Accuracy and Significance of Fine-Needle Aspiration Cytology and Frozen Section in Thyroid Surgery.

OBJECTIVE: In the retrospective study to review the records of patients who had undergone thyroid surgery between 1986-1995 and to determine the need of frozen section (FS) following FNA biopsy. METHODS: The records of 2083 patients who had thyroid surgery in Gazi University Medical Faculty Department of General Surgery between 1986-1995 were retrospectively reviewed to determine and compare the accuracy and significance of fine-needle aspiration (FNA) cytology and intraoperative frozen section (FS). Results. In 61 patients, both FNA and FS diagnosis were available for the comparison with the final pathologic diagnosis. In 196 patients, FNA diagnosis was available for the comparison with the final pathological diagnosis by permanent section and in 377 patients FS diagnosis was available for the comparison with the final pathological diagnosis. The sensitivity value for detection of malignancy by means of FNA was 57.1 % compared to 82.2 % by means of FS, and FS diagnosis was more specific (99 %) than FNA diagnosis (90.9 %). FNA diagnosis of benign conditions was correct in 141 of 150 (94 %) patients. FS diagnosis of benign conditions was correct in 313 of 321 (97.5 %) patients. Nine patients had the FNA findings that were positive for malignancy and FS confirmed this diagnosis in 8 patients. Conclusions. FNA is an important diagnostic tool for eliminating benign nodules, but it is not perfect. FS is very important for determining the surgical procedure, and because of direct observation of suspicious nodule, it is even more accurate. Using these tools together is more reliable, since the number of false positive and false negative values is lower than if only the individuals methods are used.