Abstract
Background: Multiple endocrine neoplasia type 2B (MEN 2B) is mainly caused by M918T RET germline mutation, and characterized by medullary thyroid carcinoma (MTC), pheochromocytoma (PHEO) and non-endocrine features. However, the diagnosis and treatment are usually delayed.
Methods: This study reports 5 Chinese pedigrees with 5 individuals harboring germline RETM918T, and systematically reviewed previous Chinese literature reported.
Results: All 5 patients initially presented MTC, but none had biochemically cured postoperatively. 2 also presented bilateral PHEO after adrenal-sparing surgery, 1 needed steroid replacement. Further, a total of 32 MEN 2B patients from literature were clustered with 28 available for analysis. 26 (92.8%) were diagnosed by endocrine-related symptoms; the remaining 2 (7.2%) due to RET testing and oral symptoms, respectively. 25 patients underwent thyroidectomy with/without neck lymph node dissection at the mean age of (23.3 ± 10.4) years. Histopathological examination revealed MTC (100%). Of them, 17 had definite TNM stage, with 1 in stage III and others in IV. Other information of MEN 2B-related symptoms included penetrance of PHEO (60.7%), constipation (32.1%), Hirschsprung disease (25%), alacrima (17.8%), mucosal ganglioneuroma (96.4%) and marfanoid habitus (71.4%). 19 patients were verified harboring RET-M918T (c.2753T>C), of whom 15 (78.9%) were de novo mutation. The other 9 were clinically diagnosed as MEN 2B.
Discussion & Conclusion: The initial diagnosis of MEN 2B is relatively later, and diagnosed by non-endocrine components is extremely lower. Recognition of MEN 2B and its non-endocrine-related components is still the utmost requirement for a Chinese physician. Combined RET screening and serum calcitonin detection can facilitate early diagnosis.
Keywords: Multiple endocrine neoplasia type 2B, medullary thyroid carcinoma, extra-endocrine signs, RET proto-oncogene, M918T mutation, Chinese.
Graphical Abstract
[http://dx.doi.org/10.1038/363458a0] [PMID: 8099202]
[http://dx.doi.org/10.1007/s00259-016-3404-7] [PMID: 27118126]
[http://dx.doi.org/10.1089/thy.2014.0335] [PMID: 25810047]
[http://dx.doi.org/10.1093/hmg/3.2.237] [PMID: 7911697]
[http://dx.doi.org/10.1530/ERC-17-0209] [PMID: 28698189]
[http://dx.doi.org/10.1530/ERC-17-0335] [PMID: 29066504]
[http://dx.doi.org/10.1530/ERC-17-0325] [PMID: 29142004]
[http://dx.doi.org/10.1001/jama.1996.03540190047028] [PMID: 8918855]
[http://dx.doi.org/10.1089/thy.2010.0328] [PMID: 21186952]
[http://dx.doi.org/10.1530/EC-18-0220] [PMID: 30300539]
[http://dx.doi.org/10.1097/SLA.0b013e3182a6f43a] [PMID: 23979292]
[http://dx.doi.org/10.1080/07357907.2018.1430813] [PMID: 29420094]
[http://dx.doi.org/10.4158/EP171875.OR] [PMID: 28613942]
[http://dx.doi.org/10.4158/EP12430.RA]
[http://dx.doi.org/10.1210/jc.2018-00705] [PMID: 30113649]
[http://dx.doi.org/10.1016/S2213-8587(18)30336-X] [PMID: 30660595]
[http://dx.doi.org/10.1210/jc.2017-01884] [PMID: 29077903]
[http://dx.doi.org/10.3389/fonc.2017.00238] [PMID: 29057215]
[http://dx.doi.org/10.1016/S1470-2045(14)70154-8] [PMID: 24745698]
[http://dx.doi.org/10.1210/jc.2014-1498] [PMID: 24893135]
[http://dx.doi.org/10.1530/ERC-17-0202] [PMID: 28883084]
[http://dx.doi.org/10.1210/jc.2013-1653] [PMID: 24030942]
[http://dx.doi.org/10.1515/jpem.2011.262] [PMID: 21932595]
[http://dx.doi.org/10.1089/thy.2016.0148] [PMID: 28276947]