Use of ultrasound-guided fine needle aspiration biopsy in the management of thyroid disease.

Fine-needle aspiration biopsy (FNAB) of thyroid nodules has resulted in fewer patients needing thyroidectomy. Nondiagnostic FNAB specimens may require surgery for diagnosis. Ultrasound can help decrease nondiagnostic biopsies by visualizing lesions and guiding biopsy needles. Between 1996 and 1997, 76 patients had ultrasound-guided needle biopsies of thyroid nodules. Sixteen patients had clearly palpable nodules, whereas 19 were described as difficult to palpate. There were 32 patients who presented with either prominent thyroids or enlarged lobes. Six patients presented only with nonspecific symptoms, and 3 had nodules discovered incidentally on imaging studies. Biopsies were diagnostic in 73 of 76 (96%) patients. This varied with the size of the nodule, with the rate of nondiagnostic biopsies being 13 per cent in lesions <1.0 cm and 3 per cent in lesions >2.0 cm. Fifteen patients had surgery based on the FNAB, with a surgical yield of malignancy of 47 per cent. Ultrasound-guided FNAB is extremely useful in evaluating thyroid lesions that are difficult to palpate or nonpalpable, as well as the remainder of the gland and surrounding structures. The use of ultrasound guidance in performing FNAB results in a low rate of nondiagnostic biopsies, which may decrease the number of unnecessary thyroidectomies performed to rule out malignancy.