Mutational analysis of the RET proto-oncogene in a kindred with multiple endocrine neoplasia type 2A and Hirschsprung's disease.

BACKGROUND/PURPOSE: Germline mutations of the RET proto-oncogene (RET; 10q11.2) have been reported in multiple endocrine neoplasia type 2A (MEN 2A) and Hirschsprung's disease. The authors investigated a Japanese kindred in which MEN 2A and Hirschsprung's disease frequently have been found. METHODS: The pedigree consisted of 28 members (11 boys and 17 girls) spanning 4 generations, of whom, 8 were affected with MEN 2A or Hirschsprung's disease. RESULTS: Direct sequence DNA analysis of the RET proto-oncogene showed a heterozygosity for a G to C transition at the second nucleotide of codon 620 (exon 10) in the patients, resulting in the replacement of cysteine by a serine residue in the affected Ret protein. This family added a novel RET missense mutation (C620S) predisposing to the association of MEN 2A and Hirschsprung's disease. CONCLUSION: Detection of the mutated RET gene carriers may be used for genetic counseling of potential risk for Hirschsprung's disease as well as MEN 2A in the affected families.     

Phenotypic expression of a family with multiple endocrine neoplasia type 2A due to a RET mutation at codon 618

BACKGROUND: Multiple endocrine neoplasia type 2A (MEN2A) is caused by missense mutations in the RET proto-oncogene on chromosome 10. This paper reports the phenotypic expression of a family with MEN2A, in which serine substitutes for cysteine at codon 618 in exon 10 of the RET gene. It was first claimed that medullary thyroid cancer (MTC) with this rare mutation led to mild disease; this has recently been updated to intermediate-high risk, based on stratified genetic information. METHODS: The family was mapped over six generations. In 1971 family members were invited to join a screening programme. Genetic testing was started in 1994. RESULTS: Twenty-two individuals with MTC were identified, 16 by the screening programme. One screened patient had a phaeochromocytoma and four had hyperparathyroidism. At surgery for MTC 12 patients had local tumour metastases and two young patients also had liver metastases. No screened patient died from MTC during a mean observation time of 19 years. Six other family members were diagnosed with MTC by signs and symptoms, five of whom died from MTC. CONCLUSION: Because of the great interindividual differences in tumour aggressiveness within the family it is impossible to predict whether an individual gene carrier will have an aggressive MTC or not. This unpredictability is an additional argument, besides those obtained in stratified genetic studies, for operating on gene carriers at young age.     

家系多发性内分泌肿瘤诊治及RET原癌基因突变的研究

目的 探讨多发性内分泌肿瘤( MEN)的临床诊治特点及RET原癌基因检测的临床意义。 方法 家系中诊断MEN患者3例,男1例,50岁;女2例,38岁和33岁。2例行双侧肾上腺全切术：1例行保留双侧肾上腺的肾上腺嗜铬细胞瘤切除术。3例均行甲状腺全切+颈部淋巴结清扫术。家系中12名成员抽血,提取基因组DNA,对RET原癌基因第10、11外显子行PCR检测,对PCR产物进行基因测序。 结果 3例患者病理诊断为双肾上腺嗜铬细胞瘤+甲状腺髓样癌。38岁、33岁女患者及男患者术后分别随访5年、4年2个月、1年6个月,均无肿瘤复发或转移。3例均检测到RET原癌基因第11外显子TGC→CGC( Cys634 Arg)错义突变,使编码氨基酸由半胱氨酸变成精氨酸。家系其他成员中发现2名该突变基因携带者。 结论 对MEN高危家族的RET原癌基因检测筛选及早期手术干预是治愈MEN的关键。     

A case of multiple endocrine neoplasia type 2A (MEN2A) with a mutation in the RET gene]

