Diversity in size and signal intensity in multilocular cystic ovarian masses: New parameters for distinguishing metastatic from primary mucinous ovarian neoplasms

Abstract

Purpose To differentiate primary mucinous ovarian neoplasms from metastatic ones with MR using diversity in size and signal intensity of multilocular cystic masses. Materials and Methods Twenty-eight cases of primary malignant or borderline mucinous malignant neoplasms and 14 metastatic ovarian tumors were retrospectively reviewed. We analyzed whether the tumor was unilateral or bilateral, the diversity in the size and signal intensity of each loculus in multilocular tumors, namely the size ratio of the smallest/largest loculus (size diversity ratio), and the standard deviation of the signal intensity at the level with the most varying signal on T2-weighted images within tumors (signal diversity ratio). We performed statistical analysis using the Mann-Whitney U-test. Results Bilateral tumors were more commonly observed among metastatic tumors than primary mucinous tumors (2/28 in primary versus 11/14 in metastatic, P < 0.01). The size diversity ratio was higher in primary mucinous tumors than in metastatic tumors (mean, 50.2 versus 23.2; P < 0.01). The signal diversity ratio was also higher in primary mucinous tumors than in metastatic tumors (334.3 versus 231.2; P < 0.01). Conclusion Bilateral tumors were more common among metastatic tumors, which tended to be composed of cysts of uniform sizes and signal intensities compared with those of primary mucinous tumors. Copyright © 2013 Wiley Periodicals, Inc.