Background and aims: Thyroid nodular disease (TND) is a common condition in the general population. Malignant nodules occur in 5% of patients with thyroid nodules. Fine-needle aspiration biopsy (FNAB) is considered to be the most reliable method of differentiating benign and malignant thyroid nodules. The purpose of this study was to assess the accuracy of FNABs performed in our Hospital.
Methods: We retrospectively reviewed the medical records of patients submitted to thyroid surgery in our Hospital between June 1999 and June 2005.
Results: FNABs were performed in our Hospital since 1999. We included in our study 98 patients who had undergone thyroid surgery for TND. To the 98 patients a total of 142 FNABs had been performed. 80% were considered benign, 7% malignant and 13% suspicious. The discrepant cases were: 4 false-negative and 1 false-positive. The 4 false-negative cases had a cytologic diagnosis of nodular hyperplasia and found to be papillary thyroid carcinomas on histologic findings. The false positive case had a cytologic diagnosis of papillary carcinoma that revealed to be an Hürthle cell adenoma on histology. Our results showed a sensitivity of 60% and a specificity of 98.6%.
Discussion: All patients with false-negative results had multiple nodular goitre in which carcinoma was found in non dominant nodules on histology. None of these patients performed FNABs guided by ultrasound, consequently, aspirations were only done on the larger, palpable nodules. We suggest to perform ultrasound-guided FNAB in all supracentimetric nodules, in patients with multinodular goitre.