A 44-year-old woman complained of headache and palpitation. Magnetic resonance imaging showed bilateral adrenal tumors 10 x 9 cm in size on the left side and 8 x 4 cm in size on the right side. CT scan revealed a 0.7 x 0.7 cm mass in the thyroid. Hormonal examinations showed high values of urinary cathecholamines and serum calcitonin. DNA sequence analysis of peripheral white blood cells revealed that codon 634 in exon 11 of the RET gene was mutated from TGC (Cys) to TAC (Tyr). From these findings, a diagnosis was made of MEN2A with bilateral adrenal pheochromocytomas and medullary thyroid carcinoma. Bilateral adrenalectomy and thyroidectomy were performed. The same mutation of the RET gene was detected in all her 3 children, in two of whom, early stage medullary thyroid carcinoma was detected and thyroidectomy was performed. DNA analysis of the RET gene was useful for the diagnosis of carriers of MEN2A and the early detection of medullary thyroid carcinoma.     

Gastrointestinal manifestations of multiple endocrine neoplasia type 2

OBJECTIVE: To determine the clinical features, natural history, and role of surgery for gastrointestinal manifestations of the multiple endocrine neoplasia type 2 (MEN 2) syndromes. SUMMARY BACKGROUND DATA: The MEN 2 syndromes are characterized by medullary thyroid carcinoma and other endocrinopathies. In addition, some patients with MEN 2A develop Hirschsprung's disease (HD), and all patients with MEN 2B have intestinal neuromas and megacolon that can cause significant gastrointestinal problems. METHODS: From 83 families with MEN 2A, eight patients with HD were identified (MEN 2A-HD). These and all patients with MEN 2B followed at the authors' institution (n = 53) were sent questionnaires to describe the onset and type of gastrointestinal symptoms and treatment they had before the diagnosis of MEN 2. Records of all patients responding were reviewed, including radiographic imaging, histology, surgical records, and genetic testing. RESULTS: Thirty-six of the 61 patients (59%) responded (MEN 2A = 8, MEN 2B = 28) to the questionnaires. All patients with MEN 2A-HD were operated on for HD 2 to 63 years before being diagnosed with MEN 2. All patients responding were underweight as infants and had symptoms of abdominal pain, distention, and constipation. Eighty-eight percent had hematochezia, 63% had emesis, and 33% had intermittent diarrhea before surgery. All patients with MEN 2A-HD had rectal biopsies with a diverting colostomy as the initial surgical procedure. This was followed by a colostomy takedown and pull-through procedure at a later interval. Ninety-three percent of patients with MEN 2B had gastrointestinal symptoms 1 to 24 years before the diagnosis of MEN 2. Symptoms included flatulence (86%), abdominal distention or being underweight as a child (64%), abdominal pain (54%), constipation or diarrhea (43%), difficulty swallowing (39%), and vomiting (14%). Seventy-one percent of patients with MEN-2B with gastrointestinal symptoms had radiographic imaging, 32% were admitted to the hospital, and 29% underwent surgery. CONCLUSIONS: Patients with MEN 2A-HD had a typical HD presentation and always required surgery. Patients with MEN 2B have significant gastrointestinal symptoms, but less than a third had surgical intervention. Understanding the clinical course and differences in these patients will improve clinical management.     

RET proto-oncogene testing in infants presenting with Hirschsprung disease identifies 2 new multiple endocrine neoplasia 2A kindreds

Background

Multiple endocrine neoplasia 2A (MEN 2A) is a genetic syndrome manifesting as medullary thyroid carcinoma (MTC), hyperparathyroidism, and pheochromocytoma. Multiple endocrine neoplasia 2A results from mutations in the RET proto-oncogene. Hirschsprung disease (HSCR) is a rare manifestation of MEN 2A and has been described in known MEN 2A families.

Methods

Here we describe 2 MEN 2A families that were only identified after the diagnosis of HSCR.

Results

Kindred 1: A boy presented in infancy with HSCR. Genetic screening revealed a C609Y mutation, which is consistent with MEN 2A. Evaluation of his sister, father, and grandmother revealed the same mutation. All 3 had thyroidectomies demonstrating C-cell hyperplasia. The grandmother had a microscopic focus of MTC.Kindred 2: An infant boy and his sister were diagnosed with HSCR as neonates. Genetic testing demonstrated a C620R gene mutation consistent with MEN 2A. Total thyroidectomies revealed metastatic MTC in the father and C-cell hyperplasia in both children.

