Ancillary molecular testing of indeterminate thyroid nodules

Cytological specimens from thyroid nodules are increasingly being adopted as the first available material for cost effectively managing patients in the era of personalized medicine. Cytology aspirates not only play a central role in providing accurate diagnoses, but are also being collected for ancillary molecular testing. Molecular analysis, including the evaluation of somatic mutations and other genomic alterations, has accordingly become well integrated in the cytological workup of thyroid lesions. Appropriately handled thyroid cytology preparations provide well-preserved and adequately cellular material with improved DNA/RNA quantity. The recent publication of the 2nd edition of The Bethesda System for Reporting Thyroid Cytopathology and the American Thyroid Association guidelines confirm the relevant role of molecular testing in the management of the different subcategories of indeterminate thyroid lesions. This review discusses the role of molecular testing for indeterminate thyroid nodules, including the recent introduction of the noninvasive, encapsulated follicular variant of papillary thyroid carcinoma (FVPTC), known also as noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP).