Brenner tumor of the ovary - ultrasound features and clinical management of a rare ovarian tumor mimicking ovarian cancer.

OBJECTIVES: To describe the ultrasound features of benign Brenner tumor in the background of complex clinical and histopathological pictures.

MATERIAL AND METHODS: We retrospectively identified patients with histologically confirmed benign Brenner tumor of the ovary who were treated in our institution in 2003-2016, and for whom complete imaging, clinical, perioperative and histopathological data were available in the database. Ultrasound findings were drawn from images and reports using terms and definitions of the International Ovarian Tumor Analysis group and pattern recognition description was applied.

RESULTS: Twenty-three patients were identified, most postmenopausal and asymptomatic. On ultrasound, 19/23 tumors were found unilaterally, 4/23 bilaterally, and 82% of tumors were detected in the left ovary. Most Brenner tumors (16/23) contained solid components and revealed no or minimal blood flow by subjective color score upon Doppler examination (19/23, 83%). Calcifications with shadowing were observed in 57% of all Brenner tumors and in 81% of tumors containing solid components. The complex appearance of the tumor misled the sonographers to describe the mass as malignant in 9 cases (39%), and frozen section was performed perioperatively. Surgery was performed via laparoscopy in 11 (48%) and via laparotomy in 12 (52%) cases.

CONCLUSIONS: The complexity of the ultrasound picture, consisting of features like calcifications with acoustic shadowing, a poorly vascularized solid mass, and a left-sided localization could be signs of a benign Brenner tumor and could preop-eratively help to differentiate between benign and malignant tumor.