1. Department of Internal Medicine, Azienda Ospedaliero-Universitaria di Perugia, Perugia, Italy;
2. Studio Tiroide Prof. De Feo, Perugia, Italy;
3. Institute of Pathological Anatomy, Azienda Ospedaliero-Universitaria di Perugia, Perugia, Italy;
4. Department of Endocrine Surgery, Azienda Ospedaliero-Universitaria di Perugia, Perugia, Italy;
5. Department of Endocrine Surgery, Azienda Ospedaliero-Universitaria di Terni, Perugia, Italy