Endocrine Abstracts

Introduction: Thyroid nodules are commonly encountered in clinical practice, the main diagnostic problem being the benign or malignant nature of the nodules. Fine-needle aspiration biopsy (FNAB) is a standard diagnostic test for evaluating thyroid nodules. Several studies have showed that the use of ultrasound guidance (US-FNAB) improves the diagnostic accuracy of aspiration biopsies in comparison with palpation guidance (P-FNAB) alone.

Patients and methods: We performed a retrospective study to compare the efficacy of US-FNAB of thyroid nodules with that of P-FNAB. Study group included patients referred to Endocrinology Department for assessment of thyroid nodular disease who underent FNAB by palpation from 2000 to 2001 and under echoguidance in 2009–2012. In order to avoid differences due to nodules size we have selected only palpable nodules in both groups. Thyroid examinations, ultrasound imaging, and aspiration biopsies were performed by the same endocrinologist. Histopathologic and cytologic diagnoses were compared for patients who were operated.

Results: Study sample consisted of 403 patients. P-FNAB was performed in 106 patients (of which 32 underwent thyroidectomy), and US-FNAB in 297 patients (58 operated). Excepting for moderate local pain in some cases, no adverse effects were noticed. Cytologic diagnostic accuracy rate was 83.87 and 90.19% for P-FNAB and US-FNAB respectively. With use of ultrasound guidance, sensitivity (85.71% for US-FNAB and 50% for P-FNAB), positive predictive value (60% vs 40%), and negative predictive value (97.56% vs 92.3%) were increased significantly and the false-negative rate was significantly reduced (14.28% vs 50%).

Conclusions: FNAB is an essential diagnostic tool in the management of thyroid nodules. US-FNAB improved the cytologic diagnostic accuracy, sensitivity, and positive predictive value and reduced the false-negative rate in comparison with P-FNAB. Therefore, practice guidelines should universally recommend US-FNAB in the management of thyroid nodules, permitting an accurate preoperatory diagnostic and avoiding numerous unnecessary surgical interventions.