[Clinical characteristics of multiple endocrine neoplasia].

Multiple endocrine neoplasia type 1 (MEN1) and type 2 (MEN2) are autosomal dominant inherited multiglandular diseases with familial and individual age-related penetrance and variable expression. The most frequent endocrine features of MEN1 are parathyroid involvement (> 95%), duodeno-pancreatic endocrine tissue involvement (80%), pituitary adenoma (30%), and adrenal cortex tumors (25%), with no clear syndromic variants. Identification of the germline MEN1 mutation confirms the diagnosis, but there is no phenotype-genotype correlation. All patients with MEN2 have medullary thyroid carcinoma (MTC). The most distinctive MEN2 variants are MEN2A (MTC+pheochromocytoma+hyperparathyroidism), MEN2B (MTC+pheo), and isolated familial MTC (FMTC). The prognosis of MEN2 is linked to the progression of MTC, which depends mainly on the stage at diagnosis and the quality of initial surgical treatment. This emphasizes the need for early diagnosis and management. The specific RET codon mutation correlates with the MEN2 syndromic variant and with the age of onset and aggressiveness of MTC. Consequently, RET mutational status should guide major management decisions, such as whether and when to perform thyroidectomy.