About one quarter of MTC cases are inherited as familial syndrome or as a component of the multiple endocrine neoplasia 2 (MEN2) syndromes caused by activating germline mutations of the Rearranged during Transfection (RET) proto-oncogene, and the rest arise spontaneously and sporadically [3, 4]. Here, RET is linked to medullary thyroid gland carcinoma.