MR Imaging Findings of Ovarian Cystadenofibroma and Cystadenocarcinofibroma: Clues for the Differential Diagnosis

OBJECTIVE: We wanted to assess the MR imaging findings of ovarian cystadenofibroma and cystadenocarcinofibroma, and we wanted to find clues for making the differential diagnosis between them. MATERIALS AND METHODS: The MR images of 12 pathologically proven cystadenofibromas and two cystadenocarcinofibromas were reviewed, with a focus on the internal architecture, signal intensity and enhancement. RESULTS: All the tumors appeared as multilocular cysts, except for a single unilocular cystic mass and a single solid mass. The previously reported characteristic MR findings of cystadenofibroma (a multilocular cystic mass with a T2-dark-signal-intensity solid component containing small cystic locules) were found in only 43% of the tumors (6/14). Diffuse or partial thickening of the cyst wall with T2-dark signal intensity without a definite solid component was as common as the previous reported findings (6/14). Two cystadenocarcinofibromas showed more prominent solid portions with higher T2-signal intensities and stronger enhancement than did the cystadenofibromas. CONCLUSION: Diffuse or partial thickening of the cyst wall with dark-signal-intensity in multilocular cystic masses may suggest ovarian cystadenofibroma, and this type of appearance may be as common as the previously reported characteristic appearance. A prominent solid component with a higher T2-signal intensity and strong enhancement are the typical findings of cystadenocarcinofibroma.