Comparision of preoperative and postoperative histopathology findings in patients undergoing thyroidectomy

Abstract

To compare the histopathological findings on fine needle aspiration (FNA) biopsy of thyroid nodules and thyroidectomy surgical specimens, in order to determine the efficacy, specificity and sensitivity of FNA in the diagnosis of thyroid malignancy. The data on a series of 86 patients who underwent thyroidectomy for thyroid nodules were evaluated retrospectively. The demographic characteristics and imaging findings were reviewed, and the histopathological findings on the preoperative FNA biopsy and the surgical thyroid specimen were compared. The FNA findings on the thyroid nodules were: 32.1% benign, 12.2% malignant, 2.7% suspicion of malignancy, 6% atypia of undetermined significance, 15.7% follicular lesion and/or suspicion of follicular neoplasm, and in 31.3% the aspirate was inadequate. The postoperative histopathological specimens were evaluated as 31 malignant (36%) and 55 benign (64%). Statistically significant correlation was demonstrated between the FNA and the postoperative histopathological findings (p<0.05). In this series, the overall sensitivity of FNA biopsy was 10%, the specificity 70.9%, the positive predictive value 16% and the negative predictive value 58%. This study identified a high negative predictive value of FNA biopsy, and an increased rate of “nondiagnostic” and “microcarcinoma” outcomes, but the sensitivity of FNA in the preoperative diagnosis of thyroid malignancy was low.