Abstract
Medullary thyroid carcinoma is a neuroendocrine tumour of the parafollicular C cells of the thyroid gland. It is an aggressive tumor that can be cured only by complete resection of the thyroid tumour and any local and regional metastases. Thus, the discovery of novel diagnostic and prognostic markers is very important for early diagnosis and correct management, in order for the survival rates to rise. New research has emphasized the potential role of various genes, serum and immunohistochemical markers, as well as potential targets for therapeutic agents. The calcium stimulated calcitonin test has been recently reintroduced in clinical practice, and current medullary thyroid carcinoma guidelines encourage laboratories to set their own criteria defining reference ranges for elevated serum basal and stimulated calcitonin levels.