Several classification systems of thyroid FNA categories have been published during the last two decades. These different systems aim to provide cytopathologists and clinicians with guidelines for the stratification of the risk of malignancy (RoM) of cytologic specimens, but they cannot be perfectly compared. Each system was elaborated in dissimilar regional contexts with specific local settings (culture and practice of the operating cytopathologists/endocrinologists/surgeons, socioeconomic contexts, healthcare systems, and patients’ ethnicity), and each of them employs a different terminology, and, most importantly, has a specific intent.