Ovarian adenofibromas and cystadenofibromas: magnetic resonance imaging findings including diffusion-weighted imaging.

Background: Ovarian adenofibromas (AF) and cystadenofibromas (CAF) belong to the surface epithelial-stromal tumors, and may appear as solid, or solid and cystic masses mimicking ovarian cancers.

Objective: To evaluate the capability of magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurement for the diagnosis of ovarian AF/CAF.

Methods: Magnetic resonance manifestations of 13 cases of ovarian AF/CAF were retrospectively evaluated. DWI was obtained in all 13 lesions, and mean ADC values in 11 lesions were compared with those in solid portions of 27 ovarian cancers. Results Neither case with AF/CAF revealed high signal intensity on DWI, whereas all ovarian cancers showed high signal intensity on DWI. The ADC values in the solid portions of AF/CAF were significantly higher than those of ovarian cancers (P < 0.001). A cut-off value of 1.20 × 10(-3) mm(2)/s for AF/CAF had a sensitivity of 82%, specificity of 93%, positive predictive value of 82%, and negative predictive value of 93%.

Conclusions: DWI with ADC measurement may be helpful in differentiating AF/CAF from ovarian cancers.