Accuracy of intra-operative frozen sections in the diagnosis of ovarian masses.

The accuracy of frozen section diagnosis in the intraoperative evaluation of ovarian masses is very important with regard to surgeon selection of appropriated operating procedures. For evaluation in our institute, the records of 127 patients with ovarian masses submitted for intraoperative frozen sections between January 2001 and December 2005 were reviewed. After exclusion of 4 completely infarcted masses and 11 cases with deferred frozen section diagnoses, 112 were analyzed for diagnostic accuracy by comparing with the final histologic results. We found sensitivity in the diagnosis of benign, borderline and malignant tumors to be 100%, 84%, and 92 %, respectively, with specificities of 92.7%, 97.9%, and 100%, respectively. The overall accuracy with frozen sections was 94 %. Among 18 patients with deferred or discordant diagnoses, mucinous tumors accounted for 72 % of cases. No over-diagnosis of malignancy or misdiagnosis of metastatic lesions as primary ovarian cancer by frozen sections was observed. In conclusion, the accuracy of intraoperative frozen section for the diagnosis of ovarian masses is high. Frozen sections also help in the evaluation of metastatic tumors to the ovary. Mucinous tumors constitute an important group causing diagnostic discrepancies.