Conclusions

Hirschsprung disease can be the initial presentation of MEN 2A. We strongly recommend that genetic screening be performed in patients presenting with HSCR, looking for the known RET mutations associated with MEN 2A. If a mutation consistent with MEN 2A is detected, genetic screening of all first-degree relatives in the kindred is recommended.     

Prophylactic thyroidectomy in pediatric carriers of multiple endocrine neoplasia type 2A or familial medullary thyroid carcinoma: mutation in C620 is associated with Hirschsprung's disease

Purpose

Prophylactic total thyroidectomy is now recommended after having confirmed RET mutations in children of parents with multiple endocrine neoplasia type 2 or familial medullary thyroid carcinoma. We reviewed our experience to determine the incidence of medullary thyroid carcinoma with respect to age at surgery, the location of the mutation, and its association with Hirschsprung's disease (HD).

Methods

A retrospective review from 1996 to 2005 revealed 20 children with genetic screening for multiple endocrine neoplasia type 2A or familial medullary thyroid carcinoma who underwent a prophylactic total thyroidectomy with parathyroid gland preservation.

Results

The median age of the 20 patients (9 boys and 11 girls) included in this study was 8.2 years (range, 3.7-16.9 years) at the time of their surgery. Final pathology revealed normal thyroid tissue (n = 3; median age, 5.9 years), C-cell hyperplasia (n = 13; median age, 10 years), or medullary thyroid carcinoma (n = 4; median age, 8 years). Four children, all with mutations in C620, had a previous diagnosis of HD. At a median follow-up of 3.7 years (range, 1 month to 8.4 years), all patients were well and cancer free.

Conclusions

There is no correlation between histologic findings and median age at surgery. Hirschsprung's disease was found in 50% of the patients with the RET mutation in C620. In children of C620 parents, symptoms of HD should be actively sought, and if such are found, rectal biopsies should be performed even if mutation results are not yet available. Based on the age of the earliest cancer and the safety of total thyroidectomy, children should promptly undergo surgery after genetic screening and before their fifth year of life.     

2型多发内分泌腺瘤病的诊断及外科治疗

目的探讨2型多发内分泌腺瘤病的临床特点、治疗方法及疗效。方法回顾分析我院1980～2002年诊治的8例2型多发内分泌腺瘤病患者的临床特点、诊断及治疗方法与疗效。结果7例有阵发性高血压,5例最高血压超过200mmHg(1mmHg=0．133kPa),3例查体发现肿瘤。经B超、CT及24h尿儿茶酚胺检查确定诊断,2A型6例,2B型2例;表现为甲状腺髓样癌合并嗜铬细胞瘤伴或不伴甲状旁腺腺瘤或增生(6例),1例伴多发黏膜神经瘤,1例为嗜铬细胞瘤伴有马凡综合征;双侧肾上腺肿瘤7例;分期行肾上腺与甲状腺、甲状旁腺结节切除或次全切除术。术后平均随访9年,效果良好。结论2型多发内分泌腺瘤病的诊断主要依赖相应的内分泌检查及B超和CT检查,手术是主要的治疗手段,当嗜铬细胞瘤与其他肿瘤同时存在时,宜首先切除嗜铬细胞瘤。     

Multiple endocrine neoplasia type II B with symptoms suggesting Hirschsprung's disease: a case report

A 3-year-old child was referred with a tentative diagnosis of Hirschsprung's disease because of life-long constipation and "megacolon" demonstrated radiographically. Our rectal biopsy revealed hyperganglionosis suggestive of multiple endocrine neoplasia (MEN) type II B. This, in addition to an elevated serum calcitonin level, prompted surgical removal of her thyroid, which appeared grossly normal but on sectioning, contained a medullary carcinoma in each lobe. She remains disease-free 5 years later. Gastrointestinal symptoms are a significant component of the MEN type II B syndrome, and often antedate the full phenotypic expression of the syndrome and the development of potentially lethal endocrine neoplasms. On the basis of this experience, it is recommended that MEN II B be included in the differential diagnosis of chronic constipation.     

