Abstract
<title>Abstract</title> <p>The differential diagnosis of follicular thyroid carcinoma and benign follicular lesions remains one of the greatest challenges in contemporary thyroid cytopathology. Currently, the diagnosis of follicular thyroid carcinoma is established on the basis of histopathological examination of tissue obtained during surgery. In clinical practice, this leads to procedures that serve both diagnostic and therapeutic purposes. Consequently, patients may be exposed to unnecessary surgical treatment, the risk of perioperative complications, psychological consequences, and the need for lifelong hormone replacement therapy. The aim of this study was to investigate the potential use of the elemental composition of neoplastic lesions as biomarkers for distinguishing follicular thyroid carcinoma from benign lesions. Paraffin-embedded thyroid specimens obtained after total thyroidectomy were analysed, including 15 follicular thyroid cancers and 15 benign nodules. Concentrations of sixteen elements were quantified using triple-quadrupole ICP-MS. Group differences were assessed using the Mann–Whitney U test, and multivariate differentiation was explored using principal component analysis (PCA) and t-distributed stochastic neighbor embedding (t-SNE). Significant differences were observed for iodine, sulfur, phosphorus, vanadium, manganese, and selenium. Benign lesions exhibited markedly higher iodine and sulfur concentrations, whereas follicular thyroid cancer samples showed elevated phosphorus, vanadium, manganese, and selenium. Principal component analysis based on the six discriminating elements achieved complete separation of the groups, which was further confirmed by t-distributed stochastic neighbor embedding clustering. These results demonstrate that multi-elemental profiling provides a robust biochemical framework for distinguishing follicular thyroid cancers from benign follicular lesions and support further evaluation of this approach in cytological material.</p>