Introduction: Ultrasonography-guided fine-needle aspiration biopsy (ug-FNAB) is recommended as the first and most important step in the management of nodular thyroid disease.
Material and methods: We compared the results of ultrasonography examination (US) and the ug-FNAB of the thyroid gland with postoperative histpathological findings in 387 patients with thyroidectomy operated on (61 cytological and 326 clinical indication).
Results: Cytological diagnoses included 298 benign nodules (BN) (77%), 40 suspicious of follicular (FN) or 16 of Hurthle cell neoplasm (HCN), 21 papillary carcinoma and 8cysts.The incidence of thyroid carcinomas in the population studied was 8.5%. The size of the nodule was not related to the probability of getting an adequate specimen for cytological diagnosis. All patients were divided into four groups. Group I subjects with BN-97.8% were confirmed on histological results, whereas 6 of them were malignant (4 papillary, 1 follicular, 1 Hurthle cell). Group II histological confirmation of malignancy was 8 (20%) out of 40 patients with a diagnosis of FN (5 follicular, 3 papillary carcinoma). In this group we found also 17 follicular adenoma and 15benign nodules. Group III in the ug-FNAB diagnosed group of HCN after histological verification were 18.7% of carcinoma. GroupIV-in the 21 patients with diagnosis of papillary carcinoma, 16 cases were confirmed, 1 was FN and 4 benign. Correlation of cytology and histology showed that 76.2% ug-FNAB results correlated with the histological diagnoses, whereas 23.8% was discrepant. The smallest papillary carcinoma diagnosed by ug-FNAB had a diameter of 0.4 cm and 30% of all papillary cancer <1 cm displayed stage pT4.
Conclusion: Nodules with non-suspicious ug-FNAB results can be safety followed-up by US and ug-FNAB. However, FN and HCN remain the limitation of ug-FNAB, as the cytology cannot distinguish between benign and malignant nodules. Clinical characteristics, such as gender, age and nodule size, are not useful predictors for the presence of malignancy.