Benign ovarian tumor that arises from surface epithelium and underlying cortical connective tissue of the ovary.

These are rare benign ovarian tumors representing less than 2% of benign ovarian neoplasms. Originally thought to be fibrous variants of cystadenomas (the most common benign epithelial ovarian neoplasms), these tumors actually originate from the surface epithelium as well as the underlying cortical connective tissue of the ovary.

Cystadenofibromas are often complex in their sonographic appearance. They are at least partly if not predominantly cystic and may contain septations, solid areas, and nodularity. The most common appearance (69% in a series of 58 cases) is a unilocular cyst with papillations that project into the lumen but do not demonstrate blood flow using color Doppler. The appearance, however, can be quite variable, and can mimic the appearance of a malignancy, with thick septations and blood flow in the solid areas. Occasionally, ovarian cystadenofibromas may be borderline tumors (5 in a series of 47 tumors).