Multiple Endocrine Neoplasia
| Definition: |
A group of autosomal dominant, often overlapping diseases characterized by hyperplasia or neoplasia of more than one endocrine gland, many of which are made up of APUD cells. (From Segen, Dictionary of Modern Medicine, 1992) |
| Notes: |
IM; GEN or unspecified; prefer specifics; coord with specific endocrine/neopl precoords (IM) + specific histol type (IM) if pertinent; DF: MULTIPLE ENDOCRINE NEOPL |
Multiple Endocrine Neoplasia Categories.
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Multiple Endocrine Neoplasia Type 1 - A rare syndrome characterized by hyperplasia and/or neoplasms of the pituitary, parathyroid glands, and pancreatic islets. Hyperparathyroidism occurs in 90% of the cases and is usually the first manifestation of the syndrome. The most frequent pancreatic manifestation is gastrinoma typically leading to Zollinger-Ellison Syndrome. The appearance of this condition has been limited to the loss of allelic heterozygosity at the 11q13 locus on the long arm of chromosome 11. Patients overall exhibit long survival times. Chemotherapy is rare and surgical management is generally dependent on the genetic expression in individual patients. (From Holland et al., Cancer Medicine, 3d ed, pp1169-72) |
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Multiple Endocrine Neoplasia Type 2a - A type of multiple endocrine neoplasia characterized by a virtually 100% incidence of medullary thyroid carcinoma, a 50% incidence of pheochromocytoma, and a lesser incidence of parathyroid adenomas associated with hyperparathyroidism. The condition is always transmitted through autosomal dominant inheritance. Genetic testing can identify individuals with the trait in early infancy. Treatment is usually excision of the enlarged parathyroid glands. (From Holland et al., Cancer Medicine, 3d ed, pp1172-75) |
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Multiple Endocrine Neoplasia Type 2b - A type of multiple endocrine neoplasia occurring as an isolated congenital presentation or as a distinct autosomal dominant disease. It is characterized by the 100% incidence of medullary thyroid carcinoma and frequent pheochromocytomas; patients seldom exhibit hyperparathyroidism. It is distinguished from MEN 2a by its characteristic physical appearance resulting from numerous neural defects including mucosal neuromas of the eyelids, lips, and tongue. The neural abnormalities also include widespread neurogangliomatosis of the gastrointestinal tract leading to abnormal gut motility. Treatment usually requires total thyroidectomy following evaluation for the presence of pheochromocytomas. |
Multiple Endocrine Neoplasia Definitions and Terms
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