Malignant transformation of mature cystic teratomas is rare, with squamous cell carcinoma being the most common type. The prognosis is generally poor when disease has spread beyond the ovary. We conducted this study to review our experience with this disease and describe our current treatment modality.

During a 22-year period (1983-2005), we identified 17 women treated for squamous cell carcinoma arising in a mature cystic teratoma of the ovary. All pathologic diagnoses were confirmed at our institution. A retrospective chart review and comprehensive review of the literature were conducted.

The median age was 55 (mean, 54.8; range, 37-75). Eight cases were stage I, 5 were stage II, and 4 were stage III. Mean tumor size was 14.2 cm. All patients underwent surgery, with positive lymph nodes noted in 0 of 10 cases that included lymph node dissection. Ten patients received adjuvant treatment-6 with chemotherapy and 4 with chemoradiation. Six patients had recurrent disease in the pelvis after adjuvant treatment. Four patients died of disease. The overall 1-year survival rate was 60%. The 4 patients with stages IA-IIB disease treated with adjuvant platinum-based chemotherapy and radiation survived at 12-56 months' follow-up.

Squamous carcinomas arising in mature cystic teratomas are commonly large ovarian tumors that occur in perimenopausal women and often present as an incidental pathologic finding. While the prognosis seems highly dependent on surgical stage, there is a lack of consensus in the literature regarding adjuvant treatment. Platinum-based chemotherapy with pelvic radiation may be a reasonable adjuvant therapy for early-stage disease.