Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + • Family of syndromes including: -MEN 2A (Sipple syndrome)-MEN 2B-Familial medullary thyroid carcinoma (FMTC)• MEN 2A is characterized by: -Medullary thyroid carcinoma (MTC)-Pheochromocytomas-Parathyroid hyperplasia• MEN 2B consist of MTC, pheochromocytoma, mucosal neuromas, gangliomatosis of the GI tract, and a distinctive marfinoid habitus-Also have high incidence of skeletal abnormalities, such as congenital dislocation of the hip, pes planus or cavus, kyphosis, and pectus excavatum• Transmitted as mendelian autosomal trait, but can occur de novo (especially MEN 2B)• Common mutation is in the Ret proto-oncogone (tyrosine kinase), which maps to the centromeric region of chromosome 10• Families with hereditary MTC need to be identified with an aggressive screening program because early diagnosis and thyroidectomy renders MTC curable in a large percentage of patients +++ Epidemiology + • MEN 2A and 2B are transmitted with 100% penetrance but variable expressivity• Nearly every affected person with MEN 2A and 2B develop bilateral, multicentric MTC• Pheochromocytomas are present in 50% of MEN 2A patients• Parathyroid hyperplasia is present in 25% of MEN 2A patients• MTC occurs earlier and is more aggressive in patients with MEN 2B than those with MEN 2A• 20% of MTC occurs in a familial setting• Peak incidence of MTC in setting of FMTC, MEN 2A, or MEN 2B is second or third decade of life• Pheochromocytomas appear in second or third decade of life; 60% are bilateral +++ Symptoms and Signs + • Diarrhea• Palpable thyroid nodule, or multinodular thyroid gland• Enlarged, firm cervical nodes (if metastatic disease)• Hoarseness, dysphagia +++ Laboratory Findings + • Calcitonin level is elevated (either basally, or after stimulation with calcium and pentagastrin)• Elevated plasma metanephrines; elevated urinary catecholamines• Elevated serum calcium and intact parathyroid hormone +++ Imaging Findings + • Neck x-rays: May show irregular, dense calcifications• Chest film: May show calcified metastatic hilar and mediastinal nodes• Abdominal CT scan: Can demonstrate adrenal masses• MIBG scan: Can localize pheochromocytomas + • MTC is usually the first abnormality expressed in MEN 2A and 2B• Pheochromocytomas are nearly always limited to the adrenal medulla and are nearly always benign• Most patients are asymptomatic with respect to parathyroid disease• Pheochromocytoma should be excluded prior to operative neck exploration• Genetic testing is available for Ret mutations + • Complete history (including family) and physical exam• Serum calcitonin, calcium, parathyroid hormone, metanephrine levels• Genetic screening for all patients with MTC +++ Surgery +++ Indications + • Elevation of calcitonin level or as soon as diagnosis of FMTC, MEN 2A, or MEN 2B is made• Presence of pheochromocytoma• Hypercalcemia +++ Treatment Monitoring + • Calcitonin level• Routine radiologic and ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free a profile for additional features.