Clinical investigation and ret proto / 西安交通大学学报(医学版)

【Objective】 To investigate the clinical features and gene analysis of one pedigree with multiple endocrine neoplasia type 2A （MEN2A） so as to clarify the diagnosis and classification of the disease， guide treatment and prevention， and improve prognosis. 【Methods】 The clinical data of a 36-member MEN2A family， including 6 probands， with medullary thyroid carcinoma， were investigated， and the peripheral blood genomic DNA of 28 family members （blood sample of one proband was not collected） was extracted. PCR amplification was performed on exons 8， 10， 11， 13， 14， 15 and 16 of the RET gene， and the products were directly sequenced. 【Results】 Review of the medical history showed that two probands with medullary thyroid carcinoma were accompanied with hyperparathyroidism， and one family member had pheochromocytoma. The RET gene mutation test confirmed that 13 family members， consisting of 5 probands and 8 family members， had the RET proto-oncogene exon 10 missense mutation. The heterozygous missense had mutation c.1852T>A， leading to the conversion of cysteine （TGC） at position 618 to serine （AGC） （Cys618Ser）. All subjects carrying RET gene Cys618Ser mutation had abnormal thyroid ultrasound change， accompanied with elevated calcitonin levels. Subjects carrying wild type of RET gene had normal calcitonin levels. The family was finally diagnosed with MEN2A by RET gene detection. 【Conclusion】 RET gene detection plays key role in the diagnosis and treatment of patients with MEN2A family and has guiding value in the follow-up and prognosis of asymptomatic carriers. There is a positive correlation between calcitonin level and the RET protooncogene mutation Cys618Ser. Patients suspected of MEN2A should be screened in time.

Diagnóstico, tratamento e seguimento do carcinoma medular de tireoide: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia / Diagnosis, treatment, and follow-up of medullary thyroid carcinoma: recommendations by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism

Introdução O carcinoma medular de tireoide (CMT) origina-se das células parafoliculares da tireoide e corresponde a 3-4% das neoplasias malignas da glândula. Aproximadamente 25% dos casos de CMT são hereditários e decorrentes de mutações ativadoras no proto-oncogene RET (REarranged during Transfection). O CMT é uma neoplasia de curso indolente, com taxas de sobrevida dependentes do estádio tumoral ao diagnóstico. Este artigo descreve diretrizes baseadas em evidências clínicas para o diagnóstico, tratamento e seguimento do CMT. Objetivo O presente consenso, elaborado por especialistas brasileiros e patrocinado pelo Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia, visa abordar o diagnóstico, tratamento e seguimento dos pacientes com CMT, de acordo com as evidências mais recentes da literatura. Materiais e métodos: Após estruturação das questões clínicas, foi realizada busca das evidências disponíveis na literatura, inicialmente na base de dados do MedLine-PubMed e posteriormente nas bases Embase e SciELO – Lilacs. A força das evidências, avaliada pelo sistema de classificação de Oxford, foi estabelecida a partir do desenho de estudo utilizado, considerando-se a melhor evidência disponível para cada questão. Resultados Foram definidas 11 questões sobre o diagnóstico, 8 sobre o tratamento cirúrgico e 13 questões abordando o seguimento do CMT, totalizando 32 recomendações. Como um todo, o artigo aborda o diagnóstico clínico e molecular, o tratamento cirúrgico inicial, o manejo pós-operatório e as opções terapêuticas para a doença metastática. Conclusões O diagnóstico de CMT deve ser suspeitado na presença de nódulo tireoidiano e história ...

Introduction Medullary thyroid carcinoma (MTC) originates in the thyroid parafollicular cells and represents 3-4% of the malignant neoplasms that affect this gland. Approximately 25% of these cases are hereditary due to activating mutations in the REarranged during Transfection (RET) proto-oncogene. The course of MTC is indolent, and survival rates depend on the tumor stage at diagnosis. The present article describes clinical evidence-based guidelines for the diagnosis, treatment, and follow-up of MTC. Objective The aim of the consensus described herein, which was elaborated by Brazilian experts and sponsored by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism, was to discuss the diagnosis, treatment, and follow-up of individuals with MTC in accordance with the latest evidence reported in the literature. Materials and methods: After clinical questions were elaborated, the available literature was initially surveyed for evidence in the MedLine-PubMed database, followed by the Embase and Scientific Electronic Library Online/Latin American and Caribbean Health Science Literature (SciELO/Lilacs) databases. The strength of evidence was assessed according to the Oxford classification of evidence levels, which is based on study design, and the best evidence available for each question was selected. Results Eleven questions corresponded to MTC diagnosis, 8 corresponded to its surgical treatment, and 13 corresponded to follow-up, for a total of 32 recommendations. The present article discusses the clinical and molecular diagnosis, initial surgical treatment, and postoperative management of MTC, as well as the therapeutic options for metastatic disease. Conclusions 7 .

