Background: Fine-needle aspiration biopsy is the gold standard in the preoperative management of thyroid nodules.
Aim: The aim of this study was to investigate whether serum TSH is a predictor of thyroid malignancy in patients presenting with thyroid nodules.
Subjects and methods: About 565 patients without overt thyroid dysfunction, who presented with palpable thyroid nodule(s) between 1988 and 2004 and underwent at least one FNAB, were retrospectively evaluated.
Results: The final diagnostic outcome was established after surgery (n=122) or after a minimum of one-year clinical follow-up period. Higher rates of malignancy were observed in patients with serum TSH in the upper tertile of the normal range (P=0.026). Binary logistic regression analysis revealed significantly increased adjusted odds ratios for the diagnosis of malignancy in patients with serum TSH 1.54.0 mIU/l compared to those with either TSH 0.40.8 mIU/l (P=0.005) or TSH 0.91.4 mIU/l (P=0.007).
Conclusions: The risk of malignancy in thyroid nodules increases in parallel with TSH concentrations within the normal range. TSH concentration at presentation is an independent predictor of thyroid malignancy.