Purpose: To explore the clinical characteristics and identify potential prognostic factors associated with malignant transformation (MT) of ovarian mature cystic teratoma (MCT). Materials and Methods: This study analyzed 23 patients with MT of ovarian MCT at the present center during a ten-year period. The data were analyzed using Kaplan-Meier method. Results: The incidence of MT of ovarian MCT was 1.3%. The mean follow-up time was 44 months. The overall five-year survival rate was 69.6%. Patient age, tumor size, histology type, disease stage, and postoperative residual disease had a significant prognostic impact on overall survival. Elevated CA125 was associated with adverse outcomes. Conclusion: Age of patient, size of tumor, serum CA125, CA199, CEA, and SCCA levels, and presence of HPV are potential predictors of MT of ovarian MCT. Intraoperative frozen section analysis is essential in cases of suspected MT. Patient age, tumor size, histology, disease stage, and post-operative residual tumors are important factors affecting prognosis. CA125 level is associated with a poor prognosis.
