AIMS:   Thyroid fine-needle biopsy (FNB) is a simple, reliable, inexpensive and generally safe diagnostic procedure in the management of thyroid nodules. FNB may trigger biochemical alterations through destruction of thyroid follicles. We aimed to investigate long-term post-FNB alterations in serum thyroid-related parameters.
METHODS:   One hundred and ten consecutive patients with thyroid nodular disease were subjected to FNB. Thyroid stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3), thyroglobulin (Tg), thyroglobulin autoantibodies (anti-Tg), thyroid-peroxidase autoantibodies (anti-TPO) were measured in all subjects at baseline, 10 days, 2 and 6 months. Subsequently, patients were divided into subgroups according to the technique of FNB, the presence of disease characteristics as thyroid autoimmunity (Hashimoto's thyroiditis), goitre, singularity-maximum diameter-blood pattern of the nodule(-s), the number of passes and the administration of L-thyroxine (LT4).
RESULTS: A significant increase in Tg, anti-Tg and FT3 levels was observed. These alterations were more prominent within patients with dominant nodule's maximum diameter ≥ 2 cm or without Hashimoto's thyroiditis. Tg and anti-Tg levels were significantly increased only in patients not being on LT4. On the other hand, FNB technique did not affect any of the measured parameters.
CONCLUSION: Our data suggest that FNB results in statistically significant but clinically insignificant increases in Tg, anti-Tg and FT3 levels, implying a thyroid trauma of some level, more likely to happen in patients with larger nodules. The FNB technique used has no effect on the thyroid-related biochemical parameters.