It accounts for up to 1% to 2% of all thyroid cancers and includes both sporadic and familial forms.1 The inherited cases are typically associated with germ-line mutations in the RET proto-oncogene, and may coexist with other neoplasia as part of the multiple endocrine neoplasia type 2 (MEN2) familial syndromes. This evidence concerns the gene RET and multiple endocrine neoplasia type 2.