The efficacy of fine-needle aspiration (FNA) biopsy and its role in the management of a nodular goiter are clearly established. The accuracy of cytologic diagnosis approaches 95%.

FNA biopsy is a reasonable approach to thyroid nodules; it has decreased costs substantially because it facilitates selection of patients who need to undergo surgical excision. Selecting patients for operation on the basis of results of FNA biopsy has more than doubled the yield of carcinoma. The limitations of cytologic examination, nondiagnostic results, and cellular follicular neoplasms should be remembered but need not negate continued use of FNA biopsy. Negative (benign) and positive (malignant) cytologic results are conclusive; careful clinical follow-up of benign nodules and surgical excision of malignant nodules are recommended. Nondiagnostic results are inconclusive; further evaluation by repeated FNA biopsy, ultrasound-guided biopsy, or radionuclide scanning is necessary. Suspicious cytologic results are also inconclusive and are associated with a 20% chance of malignant involvement; surgical treatment is necessary for clarification. The role of levothyroxine therapy remains uncertain and is not recommended until compelling data are available.

FNA biopsy is a safe, simple, reliable, and cost-effective means of detecting benign nodules. FNA biopsy, not thyroid scanning or ultrasonography, is the preferred initial diagnostic test in all patients with thyroid nodules.