Left ovarian Brenner tumor.

Ovarian Brenner tumors are uncommon neoplasms of the ovary, representing approximately 2% of all ovarian neoplasms. Nowadays there is general agreement that Brenner tumors are derived from the surface epithelium of the ovary or the pelvic mesothelium through transitional cell metaplasia. Association with other surface-derived neoplasms, either in the ipsilateral or contralateral ovary, is reported in 30% of the cases. We report a case of benign ovarian Brenner tumor and discuss the typical features on magnetic resonance imaging (MRI) and computed tomography (CT) scan as well as the differential diagnosis.