Differentiation between Thyroidal and Ectopic Calcitonin Secretion in patients with Coincidental Thyroid Nodules and Pancreatic Tumors – A Report of Two Cases - Schneider, R.; Heverhagen, A. E.; Moll, R.; Bartsch, D. K.; Schlosser, K. (Experimental and Clinical Endocrinology & Diabetes, 2010)