MRI for discriminating metastatic ovarian tumors from primary epithelial ovarian cancers

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Aims

To find specific magnetic resonance imaging (MRI) features to differentiate metastatic ovarian tumors from primary epithelial ovarian cancers.

Methods

Eleven cases with metastatic ovarian tumors and 26 cases with primary malignant epithelial ovarian cancers were retrospectively studied. All features such as patient characteristics, MRI findings and biomarkers were evaluated. The differences including laterality, configuration, uniformity of locules, diffusion weighted imaging (DWI) signal of solid components and enhancement of solid portions between metastatic ovarian tumors and primary epithelial ovarian cancers were compared by Fisher’s exact test. Median age of patients, the maximum diameter of lesions and biomarkers were compared by the Mann-Whitney test.

Results

Patients with metastatic ovarian tumors were younger than patients with primary epithelial ovarian cancers in the median age (P = 0.015). Patients with bilateral tumors in metastatic ovarian tumors were more than those of primary epithelial ovarian cancers (P = 0.032). The maximum diameter of lesions in metastatic ovarian tumors was smaller than that of primary epithelial ovarian cancers (P = 0.005). The locules in metastatic ovarian tumors were more uniform than those of primary epithelial ovarian cancers (P = 0.024). The enhancement of solid portions in metastatic ovarian tumors showed more moderate than that of primary epithelial ovarian cancers (P = 0.037). There was no statistically significant difference between the two groups in configuration, DWI signal of solid components and ascites. Biomarkers such as CA125 and human epididymis protein 4 (HE4) in metastatic ovarian tumors showed less elevated than that of primary epithelial ovarian cancers.

Conclusions

Significant differences between metastatic ovarian tumors and primary epithelial ovarian cancers were found in the median age of patients, laterality, the maximum diameter of lesions, uniformity of locules, enhancement patterns of solid portions and biomarkers. Metastatic ovarian tumors usually presented in the younger patients, smaller-sized, more bilateral lesions, more uniform of locules, more moderate enhancement of solid portions, and less elevated levels of CA125 and HE4 than those of primary epithelial ovarian cancers.

Background

The optimal management and prognosis of metastatic ovarian tumors depend on the origin of the primary tumor [1], [2].

For primary ovarian cancers, management will be based on cytoreductive surgery and systemic therapy (depending on stage). Therefore, preoperative discrimination is very critical. However, by now, it is difficult to discriminate these tumors by imaging, or even by histopathology in some cases, as macroscopic and microscopic features of metastatic ovarian tumors and primary epithelial ovarian cancers are often similar. Therefore, they cannot be definitively classified without further clinical evaluations [3], [4]. Histological preoperative diagnosis is now and then impossible because there is a risk of dissemination of primary ovarian cancer on an early stage otherwise. In general, the therapy methods and prognoses of metastatic ovarian tumors are different from those of primary epithelial ovarian cancers [5]. Therefore, discriminations between them are very critical. However, there is a lack of comprehensive imaging studies concerning the distinctions. Magnetic resonance imaging (MRI) is a useful tool for investigation and description of characteristic signs for the preoperative diagnosis of an ovarian lesion [1]. The object of this study is to detect specific MRI features of metastatic ovarian tumors that can be discriminated from primary epithelial ovarian cancers.....