Significance of nondiagnostic fine-needle aspiration of the thyroid

BACKGROUND: Fine-needle aspiration biopsy (FNAB) has been shown to be rapid and cost effective in the evaluation of thyroid nodules. The significance of nondiagnostic (unsatisfactory) FNAB is uncertain, however. METHODS: We reviewed 345 consecutive thyroid FNABs and identified 59 patients with initially unsatisfactory specimens. These patients had follow-up to determine whether their thyroid nodules proved to be malignant. RESULTS: Three patients (5.1%) were found to have organ-confined papillary carcinoma of the thyroid, the largest tumor mass measuring 1.2 cm. Six patients (10.2%) had benign adenomas. CONCLUSIONS: In most cases of initially nondiagnostic FNAB of a thyroid nodule, neoplasia is not found subsequently. A minority of cases may still harbor malignancy. None of our patients in whom repeated FNA was either nondiagnostic or suggestive of benign disease were ultimately found to have a malignancy.