shared a trilaminar type differentiation. It was different from a teratoma as it coexisted with, and possibly originated from, a somatic tumor, namely a characteristic endometrioid adenocarcinoma. All neoplastic tissue patterns present in the neoplasm were malignant per se without an apparent gradient of maturation or presence of organoid structures.