The results of ultrasound-guided fine-needle aspiration biopsy for evaluation of nodular thyroid disease

Background. The purpose of this study was to determine whether ultrasonography (US) improves the accuracy and reduces the rate of nondiagnostic fine-needle aspiration biopsy (FNAB) of thyroid nodules. Methods. A review of 536 consecutive patients evaluated for nodular thyroid disease, from 1990 to 2001 was completed to determine the results for US vs palpation-guided FNAB. Results. FNAB was used to evaluate 458 patients. US-guided FNAB was performed in 66 (12%) patients: 48 with a nonpalpable nodule, 14 with nondiagnostic standard and 4 with a palpable nodule. US-guided FNAB was nondiagnostic in 15 (23%) patients. There were no false-positive or false-negative results. Standard FNAB was performed in 407 patients, 57 (14%) of whom had a non-diagnostic result. There were 2 (3%) false-positive and 3 (1.6%) false-negative results. In 14 patients with a nondiagnostic standard FNAB, US-guided FNAB yielded an adequate specimen in 7 (50%). Nodules evaluated by standard FNAB were 4.1 +/- 0.1 cm (mean +/- SEM) in size command with 2.5 +/- 0.1 cm for nodules evaluated by US-guided FNAB (P < .05). Conclusions. US improves the diagnostic Yield in selected patients with nondiagnostic standard FNAB. The higher frequency of nondiagnostic US-guided FNAB was related to its selective use in patients with smaller nodules.