Intraoperative Frozen Biopsy for the Evaluation of Extrathyroidal Extension in Papillary Thyroid Cancer

Objectives:We investigated extrathyroidal extension (ETE) through frozen biopsy for intraoperative decision-making in patients with papillary thyroid cancer (PTC).Methods:During the period of the study an operation was performed in 268 patients with PTC and ETE was evaluated using intraoperative frozen biopsies of thyroid tissue.Results:ETE was confirmed in 54 patients (20%) on frozen biopsy. Fifty-three patients among 54 patients showing ETE on frozen biopsy were confirmed on permanent pathologic analysis. Accordingly, frozen biopsy had a sensitivity of 66%, a specificity of 99%, a positive predictive value of 98%, and a negative predictive value of 87%. Tumor size (odds ratio 4.373; confidence interval 2.257-8.475, P < .001) was an independent factor for predicting ETE on frozen biopsy.Conclusions:Intraoperative frozen biopsy can be a useful tool in identifying the presence of ETE. It can also help the operator decide the extent of surgery and central neck dissection in patients with PTC.