Combining the American Thyroid Association's Ultrasound Classification with Cytological Subcategorization Improves the Assessment of Malignancy Risk in Indeterminate Thyroid Nodules.

The risk of malignancy (RoM) of indeterminate thyroid nodules (ITNs) shows a high variability in interinstitutional cohorts. The RoM is partially associated with the cytological degree of atypia and the ultrasound (US) pattern. This study evaluated the cancer risk of ITNs by jointly considering the cytological subcategory and the American Thyroid Association (ATA)-based US risk classification.