Metabolomics approach to thyroid nodules: A high-resolution magic-angle spinning nuclear magnetic resonance-based study

Background: Proton magnetic resonance spectroscopy of operative specimens has been reported to successfully differentiate normal tissue from malignant thyroid tissue. We used a new high-resolution magnetic resonance spectroscopy technique for the differentiation of benign and malignant thyroid neoplasms. Methods: Histological specimens from 72 patients undergoing a total thyroidectomy were processed into a 4-mm ZrO₂ high-resolution magic angle spinning (HRMAS) rotor with 5 μL of D₂O. A Bruker Avance spectrometer operating at 400 MHz for the ¹H frequency and equipped with a ¹H/¹³C/³¹P HRMAS probe was used. Results: Normal and neoplastic thyroid tissues could be discriminated from each other by different relative concentrations of several amino acids and lipids, as well as benign and malignant neoplasms, that differed in terms of a greater lactate and taurine and a lesser lipid choline, phosphocholine, myo-inositol, and scyllo-inositol levels in malignant samples. A statistical analysis with a receiver operating characteristic curve revealed that 77% of the samples were accurately predicted. Similar results were obtained with specimens obtained from ex vivo aspirates. Conclusion: A further development of this project will be to use the metabolomics approach on specimens obtained from aspirates in vivo after the resolution of technical problems attributable to possible contamination.