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Multiple endocrine neoplasia type 2

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Title: Multiple endocrine neoplasia type 2  
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Multiple endocrine neoplasia type 2

MEN type 2A (Sipple syndrome)
Bilateral pheochromocytomas associated with Multiple endocrine neoplasia type 2
Classification and external resources
ICD-10 D44.8
ICD-9-CM 258.02
OMIM 171400
DiseasesDB 7984
MedlinePlus 000399
eMedicine med/1520
MeSH D018813
GeneReviews
  • Multiple Endocrine Neoplasia Type 2

Multiple endocrine neoplasia type 2 (MEN2) (also known as "Pheochromocytoma and amyloid producing medullary thyroid carcinoma",[1] "PTC syndrome,"[1] and "Sipple syndrome"[1]) is a group of medical disorders associated with

  • MEN2 (RET) gene variant database
  • GeneReview/NIH/UW entry on Multiple Endocrine Neoplasia Type 2
  • The Association for Multiple Endocrine Neoplasia Disorders (AMEND)

External links

  1. ^ a b c Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby.  
  2. ^ Moline J, Eng C. (2011). "Multiple endocrine neoplasia type 2: an overview.". Genet Med. 9 (13): 755–64.  
  3. ^ Thosani S, Ayala-Ramirez M, Palmer L, Hu MI, Rich T, Gagel RF, Cote G, Waguespack SG, Habra MA, Jimenez C (2013) The characterization of pheochromocytoma and its impact on overall survival in Multiple Endocrine Neoplasia type 2. J Clin Endocrinol Metab
  4. ^ Thosani S, Ayala-Ramirez M, Palmer L, Hu MI, Rich T, Gagel RF, Cote G, Waguespack SG, Habra MA, Jimenez C (2013) The characterization of pheochromocytoma and its impact on overall survival in Multiple Endocrine Neoplasia type 2. J Clin Endocrinol Metab
  5. ^ "MEN2 Database". University of Utah. 
  6. ^ Wray CJ, Rich TA, Waguespack SG, Lee JE, Perrier ND, Evans DB (January 2008). "Failure to recognize multiple endocrine neoplasia 2B: more common than we think?". Ann. Surg. Oncol. 15 (1): 293–301.  

References

See also

MEN2B can present with a Marfanoid habitus.[6]

MEN2B is additionally characterized by the presence of mucocutaneous neuroma, gastrointestinal symptoms (e.g. constipation and flatulence), and muscular hypotonia.

MEN2A is additionally characterized by the presence of parathyroid hyperplasia.

As noted, all types of MEN2 include pheochromocytoma and medullary thyroid carcinoma.

Differences in presentation

When inherited, multiple endocrine neoplasia type 2 is transmitted in an autosomal dominant pattern, which means affected people have one affected parent, and possibly-affected siblings and children. Some cases, however, result from spontaneous new mutations in the RET gene. These cases occur in people with no family history of the disorder. In MEN2B, for example, about half of all cases arise as spontaneous new mutations.

Most cases of multiple endocrine neoplasia type 2 are inherited in an autosomal dominant pattern.

Genetics

MEN2 generally results from a gain-of-function variant of a RET gene. Other diseases, such as Hirschsprung disease, result from loss-of-function variants. OMIM #164761 lists the syndromes associated with the RET gene.

The protein produced by the RET gene plays an important role in the TGF-beta (transforming growth factor beta) signaling system. Because the TGF-beta system operates in nervous tissues throughout the body, variations in the RET gene can have effects in nervous tissues throughout the body.

The table in the multiple endocrine neoplasia article lists the genes involved in the various MEN syndromes. Most cases of MEN2 derive from a variation in the RET proto-oncogene, and are specific for cells of neural crest origin. A database of MEN" implicated RET mutations is maintained by the University of Utah Department of Physiology.[5]

Causes

Prognosis of MEN2 is mainly related to the stage-dependant prognosis of MTC indicating the necessity of a complete thyroid surgery for index cases with MTC and the early thyroidectomy for screened at risk subjects.

Familial genetic screening is recommended to identify at risk subjects who will develop the disease, permitting early management by performing prophylactic thyroidectomy, giving them the best chance of cure.

Management of MEN2 patients includes thyroidectomy including cervical central and bilateral lymph nodes dissection for MTC, unilateral adrenalectomy for unilateral pheochromocytoma or bilateral adrenalectomy when both glands are involved and selective resection of pathologic parathyroid glands for primary hyperparathyroidism.

Management

In a review of 85 patients 70 had Men2A and 15 had Men2B.[4] The initial manifestation of MEN2 was medullary thyroid carcinoma in 60% of patients, medullary thyroid carcinoma synchronous with pheochromocytoma in 34% and pheochromocytoma alone in 6%. 72% had bilateral pheochromocytomas.

In familial isolated medullary thyroid carcinoma the other components of the disease are absent.

MEN2B associates medullary thyroid carcinoma with pheochromocytoma in 50% of cases, with marfanoid habitus and with mucosal and digestive neurofibromatosis.

MEN2A associates medullary thyroid carcinoma with pheochromocytoma in about 20–50% of cases and with primary hyperparathyroidism in 5–20% of cases.

In MEN2A primary hyperparathyroidism occurs in only 10–30% and is usually diagnosed after the third decade of life. It can occur in children but this is rare. It may be the sole clinical manifestation of this syndrome but this is unusual.

Pheochromocytoma occurs in 50% of cases.[3]

Medullary thyroid carcinoma (MTC) represent the most frequent initial diagnosis. Occasionally pheochromocytoma and primary hyperparathyroidism may be the initial diagnosis.

MEN2 can present with a sign or symptom related to a tumor or, in the case of multiple endocrine neoplasia type 2b, with characteristic musculoskeletal and/or lip and/or gastrointestinal findings.

Signs and symptoms

The common feature among the three sub-types of MEN2 is a high propensity to develop medullary thyroid carcinoma.

A table in the multiple endocrine neoplasia article compares the various MEN syndromes. MEN2 and MEN1 are distinct conditions, despite their similar names. MEN2 includes MEN2A, MEN2B and familial medullary thyroid cancer (FMTC).

Before gene testing was available, the type and location of tumors determined which type of MEN2 a person had. Gene testing now allows a diagnosis before tumors or symptoms develop.

Classification

Contents

  • Classification 1
  • Signs and symptoms 2
  • Management 3
  • Causes 4
  • Genetics 5
  • Differences in presentation 6
  • See also 7
  • References 8
  • External links 9

MEN2 is a sub-type of MEN (multiple endocrine neoplasia) and itself has sub-types, as discussed below.

[2]

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