Diagnosis of squamous cell carcinoma arising from mature cystic teratoma of the ovary.

BACKGROUND

The prognoses of patients with squamous cell carcinoma of the ovary are quite poor. However, preoperative diagnosis is difficult due to the rarity of this tumor and its similarity to mature cystic teratoma (MCT). The objective of this study was to assess the value of tumor markers and clinical characteristics in making a differential diagnosis between MCT and squamous cell carcinoma arising from MCT.

METHODS

Between September 1979 and June 1996, 37 patients with ovarian squamous cell carcinoma arising from MCT were treated by the Tokai Ovarian Tumor Study Group. The authors evaluated tumor markers, tumor size, and age as parameters for differentiation between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was calculated as the sensitivity multiplied by the specificity.

RESULTS

There were significant differences (P < or = 0.0002) in age, tumor size, and levels of squamous cell carcinoma antigen (SCC), CA125, and CEA, as well as a significant difference (P < or = 0.0396) in the CA19-9 level between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was highest for SCC (63.0%), followed by CA125 (50.7%). Receiver operating characteristic (ROC) curves demonstrated that CEA was the best screening marker for squamous cell carcinoma arising from MCT, whereas age and tumor size were better markers than CA125 or CA19-9. The optimal cutoff values for age and tumor size were 45 years and 99 mm, respectively, according to ROC analysis.

CONCLUSIONS

These findings demonstrate that age and tumor size are important factors in making a differential diagnosis. In addition, SCC and CEA levels should be measured in patients age 45 years or older who have an MCT-like ovarian tumor larger than 99 mm in greatest dimension.