Carcinoma medular de tiroides: estudio multicéntrico. Presentación y evolución en 219 pacientes / Medullary Thyroid Carcinoma: Clinical Presentation and Outcome in 219 Patients

Ante la baja frecuencia del carcinoma medular de tiroides (CMT), en el Departamento de Tiroides de SAEM nos propusimos realizar un estudio de cohorte, observacional, retrospectivo y multicéntrico. Se incluyeron 219 pacientes con diagnóstico histológico de CMT. El 65 % fueron mujeres, la edad promedio fue de 39 ± 20 años (1 a 84 años); 44-% de los casos fueron familiares. Las formas de presentación más frecuentes fueron nódulo tiroideo (58 %) y pesquisa genética por antecedente familiar (22 %). Si bien la citología tiroidea fue diagnóstica de CMT en el 39 % de los casos, fue determinante de indicación quirúrgica en el 79 %. En el 47 % de los pacientes el diagnóstico de CMT se obtuvo previamente al tratamiento quirúrgico inicial por punción aspiración con aguja fina (PAAF), estudio genético o nivel de calcitonina (CT)). El 65 % se presentó en estadios avanzados (TNM III y IV). El estudio del protoncogen RET se realizó en 162 pacientes (74 %). En el 49 % se observó mutación siendo la más frecuente (76 %) en el codón 634. La forma hereditaria más frecuentemente observada fue el síndrome de neoplasia endocrina múltiple (NEM) 2A (57 % de los casos familiares), seguida por carcinoma medular familiar (25 %) y NEM 2B (13 %). Los casos familiares tuvieron menor edad al diagnóstico y mayor frecuencia de diagnóstico prequirúrgico. Los casos índice tuvieron mayor edad al momento del diagnóstico, mayores niveles de antígeno carcinoembrionario (CEA) y CT prequirúrgicos, mayor proporción de estadios III y IV y mayor porcentaje de evidencia de enfermedad al momento de la última consulta que aquellos detectados por pesquisa. En 143 pacientes (65 %) se obtuvieron registros completos de seguimiento en los que se analizaron los factores relacionados con la evolución. La mediana de seguimiento fue de 44 meses: fallecieron 21 pacientes (14,6 %) y 122 (86 %) viven; 76 de estos (54 %) se encuentran libres de enfermedad. El grupo con evidencia de enfermedad se presentó en estadios más avanzados. Resultaron factores de mayor riesgo para evidencia de enfermedad: sexo masculino, CMT esporádico, niveles elevados de CT prequirúrgicos, estadio IV y presencia de metástasis. Los niveles de CT posquirúrgicos fueron menores en aquellos pacientes que en la evolución final no presentaron evidencia de enfermedad. El principal factor pronóstico de la evolución de los pacientes con CMT fue el estadio de presentación, determinando la importancia del diagnóstico precoz con el fin de poder implementar un tratamiento quirúrgico curativo en estadios menos avanzados.

Due to the low frequency of medullary thyroid cancer (MTC), an observational, cohort, retrospective multicenter study was conducted at the Thyroid Department of the Endocrine and Metabolism Argentine Society (SAEM). We included 219 patients with histologically proven MTC, with a mean age of 39 ± 20 yr (range 1-84 years). Sixty five percent were women and 44% were familial cases. The most common presentations were thyroid nodule (58 %) and genetic screening due to family history (22 %). In 39 % of patients, diagnosis of MTC was made by fine needle aspiration, but cytology led to surgery in 79 %. In 47 % of patients, MTC was diagnosed by cytology, calcitonin (CT) levels or genetic studies prior to initial surgery. Sixty five percent of patients had advanced stages of the disease (TNM III or IV) at diagnosis. Proto-oncogene RET was studied in 162 patients (74 %). In 49% a mutation was reported, most frequently in codon 634 (76 %). Regarding hereditary forms of MTC, MEN 2A was the most frequent (57%), followed by familial MTC in 25 % and MEN 2B in 13 % of cases. Familial cases were younger subjects and had more frequently a pre-surgery diagnosis. Index cases were older, with higher CEA and CT levels, presented in more advanced stages and had more frequently evidence of disease at final assessment than patients who were diagnosed by genetic screening. Follow-up records of 143 patients were analyzed (65%); median time was 44 months; 21 patients died (14.6 %) and 122 survived (86 %), 76 showed no evidence of disease (NED) (54 %). High risk factors for evidence of disease at the final evaluation were: male gender, sporadic MTC, higher CT pre-surgery levels, stage IV and metastasis. Post surgery CT levels were lower in patients with NED. Stage at initial diagnosis was the main prognostic factor in patients with MTC, determining the importance of early detection for performing curative surgery in less advanced stages.

