Preoperative diagnosis of malignant transformation arising from mature cystic teratoma of the ovary.

OBJECTIVE

Mature cystic teratoma of the ovary (MCT) is the most common ovarian cystic disease in young women. Although it is a rare occurrence, some cases develop malignant transformation (MT), which results in serious consequences. However, MT is currently diagnosed only by postoperative pathology in most cases. We have conducted a retrospective study in an attempt to seek the factor to diagnose MT from MCT prior to surgery.

STUDY DESIGN

Eighty-one patients with MCT and 39 patients with MT were entered in this study. Patient's age, tumor size, serum CEA levels, and serum SCC levels were tested by the Mann-Whiteney U test. Sensitivity and specificity were calculated, and the most suitable point was searched from the receiver operating characteristic (ROC) curve.

RESULTS

A significant difference was recognized in both patient's age and serum SCC level (P < 0.0001). For a patient less than 40 years old, the sensitivity to MT was 95%, and then the specificity to MT was 63%. When the standard value of the SCC level of the serum was established as 2.5 ng/ml, the sensitivity to MT was 80% and the specificity to MT was 94%. We apply two criteria at the same time (serum SCC levels less than 2.5 ng/ml and patient's age less than 40 years old). The sensitivity for MT was 77% and specificity was 96%.

CONCLUSION

The combination of the two criteria which are patient's age (under 40 years old) and serum SCC level (under 2.5 ng/ml) was considered a suitable marker for differential diagnosis between MCT and MT. Further the possibility for MT is quite low when the patient is 39 years old or younger and the serum SCC level is under 2.5 ng/ml. When any patient satisfies this condition, laparoscopic surgery will be able to be planned safely.