Diagnostic Accuracy of Fine Needle Aspiration for Solitary and Multiple Thyroid Nodules in a Tertiary Care Center

Abstract

Background: Thyroid nodules are common in clinical practice. They are usually benign, but malignancy must be ruled out. Fine needle aspiration (FNA) biopsy of the thyroid is a rapid and cost-effective procedure in the initial evaluation of a thyroid nodule, but its results may be inaccurate in 10% to 30% of cases. This prospective observational study was conducted to determine the prevalence of thyroid cancer, its related findings, and the diagnostic accuracy of preoperative FNA in a tertiary care center. Methods: We prospectively studied the medical records of 345 subjects, who underwent thyroid resection in the university hospital setting over a 4-year period. Age, gender, FNA and pathologic reports, and whether the lesion was multinodular or a solitary nodule were determined. Results: The sensitivity and specificity of FNA were 64.96% and 62.76%, respectively. The positive predictive value of the test for the diagnosis of malignant nodules was 59.30% and its negative predictive value was 68.20%. In 63.5% of the patients, the preoperative FNA matched the surgical histopathology results. The presence of multinodular goiter was an important risk factor for thyroid malignancy. Fifty-two subjects had papillary microcarcinoma and the rate of aggressive behavior was considerable in this group. Conclusions: Although fine needle aspiration biopsy is the most important step in the workup of the thyroid nodules, it may miss a significant number of malignant lesions. Therefore, there is a mandatory need to evolve other clinical and laboratory adjuncts, which assists the clinicians with the interpretation of FNA more accurately.