Personalized Imaging-Based Risk Stratification of Cystic Ovarian Tumors: Multimodality Assessment, O-RADS, Diagnostic Pitfalls, and Individualized Management

Background/Objectives: Cystic ovarian and adnexal tumors encompass benign, borderline, primary malignant, and secondary neoplasms with substantial overlap in morphology. Misclassification can lead either to unnecessary aggressive surgery or to delayed oncologic referral, particularly when fertility preservation, previous malignancy, or acute complications modify the clinical stakes. This review critically examines how multimodality imaging and standardized risk-stratification systems can support individualized assessment and management. Methods: A structured narrative review of PubMed/MEDLINE literature and current society guidance was updated through 1 October 2026. Priority was given to consensus documents, multicenter validation studies, systematic reviews, meta-analyses, and recent imaging–pathology correlation studies addressing O-RADS US, IOTA/ADNEX approaches, CT, multiparametric MRI, O-RADS MRI, mucinous tumors, ovarian metastases, and fertility-sparing management. Three illustrative multimodality cases with established final diagnoses are included to exemplify clinically relevant diagnostic and management scenarios rather than as an analytic cohort. Results: O-RADS US provides highly sensitive first-line risk stratification, whereas O-RADS MRI offers a more balanced sensitivity–specificity profile for sonographically indeterminate lesions. The main residual diagnostic challenge is the intermediate-risk phenotype, in which benign cystadenoma, borderline tumor, invasive carcinoma, and metastatic disease may share multilocularity, mural protrusions, heterogeneous mucinous or hemorrhagic content, and diffusion-related signal abnormalities. Prior malignancy, bilaterality, rapid interval growth, discordant compartmental progression, and acute complications can substantially alter the pretest probability and should influence interpretation. Conclusions: Personalized assessment requires integration of standardized imaging categories with lesion phenotype, serial behavior, age, symptoms, biomarkers, oncologic history, surgical risk, and reproductive priorities. The goal is not merely to label an adnexal mass, but to identify the safest next diagnostic and therapeutic step for the individual patient.