Useful aspects of diagnosis of imprint cytology in intraoperative consultation of ovarian tumors: comparison between imprint cytology and frozen sections

BACKGROUND In the intraoperative consultation of ovarian tumors, the histological diagnosis of frozen sections (FS) of large tumors is frequently difficult because of the limited number of tumor samples. The application of imprint cytology (IC), in which samples are obtained from wide areas of the tumors, is useful for intraoperative consultation. However, the useful aspects of IC have not been clearly defined. The present study is a detailed comparison of IC and FS that clearly defines the useful aspects of IC. METHODS Fifty-five cases of ovarian tumors that were examined using both IC and FS were evaluated. The histological diagnoses consisted of benign (16), borderline (6), and malignancy (33). All of the malignant tumors consisted of various types of carcinoma. RESULTS Benignity and malignancy were accurately diagnosed by both IC and FS. In the borderline group, the diagnostic accuracy of IC was very low (1/6: 16.6%) compared with FS (4/6: 66.6%). The diagnostic accuracy including benign, borderline, and malignant groups was 90.9% (50/55) for IC and 96.3% (53/55) for FS. Concerning the diagnosis of the types of carcinoma, the overall diagnostic accuracy of IC (25/31: 80.6%) was greater than that of FS (21/31: 67.7%), especially for the diagnosis of clear cell carcinoma (IC, 100%; FS, 80%) and mixed carcinoma (IC, 66.6%; FS, 16.6%). CONCLUSION The useful aspects of IC in the intraoperative consultation are the diagnosis of benignity or malignancy and the accuracy of diagnosing clear cell carcinoma and mixed carcinoma.