Objective  To analyze the risk factors and the clinical characteristics of borderline ovarian tumors(BOTs).

  Methods  A total of 275 patients who were diagnosed as BOTs were selected as study objects. Another 275 patients diagnosed as ovarian benign epithelial tumor (BETs) by surgical pathology were selected as controls. The clinical data such as age, fertility, symptoms and signs, results of ultrasonography, serum tumor markers, surgical and pathological results were collected and compared. The risk factors of BOTs were analyzed. According to postoperative pathological types, some BOTs patients were divided into mucinous borderline ovarian tumors (MBOTs) group and serous borderline ovarian tumors (SBOTs) group, and the clinical characteristics of the two groups were compared.

  Results  Ultrasonographic findings showed that solid tumor, papilla-shaped protuberance on the cystic wall, blood flow signals and elevated carbohydrate antigen 125 (CA125) and carbohydrate antigen 199(CA199) were independent risk factors for BOTs. Compared with BETs, there were no significant differences in tumor maximum diameter, location of tumors, multilocular tumors, and serum carcinoembryonic antigen level in BOTs(P > 0.05). The proportions of the maximal diameter ≥10 cm, multilocular tumors, blood flow signal and the increased CA199 in patients of the MBOTs group were higher than those in the SBOTs group, while the proportions of bilateral tumor, papilla-shaped protuberance on the cystic wall and elevated CA125 were lower than those in the SBOTs group(P < 0.05).

  Conclusion  The ultrasonographic findings show that solid components, multilocular tumors, papilla-shaped protuberance, blood flow signal and elevated serum levels of CA125 and CA199 occur in BOTs patients, and they are helpful to distinguish BOTs from BETs. The maximum diameter of the tumor ≥10 cm, multilocular tumors and blood flow signal suggest higher possibility of MBOTs. MBOTs patients are more likely to have elevated CA199, while those with SBOTs are more likely to have elevated CA125.