Objective:To evaluate the value of sonographic morphology indexing (MI) system and serum CA-125 levels in the assessment of the malignancy risk in patients with ovarian tumors. Methods: From September 2000 to July 2006, 202 patients who underwent surgery for ovarian tumors were reviewed retrospectively. In all patients, the MI score and serum CA-125 level were measured preoperatively. The association of the final pathologic diagnosis with the MI score and serum CA-125 level were examined. Results: There were 26 malignant tumors out of 141 ovarian tumors with a MI ≥5 (18%). With a cut-off value of 5, the sensitivity, specificity, PPV, and NPV of MI scores were 0.743, 0.293, 0.181, and 0.845, respectively. There were 22 malignant tumors out of 54 ovarian tumors with serum CA-125 ＞30 u/ml (41%). With a cut-off value of 30 u/ml, the sensitivity, specificity, PPV, and NPV of serum CA-125 level were 0.667, 0.808, 0.407, and NPV 0.925, respectively. On ROC curve, the optimal cut-off value of MI score was 6.5-7.5 and that of serum CA-125 level was 25.6-28.5 u/ml. With a cut-off value of 7, the sensitivity and 1-specificity of MI score were 0.875-0.917 and 0.023-0.203, respectively. After the exclusion of teratoma cases, the sensitivity and 1-specificity of MI score were 0.875-0.917 and 0.046-0.138, respectively. With a cut-off value of 25.6-28.5 u/ml, the sensitivity and 1-specificity of serum CA-125 level were 0.958 and 0.203-0.215, respectively. Conclusion: The sonographic MI system is an accurate and simple method to differentiate a malignant tumor from a benign ovarian tumor. The accuracy of the sonographic MI system improved when the serum CA-125 level was considered and ovarian teratomas were excluded.
