The impact of nodule size on malignancy risk in indeterminate thyroid nodules

Background: The association between malignancy risk and nodule size in indeterminate thyroid nodules (ITNs) remains controversial. Thus, we aimed to explore the impact of nodule size as a predictor of cancer in patients with ITNs. Methods: This cross-sectional study assessed 113 patients who underwent surgical intervention for ITNs, comparing two groups based on nodule size (>= 4 or <4 cm). The correlation between nodule size and malignancy risk was examined. Other variables of interest included demographics, thyroid-stimulating hormone (TSH) levels, type of surgery, and ultrasound features. Results: Of the 113 patients, 88.5% were aged <55 years, 76.1% were women, and 65.5% had nodules <4 cm. Mean nodule size was 3.4 +/- 2.3 cm. There was no significant correlation between malignancy risk and nodule size (P=0.55). An association was observed between <4 cm nodules and elevated TSH levels (P=0.03) and between >= 4 cm nodules and the presence of hypervascularity (P=0.04). Nodules <4 cm were more likely to have extrathyroidal extension, lymphovascular invasion, and positive margins than those >= 4 cm; however, this was not significant. Conclusions: Our findings showed no association between nodule size and malignancy risk, suggesting that size alone is not a predictor of cancer development. Further prospective studies are required to confirm these results.