Our aim was to establish the clinical course of euthyroid nodular goiter considering ultrasound stratification tool European Thyroid Imaging Reporting and Data System (EU-TIRADS). Patients diagnosed with euthyroid nodular goiter were invited for re-evaluation 5 years after the diagnosis. Baseline characteristics of the nodules (volume and EU-TIRADS) were retrospectively collected. At follow-up, thyroid ultrasound including nodule volume measurement was performed. One hundred and one patients (92 females and 9 males, mean age 50.4 years, mean TSH 1.52 mIU/L) were included in the study. At baseline, 143 nodules were diagnosed with the mean volume 1.2 mL. Regarding EU-TIRADS, 36.4% of nodules were categorized as EU-TIRADS 2, 37.1% as EU-TIRADS 3, 22.4% as EU-TIRADS 4 and 1.4% as EU-TIRADS 5. After 5 years, the mean volume of the nodules significantly increased to 1.8 mL (p(0.001). In EU-TIRADS 3, the mean increase of nodule volume was 1.2 mL, in EU-TIRADS 4, 0.9 mL, and in EU-TIRADS 2, a decrease in nodule volume of -0.03 mL was observed. The absolute change in nodule volume differed significantly between EU-TIRADS groups when compared pairwise (between EU-TIRADS 2 and 3, p(0.001, between EU-TIRADS 2 and 4, p(0.05, and between EU-TIRADS 3 and 4, p(0.001, respectively). Our results show that nodules with ultrasound morphological characteristics classified as EU-TIRADS 3, although benign, have the largest growth potential, while nodules classified as EU-TIRADS 2, tend to decrease in size. Further research should evaluate if there is an increased need for clinical management of EU-TIRADS 3 subgroup of euthyroid nodular goiter patients.
COBISS.SI-ID: 6492332