Fine-needle aspiration. Usefulness for diagnosis and management of metastatic carcinoma to the thyroid.

The usefulness of fine-needle aspiration (FNA) for the diagnosis and management of metastatic carcinoma to the thyroid was determined by reviewing the records of 19 patients identified during a six-year period. Fine-needle aspiration was able to document metastatic cancer to the thyroid in 14 patients with, and five patients without a history of prior nonthyroidal cancer. Breast, kidney, and lung were the most frequent carcinomas metastatic to the thyroid. Age range and time from diagnosis of the primary carcinoma to documentation of metastasis were similar to those in prior surgical series from this institution. The finding of metastatic disease on FNA was totally unexpected in four patients. The possibility of metastasis was not mentioned before FNA in six patients with a known history of nonthyroidal cancer. Only six patients underwent a thyroid operation after FNA. Fine-needle aspiration was able to direct appropriate surgical or conservative management without adversely affecting survival among patients.