Preoperative discrimination of tumour stage in clear cell carcinoma of the ovary using computed tomography and magnetic resonance imaging

OBJECTIVES: Clear cell carcinoma (CCC) of the ovary shows distinct clinical characteristics depending on the stage. We aimed to investigate the imaging predictability for tumour stage in CCC. PATIENTS AND METHODS: Fifty-six tumours in 48 patients with pathologically proven CCC were enrolled. CCCs were divided into early and advanced stage based on the International Federation of Gynecology and Obstetrics staging. Two reviewers assessed diverse computed tomography (CT) and magnetic resonance imaging (MRI) findings associated with CCC: laterality, size, margin, cystic component features (internal architecture, CT attenuation, and T1 signal intensity of MRI), solid component features (amount, shape, growth pattern, signal intensity, enhancement pattern, and diffusion restriction), and secondary manifestations (ascites, endometriosis, and venous thromboembolism). RESULTS: There was a statistically significant difference between early and advanced CCC in laterality (p = 0.011), CT attenuation (p = 0.03), and T1 signal intensity of the cystic component (p = 0.04), T2 signal intensity of the solid component (p = 0.006), ascites (p < 0.001), coexisting endometriosis (p = 0.032), and venous thromboembolism (p = 0.011). Early-stage CCC tended to show unilaterality, higher CT attenuation values and T1 hyperintensities of the cystic component and endometriosis. Advanced-stage CCC showed bilaterality, T2 hyperintensities of the solid component, ascites, and venous thromboembolism. Laterality, CT attenuation of the cystic component, T2 signal intensity of the solid component, coexisting endometriosis, and ascites are independent predictors for advanced CCC. CONCLUSIONS: Imaging features can be a significant predictor for the discrimination of preoperative tumour staging in CCC.