[The treatment of medullary thyroid cancer].

Medullary thyroid cancer( MTC) is a neuroendocrine tumor arising from neural-crest-derived, calcitonin-secreting parafollicular C cells within the thyroid. Serum calcitonin (CT) is the most specific and sensitive marker for MTC for both the primary diagnosis and postsurgical follow-up. MTC may occur either sporadically or as part of a hereditary disease such as multiple endocrine neoplasia Type 2A (MEN 2A), multiple endocrine neoplasia Type 2B (MEN 2B) or familial medullary thyroid cancer(FMTC). The primary treatment of MTC is surgical removal of all neoplastic tissue present in the neck and lymph nodes; this should be performed after the careful exclusion of a phenochromocytoma. Mutations in the RET gene are associated with MEN2A, MEN2B and FMTC. Specific RET mutations are associated with each of the MEN2 syndromes and with the aggressiveness of MTC. Consequently, the nature of the RET mutation should guide major management decisions and inform the treatment strategy for MTC.