MUC16 and cystadenoma: To explore variations in serum CA125, HE4, ROMA index, and Serum sEV levels within the subcategories of benign diseases, we further divided the benign group into four subgroups: ovarian endometriosis group (73 cases), mature teratoma group (48 cases), cystadenoma group (34 cases), and other benign tumors group (including luteal cysts, luteinized cysts, follicular cysts, haemorrhagic cysts, etc., totaling 35 cases).