Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed. A multiple endocrine neoplasia, a polyglandular cancer syndrome. The clinical manifestations of MEN2 are related to the syndrome subtypes and depend on the specific mutation in the RET gene. Other features of MEN2B include multiple neuromas of the gastro-enteric mucosa, bumps on the lips, eyelids, and tongue, hyperextensible joints and marphanoid habitus.
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Multiple endocrine neoplasia, type 2B MEN 2B is an autosomal dominant syndrome characterized by medullary thyroid carcinoma, pheochromocytoma, multiple mucosal neuromas and intestinal ganglioneuromas, and often a marfanoid habitus and other skeletal abnormalities.
Symptoms depend on the glandular elements present. Diagnosis and treatment are the same as for MEN 2A. See also Overview of Multiple Endocrine Neoplasias.
As in MEN 2A and familial medullary thyroid carcinoma , this mutation results in activation of RET proto-oncogene—mediated cellular processes. Symptoms and signs reflect the glandular abnormalities present see table Conditions Associated With Multiple Endocrine Neoplasia Syndromes. Often, mucosal neuromas are the earliest sign, and they occur in most or all patients. Neuromas appear as small glistening bumps on the lips, tongue, and buccal mucosae.
The eyelids, conjunctivae, and corneas also commonly develop neuromas; infants are often unable to make tears. Thickened eyelids and everted, diffusely hypertrophied lips are characteristic. Gastrointestinal abnormalities related to altered motility constipation, diarrhea, and, occasionally, megacolon are common and thought to result from diffuse intestinal ganglioneuromatosis.
Patients almost always have a marfanoid habitus. Skeletal abnormalities are common, including deformities of the spine lordosis, kyphosis, scoliosis , slipped capital femoral epiphyses, dolichocephaly hull-shaped skull, also called scaphocephaly , pes cavus, and talipes equinovarus.
Medullary thyroid carcinoma and pheochromocytoma resemble the corresponding disorders in MEN 2A syndrome; both tend to be bilateral and multicentric. Medullary thyroid carcinoma, however, tends to be particularly aggressive in MEN 2B and may be present in very young children.
Although the neuromas, facial characteristics, and gastrointestinal disorders are present at an early age, the syndrome may not be recognized until medullary thyroid carcinoma or pheochromocytoma manifests in later life. MEN 2B is suspected in patients with a family history of MEN 2B, pheochromocytoma, multiple mucosal neuromas, or medullary thyroid carcinoma. Genetic testing is highly accurate and is done to confirm the disorder. Pheochromocytoma may be suspected clinically and is confirmed by measuring plasma free metanephrines and urinary catecholamines.
Laboratory testing for medullary thyroid carcinoma may be done. MRI or CT is used to search for pheochromocytomas and medullary thyroid carcinoma. Affected patients should have total thyroidectomy as soon as the diagnosis is established. Pheochromocytoma, if present, should be removed before thyroidectomy is done. Multiple endocrine neoplasia, type 2B MEN 2B has a mutation of the same gene as in MEN 2A and manifests similarly except for the absence of hyperparathyroidism, the presence of more aggressive medullary thyroid carcinoma and the presence of multiple mucosal neuromas and a marfanoid habitus.
Patients should have genetic testing for RET proto-oncogene mutations and blood or urine tests for pheochromocytoma. From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world.
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Multiple endocrine neoplasia
NCBI Bookshelf. Additional features in MEN 2B include mucosal neuromas of the lips and tongue, distinctive facies with enlarged lips, ganglioneuromatosis of the gastrointestinal tract, and a marfanoid habitus. The diagnosis of MEN 2 is established in a proband who fulfills existing clinical diagnostic criteria. Molecular genetic testing to identify a heterozygous germline RET pathogenic variant is indicated in all individuals with a diagnosis of primary C-cell hyperplasia or MTC or a clinical diagnosis of MEN 2.
Multiple Endocrine Neoplasia, Type 2B (MEN 2B)
Multiple endocrine neoplasia, type 2B MEN 2B is an autosomal dominant syndrome characterized by medullary thyroid carcinoma, pheochromocytoma, multiple mucosal neuromas and intestinal ganglioneuromas, and often a marfanoid habitus and other skeletal abnormalities. Symptoms depend on the glandular elements present. Diagnosis and treatment are the same as for MEN 2A. See also Overview of Multiple Endocrine Neoplasias.