The natural history of multiple endocrine neoplasia type 2A—A clinical analysis

The records of 18 patients with multiple endocrine neoplasia (MEN) type 2A in a family consisting of 87 members in 5 generations, were reviewed with respect to age at onset and length of survival in a study of the natural history of this syndrome. Of these 18 patients, 8 were alive following surgical treatment, while 10 had died without treatment. The clinical onset of medullary thyroid carcinoma was noticed as a nodule in the neck at between 17 and 34 years of age (mean 24 years); the onset of pheochromocytoma was characterized by palpitation, hypertensive attacks or recurrent headache at between 17 and 42 years of age (mean 27 years); and death occurred in 10 patients at between 23 and 67 years of age (mean 40.6 years). This information on the age at onset of individual clinical manifestations, and on the length of survival of gene carriers, may be useful for clinicians who are asked to assess the risk of the development of this syndrome in a genetically predisposed asymptomatic individual, because screening tests are often refused by members of Japanese families with MEN type 2A.     

Laparoscopic resection of periadrenal paraganglioma in a patient with multiple endocrine neoplasia type 2A

We report here a case of recurrent pheochromocytoma successfully managed by laparoscopic surgery in a patient with multiple endocrine neoplasia type 2A. A 25-year-old man presented with the contralateral adrenal mass after earlier right adrenalectomy. For the preoperative diagnosis of left adrenal pheochromocytoma, adrenal sparing surgery was considered. From the intraoperative laparoscopic view, we found that the tumor originated in periadrenal sympathetic ganglia, and laparoscopic excision of paraganglioma was successfully performed that preserved the integrity of normal adrenal gland. Extra-adrenal pheochromocytoma is rather rare in MEN 2A and it is important to identify precise intraoperative localization of pheochromocytoma with laparoscopic surgery.     

The natural history of multiple endocrine neoplasia type 2A--a clinical analysis

The records of 18 patients with multiple endocrine neoplasia (MEN) type 2A in a family consisting of 87 members in 5 generations, were reviewed with respect to age at onset and length of survival in a study of the natural history of this syndrome. Of these 18 patients, 8 were alive following surgical treatment, while 10 had died without treatment. The clinical onset of medullary thyroid carcinoma was noticed as a nodule in the neck at between 17 and 34 years of age (mean 24 years); the onset of pheochromocytoma was characterized by palpitation, hypertensive attacks or recurrent headache at between 17 and 42 years of age (mean 27 years); and death occurred in 10 patients at between 23 and 67 years of age (mean 40.6 years). This information on the age at onset of individual clinical manifestations, and on the length of survival of gene carriers, may be useful for clinicians who are asked to assess the risk of the development of this syndrome in a genetically predisposed asymptomatic individual, because screening tests are often refused by members of Japanese families with MEN type 2A.     

Evaluation of a family at risk for the multiple endocrine neoplasia type 2A (MEN 2A) syndrome.

A multidisciplinary group was formed to advise on strategy and to co-ordinate the management of a family at risk for the multiple endocrine neoplasia type 2A (MEN 2A) syndrome. A proposed strategy is outlined in which DNA analysis and provocative calcitonin testing is central.     

Subtotal adrenalectomy for phaeochromocytoma in multiple endocrine neoplasia type 2A.

