Adenofibromasarcoma originating from a mural nodule of ovarian serous cystadenoma

A 83-year-old woman received bilateral salpingo-oophorectomy and hysterectomy due to a provisional diagnosis of ovarian cystic tumor. The tumor had a unilocular cystic cavity demonstrating serous cystadenoma and a solid mural nodule representing a biphasic pattern with mesenchymal and glandular components. The glandular elements were composed of benign serous cells, whereas the mesenchymal components consisted of an admixture of fibromatous stromal cells without atypia and sarcomatous overgrowth. The area of transition from a fibromatous component to sarcomatous overgrowth was identified. After a 2-year follow-up, there were no signs of tumor recurrence or systemic disease. To the authors' knowledge, this is the first reported case of adenofibrosarcoma originating from a mural nodule of ovarian serous cystadenoma.