Clinical Research Directory

Inclusion Criteria: * Female participants. * Participants with an ovarian/adnexal mass who are planned to undergo, for the first time at the current center, surgery or biopsy/pathologic sampling related to the current lesion, with an expected pathologic diagnosis available as the reference standard. * Imaging evaluation during screening suggests a unilateral or bilateral, unilocular or multilocular cystic-solid or solid ovarian/adnexal mass requiring differential diagnosis. * An adequate peripheral blood sample can be collected before the first surgery or before initiation of any systemic anti-tumor treatment for the current ovarian/adnexal mass, and the sample can be processed and stored within the required time according to the unified study procedures. * Clinical data and postoperative pathologic results are expected to be sufficiently complete to provide key information for subsequent analyses. * The participant or her legally authorized representative voluntarily signs written informed consent after being fully informed. Exclusion Criteria: * The participant has already received systemic anti-tumor treatment for the current ovarian/adnexal lesion under evaluation, such as chemotherapy, targeted therapy, immunotherapy, or radiotherapy, or has already undergone definitive tumor resection or comprehensive staging surgery, and is undergoing surgery only for residual or recurrent lesions. * No pathologic diagnosis is ultimately obtained for the current ovarian/adnexal mass, or no analyzable pathologic conclusion can be established. * Imaging findings at screening are highly typical of benign mature cystic teratoma. * Ovarian cancer combined with another malignant tumor. * There are obvious noncompliances during sample collection, transport, or processing, resulting in severe hemolysis, contamination, or seriously insufficient sample volume, such that the sample cannot meet quality control requirements for cfDNA methylation testing or subsequent analyses. * Any other condition that, in the investigator's judgment, makes the participant unsuitable for enrollment.