The effects of fine-needle biopsy on thyroid hormone levels

OBJECTIVE: Our study aim was to investigate the effects of fine-needle biopsy used for thyroid nodules on serum thyroid hormone levels. STUDY DESIGN: A total of 25 patients who had solid nodules of the thyroid gland and normal thyroid hormone levels underwent diagnostic fine-needle biopsy for a nodule of the thyroid gland. METHODS: Venous blood samples were drawn from the cases for measurement of serum total T(3) and T(4), free T(3) and T(4), thyroid-stimulating hormone, and thyroglobulin levels before, immediately after, and 30 minutes after the initial biopsy. RESULTS: Total T(3) and thyroglobulin levels were found to be significantly higher immediately and 30 minutes following fine-needle aspiration biopsy, compared to the baseline levels (P<0.05). CONCLUSION: Preliminary data suggest that thyroid hormone levels show a mean increase of about 20% immediately after fine-needle aspiration. SIGNIFICANCE: The implication of this finding on patient care should be determined on an individual basis.