MRI-based morphology of ovarian clear cell carcinomas

Ovarian clear cell carcinoma (CCC) is a distinct histological subtype of epithelial ovarian cancer characterized by unique biological behavior and heterogeneous clinicopathological features. In contrast with other epithelial ovarian malignancies, CCC often presents at an early stage but exhibits significant resistance to conventional platinum-based chemotherapy, underscoring the importance of accurate preoperative identification to optimize surgical management. This review provides a comprehensive overview of the imaging spectrum of CCC, emphasizing correlations between various magnetic resonance imaging (MRI) morphologies and their underlying histopathological architectures. We propose a classification system comprising 9 MRI-based morphological types, ranging from classic unilocular cystic lesions with polypoid mural nodules to entirely solid masses. These imaging patterns are closely linked to two primary pathogenic pathways: the endometriotic cyst pathway and the adenofibromatous pathway. The former typically manifests as cystic lesions with eccentric growth, whereas the latter is more commonly associated with solid or tubulocystic masses exhibiting a characteristic black sponge-like appearance on T2-weighted imaging, reflecting abundant fibrous stroma. The review also highlights emerging and less commonly described imaging signs, including the renal corticomedullary contrast-like appearance associated with stromal edema. Integration of diffusion-weighted imaging and apparent diffusion coefficient values with these morphological signatures may further refine diagnostic accuracy and improve lesion characterization. A thorough understanding of these MRI-based morphological patterns and their radiological-pathological correlations is essential for the accurate preoperative diagnosis of CCC, and has potential implications for patient stratification, surgical planning, and overall clinical outcomes.