Differential diagnosis of benign ovarian cysts using tumor markers in serum and cyst fluid

Background: Differentiating the type of benign ovarian cyst can result in better care. Aims: To measure CA-125, CA 19-9, Carcinoembryonic Antigen (CEA) and Alpha-fetoprotein (AFP) in serum and cyst fluid of patients with benign ovarian cysts and whether these biomarkers can be used to identify the type of the cyst. Methods and materials: Patients with benign ovarian cysts undergoing laparoscopic cystectomy were included. Cyst types were determined histologically. Levels of CA 125, CA 19-9, CEA and AFP were measured in serum and cyst fluid. Results: 98 cysts (25 functional, 12 endometrioma, 15 dermoid, 28 mucinous cystadenoma, 18 serous cystadenoma) were evaluated. There was a significant difference in levels of CA 125 and CA 19-9 in serum and CA-125, CA 19-9 and CEA in cyst fluid. For diagnostic purposes, a value of ≥35 IU/mL for serum CA 125 predicted endometriomas with a sensitivity of 91.7% and a specificity of 91.9%. A value of ≤22.5 IU/mL for cyst fluid CA 19-9, predicted functional cysts with a of sensitivity of 92% and specificity of 95.2%. A value of ≥100 ng/mL for cyst fluid CEA, predicted mucinous cysts with a sensitivity of 96.4% and specificity of 96.7%. Conclusion: Levels of CA-125, CA 19-9 and CEA in serum and cyst fluid of patients with benign ovarian cysts can be used as a diagnostic tool in patient evaluation with acceptable sensitivity and specificity. This finding can be used in conjunction with other methods such as ultrasound, especially in cases that are harder to diagnose. Keywords: Ovarian cyst, tumor marker, CA 125, CA 19-9, CEA, AFP