DTC has a generally favorable prognosis. The possibility to discriminate between patients with aggressive tumors and those with a more indolent behavior may reduce the need for unnecessary treatments. Aim of this observational study is to evaluate how anamnestic, clinical, and histopathological variables may influence the outcome of the enrolled patients, both regarding morbidity and mortality and in terms of therapeutic choices. The study aims to evaluate the prognostic impact of the therapeutic interventions in terms of efficacy and regarding the appearance of adverse events.