Are Scintigraphy and Ultrasonography Necessary Before Fine-Needle Aspiration Cytology for Thyroid Nodules?

Abstract

Objective: To evaluate the effi cacy of scintigraphy, ultrasound and fi ne-needle aspiration in thyroid nodules and to establish the best diagnostic pathway in detecting thyroid cancer. Method: Two hundred and sixteen patients with thyroid nodules were examined using high-resolution ultrasonography, 99mTc thyroid scintigraphy and ultrasound-guided fi ne-needle aspiration. Of these, 113 patients subsequently underwent thyroidectomy. The remaining 103 were followed up for two years without any evidence of malignancy. Results: Cytopathology classifi ed 71% of the aspirate as benign, 3% as positive for malignancy, 21% as suspected neoplasia and 5% as unsatisfactory. Fine- needle aspiration cytology had a sensitivity of 87.5% and specifi city of 80%. On ultrasound 33% of malignant nodules were hypo-echoic and on scintigraphy 16% of solitary cold nodules were malignant. Neither test could reliably diagnose thyroid cancer. conclusion: Ultrasound-guided fi ne-needle aspiration cytology should be the fi rst test performed in euthyroid patients with a thyroid nodule. Scintigraphy and ultrasound imaging should be reserved for follow-up studies and patients who have suppressed levels of thyroid stimulating hormone.

Keywords

• thyroid nodule, ultrasonography, thyroid scintigraphy, fine-needle aspiration cytology