RESUMO
AIM OF STUDY: To assess the value of intraoperative frozen-section diagnosis in thyroid surgery and determine its limitations. METHODS: This retrospective study examined the results of 1534 frozen sections of thyroid specimens analyzed over the 11-year period from 1995 through 2005 and their correlations with the final histological examination. Deferred responses were not taken into account for statistical calculations. RESULTS: In our series, frozen-section diagnosis was concordant with subsequent histopathological examination in 92% of cases, discordant in 3%, and deferred in 5%. The global specificity of frozen section analysis for all histological subtypes was 99.8% and its sensitivity 67%. Its sensitivity for thyroid cancer was lower in follicular (42%) and papillary carcinoma (64%) than medullary (100%), anaplastic (100%), secondary (100%), mixed (100%), and insular carcinomas (86%). CONCLUSION: In our series, as in the literature, most of the discordances between frozen-section and definitive diagnosis were associated with microfollicular lesions, which explain the low sensitivity of 67%. Our results demonstrate the reliability of intraoperative frozen-section analysis in thyroid surgery. Collaboration between pathologists, radiologists, and clinicians should be emphasized.