Medullary thyroid cancer diagnosis: an appraisal.

Since its first description in 1951, a timely diagnosis of medullary thyroid carcinoma (MTC) may represent a diagnostic challenge in clinical practice. Several contributions have been addressed to the treatment and follow-up of MTC, but review articles focused on the diagnostic problems of this cancer in clinical practice are sparse. As a delayed diagnosis and an inadequate initial treatment may severely affect the prognosis of this thyroid malignancy, the appropriate use and the correct interpretation of the available diagnostic tools for MTC are of crucial importance. The purpose of the present article is to provide an easy-to-use guide reviewing the main issues of MTC diagnosis: (1) basal serum calcitonin; (2) stimulated serum calcitonin; (3) additional serum markers for MTC; (4) ultrasound and other imaging techniques; (5) fine-needle aspiration (FNA) cytology; (6) calcitonin measurement on FNA washout; (7) rearranged during transfection (RET) mutations; and (8) scope of the problem.