Characteristics and Treatment Outcomes of Patients with Malignant Transformation Arising from Mature Cystic Teratoma of the Ovary: Experience at a Single Institution

Background: Malignant transformation arising in mature cystic teratoma (MCT) is one of the most seriouscomplications of MCT. Squamous cell carcinoma is the most common malignant change. Some clinical findingssuch as advanced age group and large tumor size are significant risk factors of malignant transformation.This study was conducted in order to evaluate characteristics, cell types, treatment and outcome of malignanttransformation arising from dermoid cysts in our institution. Materials and
Methods: A retrospective chart reviewwas performed. General characteristics, operative data, procedure, operative finding and operative outcomewere analyzed. Statistical assessment was performed with SPSS version 17.0, using mean, mode, median andpercentage to describe those data.
Results: During the 10 years period, 11 cases of malignant transformation froma total of 753 cases (1.46% incidence) of MCT were reviewed. Mean age of the patients was 41.2 years (SD 4.34,range 24-70). The most common presenting symptom was a palpable mass (8 cases; 72.7%). Primary surgicalstaging was performed in 4 patients (36.4%). Re-staging was conducted in the other 4. Complete cytoreductionwas obtained in 45.5% (5 cases) and optimal surgical resection was obtained in 36.4% (4 cases). Mean tumorsize was 14.1 cm. (SD 1.55, range 6-20). Squamous cell carcinoma was found in 36.4% (4 cases) and mucinouscancer in the other 4. More than half of them were stage Ia (54.5%, 6 cases). All patients whose stage morethan Ia received chemotherapy (45.5%). Mean disease free survival was 5.53 years (1.32, 0.3-10).
Conclusion:According to our study, the incidence of malignant transformation was consistent with previous studies. Thecommon malignant transformation histologic types are both squamous and mucinous carcinoma which differedfrom previous reports. Early detection for early stage disease and optimal surgery are important for long termsurvival.