This book highlights the increase in thyroid tumors and NET and demonstrates the growing importance of circulating markers in diagnosis as well as treatment and follow-up. Dramatic technical improvements have heightened the clinical impact of well-established, conventional biochemical markers. In addition, more recent genetic and molecular approaches have provided innovative molecular markers. In this context, effective communication between clinicians and laboratory physicians/scientists is essential in allowing all those involved to fully profit from these exciting advances.  In this comprehensive, up-to-date book, authors from different laboratory and clinical areas link laboratory and clinical topics. Analytical problems such as interferences, false-negative and false-positive results are discussed in depth, and flow-charts offer insights into identifying and avoiding them. Illustrated clinical cases detail the clinical role and limitations of different tumor markers.