Ovarian serous cystadenofibroma with stromal sex cord elements: report of a unique case.

This report describes an ovarian serous cystadenofibroma, in a postmenopausal woman, which exhibited extensive sex cord differentiation, in the form of solid and hollow tubules resembling Sertoli cell elements, within the stroma. The sex cord elements, which were located just beneath the epithelium, were positive with both alpha inhibin and calretinin and negative with epithelial membrane antigen. They were also CD56 positive but negative with other neuroendocrine markers. True sex cord structures or sex cord-like elements have been described in ovarian adenosarcomas and pure stromal tumors, especially fibromas. However, as far as we are aware, these elements have not been reported in a serous cystadenofibroma. The endometrium exhibited simple hyperplasia, perhaps secondary to estrogenic activity of the sex cord elements. We discuss the significance of CD56 positivity of the sex cord elements.