Endocrine Abstracts

Introduction: The first-line investigation of thyroid nodules is ultrasonography. Since the introduction of fine needle aspiration cytology (FNAC) in the last 2 decades, the diagnostic accuracy of thyroid malignancy has massively improved. This study aims to examine the sensitivities of ultrasonography and FNAC respectively, evaluating our centre’s practice.

Methods: Retrospective data were collected from ultrasound scan and FNAC reports of patients who were histologically proved to have thyroid malignancy after thyroidectomy between the period of January 2010 and October 2013 in a major regional endocrine unit in the UK. Ultrasound scan results were categorised into benign, indeterminate and suspicious of malignancy; while FNAC results had five categories including non-diagnostic (Thy1), non-neoplastic (Thy2), follicular (Thy3), suspicious (Thy4) and diagnostic (Thy5). Sensitivities were determined.

Results: 100 patients were histologically diagnosed with thyroid malignancy. 81 patients had both ultrasound scan and FNAC reported. The sensitivity of ultrasonography was 39% (positive if suspicious of malignancy) and that of FNAC was 59% (positive if Thy3, 4 or 5). Of the positive scan results for thyroid malignancy, 66.6% also had a positive FNAC. The average number of months between ultrasound appointment and first thyroidectomy was 2.8.

Conclusions: The combined sensitivity of ultrasonography and FNAC is statistically higher than that of each test on its own in diagnosing thyroid malignancy. Most patients have both tests done especially if there is diagnostic ambiguity on their clinical presentations. Based on the results of this study and recent literatures, FNAC should be readily available at ultrasound appointment to avoid the delay of any surgical management. This study warrants the use of one-stop clinic providing ultrasound-guided FNAC that would not only enhance the diagnostic accuracy but also provide more efficient care for patients presenting with thyroid nodules. Further research is required to investigate the cost-effectiveness of a one-stop clinic.