Abstract
One of the most discussed and controversial issue in the management of thyroid nodules is the need to perform a routine measurement of serum Calcitonin (Ct) in all cases. The American Thyroid Association guidelines do not recommend in favor or against this procedure since they retain that there are not enough evidences that it can determine an advantage to the health outcomes of these patients. This is not the view of many European experts who met in Lisbon in 2009 at the European Thyroid Association-Cancer Research Network meeting to discuss all the still open controversial issues on the management of medullary thyroid cancer patients.This paper is focused on the routine measurement of serum Ct in all patients with thyroid nodule(s): the evidences, the rational and the benefits of this procedure are deeply analysed following the discussion that was done in Lisbon. The conclusions reached at that time are reported in detail.