Malignant Transformation of Ovarian Mature Cystic Teratoma

Abstract

Objectives: Malignant transformation arising from ovarian mature cystic teratomas (MCT) is rare, occurring in 1-2% of cases. The aim of this study was to review the outcome of women with this disease. Methods: A single institution retrospective chart review was performed from 1986 to 2017. Clinical characteristics, management and treatment outcome were analysed. Results: During the study period, 17 women with MCT with malignant transformation were identified. The median age was 53 years (Range 26-87 years). Of 17 women, 11 (64.7%) had stage I, 3 (17.6%) had stage II and 3 (17.6%) had stage III disease. All women underwent primary surgery, of which one had fertility-sparing surgery. Malignant transformation included 12 (70.6%) squamous cell carcinoma (SCC) and one case each of adenosquamous carcinoma, mucinous adenocarcinoma, thyroid carcinoma, strumal carcinoid and malignant melanoma. Seven (41.2%) women received adjuvant chemotherapy and one (5.9%) woman with residual SCC after cytoreductive surgery had adjuvant radiotherapy followed by chemotherapy. Median follow-up time was 4.2 years (Range 0.5-32.3 years). Five (29.4%) women had disease recurrence of which 2 were treated with cytoreductive surgery followed by chemotherapy and 3 had palliation due to extensive disease and poor premorbid. The 5-year overall survival was 61% and median survival was 24.6 years (95% Confidence Interval 0-56.6). Conclusions: The most common type of malignant transformation of ovarian mature cystic teratoma is squamous cell carcinoma. The prognosis is generally poor when the disease has spread beyond the ovary. The role of chemotherapy or radiation therapy in the management of these tumours are unclear.