A Clinicopathologic Study of 11 Cases with Malignant Transformation Arising in Mature Cystic Teratomas

Kang, Woo Dae; Yun, Dae Seog; Lee, Jae Young; Kim, Seok Mo; Choi, Ho Sun

Abstract

OBJECTIVE
There have been few studies concerning the clinical pathology of malignant transformation arising from ovarian mature cystic teratoma. Thus, the objective of this study is to determine clinicopathologic factors affecting survival in this rare tumor.
METHODS
From November 1992 to December 2002, 11 patients with malignant transformation arising from ovarian mature cystic teratoma were treated at Departments of Obstetric and Gynecology in Chonnam National University Hospital. Demographic characteristics, symptoms, signs, stage, mode of therapy and results of follow up were reviewed retrospectively.
RESULTS
There were 11 cases of the malignant transformation of ovarian mature cystic teratomas out of 637 cases of mature cystic teratomas (1.7%). The average age was 50.6 years. Histologically, 7 out of the 11 cases were squamous cell carcinoma (63.7%). There was no specific clinical symptom but palpable abdominal mass was the most frequent complaint (5 cases, 45.4%). As for the stage of disease, 8 cases were in stage Ia (72.7%) and the other three cases were in stage Ic, IIb and IIc respectively. All the patients received surgery, and 7 of them had chemotherapy and 2 both chemotherapy and radiation therapy at the same time. All patients in stage I survived until the period of follow-up and their average survival time was 31.8 months. One patient in stage IIc died of intestinal obstruction in 9 month from the surgery and the average survival time of two patients in stage II was 8.5 months.
CONCLUSION
The mechanism of the malignant formation arising in ovarian mature cystic teratomas is not clear but considering the fact that 80% of mature cystic teratomas are diagnosed during the reproductive age malignant transformation seems to be related to the long-term presence of non-removed mature cystic teratomas in abdomen. Accordingly, it is considered helpful for preventing and early detection of the malignant transformation to have regular ovary examination through pelvic ultrasonogram during the reproductive age.