OBJECTIVE: To describe our surgical technique for, and results of, subtotal adrenalectomy for phaeochromocytoma in multiple endocrine neoplasia (MEN) type 2. DESIGN: Retrospective study. SETTING: Teaching hospital, The Netherlands. SUBJECTS: 6 patients (four women and 2 men, mean age 35 years, range 31-46) with MEN type 2 who presented between 1993 and 1996. INTERVENTIONS: Cortical sparing adrenalectomy (n =4) together with contralateral total adrenalectomy in bilateral disease (n = 2). MAIN OUTCOME MEASURES: Morbidity, mortality, adrenal function postoperatively, and recurrence. RESULTS: Cortical sparing adrenalectomy leaving adequate adrenal reserve was possible in all cases. There was no operative morbidity or mortality. Mean follow-up was 40 months (range 1347). One patient developed a recurrent phaeochromocytoma 24 months after subtotal adrenalectomy. CONCLUSIONS: Subtotal adrenalectomy with preservation of adequate adrenal cortical reserve was feasible in all cases. Long term follow-up is necessary to establish its definitive place in the treatment of familial phaeochromocytoma.     

多发性内分泌肿瘤2型的诊断和外科处理

目的 探讨多发性内分泌肿瘤2型（multiple endocrine neoplasia,MEN2）的诊断和外科处理方法.方法 回顾性研究1997年6月至2006年6月我院诊断和治疗的MEN2患者28例的临床资料.结果 MEN2a型25例,其中23例分属7个家系,均有RET基因11外显子634编码子突变;MEN2b型3例,无家族史,为RET基因16外显子918编码子突变.MEN2a型中22例有甲状腺肿物伴降钙素升高,其中17例经病理证实为甲状腺髓样癌;12例合并嗜铬细胞瘤,其中5例为多发性,2例恶性;5例合并甲状旁腺功能亢进症,3例无临床症状及生化改变.3例MEN2b型均为甲状腺髓样癌合并黏膜神经瘤病和马凡样体形,其中1例伴双侧肾上腺嗜铬细胞瘤.MEN2a型中12例接受双侧甲状腺全切除＋双侧颈淋巴清扫,5例行甲状腺肿物切除;甲状旁腺病变在甲状腺手术时一并处理;9例接受11次肾上腺肿瘤摘除术,3例为双侧肾上腺手术.3例MEN2b型均行双侧甲状腺全切除＋双侧颈淋巴清扫.结论 MEN2型以甲状腺髓样癌为主要病变,基因筛查可帮助早期诊断.根治性甲状腺切除能预防和治疗甲状腺髓样癌.     

Long-term follow-up of a large North American kindred with multiple endocrine neoplasia type 2A.

BACKGROUND. Sixty-one patients with multiple endocrine neoplasia (MEN) type 2A (27 men; 34 women; mean age, 39 years) from a single kindred (76 affected, 49 at risk) were followed 1 month to 33 years (median, 14 years) after diagnosis for disease expression. METHODS. Peripheral basal and pentagastrin-stimulated calcitonin, parathyroid hormone, and calcium levels were measured in 60 patients, 58 of whom had undergone previous thyroidectomy; the calcitonin concentration in four patients was concomitantly determined in the hepatic and internal jugular veins. Biochemical or radiographic screening for pheochromocytoma was performed in 58 patients. RESULTS. Recurrence of medullary thyroid carcinoma (MTC) developed in nineteen (33%) of 58 patients after they underwent thyroidectomies. In 14 of 19 patients regional metastases were inapparent at initial operation, and lymphadenectomy was not undertaken. Three patients underwent neck reexploration with removal of micrometastases after selective venous studies were performed. One patient, 33 years of age, died of MTC, and two patients who refused thyroidectomy are alive at 76 and 83 years of age. Fifteen patients are alive with disease 8 to 33 years after they underwent thyroidectomies. All patients identified by prospective screening remain pentagastrin negative. Pheochromocytoma developed in six patients (10%), and four patients have Hirschsprung's disease. Hyperparathyroidism was present in seven patients and did not occur in those with minimal MTC. CONCLUSIONS. These observations suggest that (1) the course of MTC in MEN 2A is highly variable, (2) early treatment of C-cell disease can be curative, (3) routine lymphadenectomy for occult micrometastases may be necessary for cure of MTC, and (4) the hyperparathyroidism of MEN 2A may not be a primary genetic event.