Correlation of fine needle aspiration of the thyroid with final histopathology in 198 thyroidectomized patients

Although fine needle aspiration (FNA) has been suggested as choice procedure in pre-operative diagnosis of thyroid nodules، but it may miss a third of all malignancies in palpable nodules of thyroid gland. In a prospective study collected data of 198 consecutive patients who had preoperative FNA، thyroidectomy was performed in a university hospital، were reviewed. The FNA results were classified base on the American Association of Clinical Endocrinologists (AACE) classification. The patients were categorized into benign، malignant and indeterminate groups. The indeterminate group included follicular neoplasms، Hurthle cell lesions، and the follicular variant of papillary thyroid carcinoma (PTC). All FNA results were evaluated by two expert cytopathologists who were blind to the results of histopathology and the clinical features of the patients. A total of 172 (86. 9%) thyroidectomized patients had benign lesions and 36 (13. 1%) had malignant lesions in final histopathology. The most common malignant lesion was PTC (76. 9%. Follicular thyroid carcinoma، medullary thyroid carcinoma and follicular adenoma were found in 3 and 18 patients، respectively. Benign lesions (158 cases، 79. 8%)، malignant lesions (17 cases، 8. 6%)، indeterminate (23 cases، 11. 6%) were reported in FNA. The sensitivity، specificity، positive predictive value، negative predictive value and diagnostic accuracy of FNA were 53. 84%، 98. 01%، 82. 35%، 92. 50، and 81. 81%، respectively. FNA had low sensitivity to detect thyroid malignant lesions preoperatively. Thus، clinical features، findings of thyroid sonography، and novel biological markers should also be considered in the preoperative management of thyroid nodules.