Genetic analysis of a Chinese Han family with multiple endocrine neoplasia type 2A.

Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant disorder that can be distinguished as three different syndromes: multiple endocrine neoplasia type 2A (MEN2A), MEN2B and familial medullary thyroid carcinoma (FMTC). This disorder is usually caused by the mutations of the rearranged during transfection protooncogene gene (RET) or the neurotrophic tyrosine kinase receptor type 1 gene (NTRK1). To investigate the genetic cause in a Chinese Han family with MEN2A and the genotype-phenotype correlations, nine members belonging to 3 generations of MEN2A family with 5 affected subjects underwent genetic analysis. Standard GTG-banded karyotype analysis and sequencing of the RET and NTRK1 genes were performed to identify the genetic cause of this family. A heterozygous mutation p.Cys634Arg in the RET gene was identified in 5 patients with MEN2A and one asymptomatic family member. The phenotype of patients was that of classic MEN2A, characterized by medullary thyroid carcinoma and phaeochromocytoma. The clinical features of all cases with RET mutations varied greatly, including onset age of clinical manifestations, severity and comorbidities. Thus, this study not only identified the hereditary nature of the MEN2A in the cases, but also discovered a family member harboring the same p.Cys634Arg mutation, who was unaware of his condition. These finding may provide new insights into the cause and diagnosis of MEN2A and have implications for genetic counseling.

RET codon 609 mutations: a contribution for better clinical managing

Medullary thyroid carcinoma currently accounts for 5-8% of all thyroid cancers. The clinical course of this disease varies from extremely indolent tumors that can go unchanged for years to an extremely aggressive variant that is associated with a high mortality rate. As many as 75% of all medullary thyroid carcinomas are sporadic, with an average age at presentation reported as 60 years, and the remaining 25% are hereditary with an earlier age of presentation, ranging from 20 to 40 years. Germline RET proto-oncogene mutations are the genetic causes of multiple endocrine neoplasia type 2 and a strong genotype-phenotype correlation exists, particularly between a specific RET codon mutation and the (a) age-related onset and (b) thyroid tumor progression, from C-cell hyperplasia to medullary thyroid carcinoma and, ultimately, to nodal metastases. RET mutations predispose an individual to the development of medullary thyroid carcinomas and can also influence the individual response to RET protein receptor-targeted therapies. RET codon 609point mutations are rare genetic events belonging to the intermediate risk category for the onset of medullary thyroid carcinoma. A large genealogy resulting in a less aggressive form of medullary thyroid carcinoma is associated with the high penetrance of pheochromocytoma and has been reported in the literature. In this short review article, we comment on our previous report of a large multiple endocrine neoplasia type 2A kindred with the same Cys609Ser germline RET mutation in which, conversely, the syndrome was characterized by a slightly aggressive, highly penetrant form of medullary thyroid carcinoma that was associated with low penetrance of pheochromocytoma and primary hyperparathyroidism.

Retroperitoneoscopic adrenalectomy in pheochromocytoma

Since the first laparoscopic adrenalectomy, the technique has evolved and it has become the standard of care for many adrenal diseases, including pheochromocytoma. Two laparoscopic accesses to the adrenal have been developed: transperitoneal and retroperitoneal. Retroperitoneoscopic adrenalectomy may be recommended for the treatment of pheochromocytoma with the same peri-operative outcomes of the transperitoneal approach because it allows direct access to the adrenal glands without increasing the operative risks. Although technically more demanding than the transperitoneal approach, retroperitoneoscopy can shorten the mean operative time, which is critical for cases with pheochromocytoma where minimizing the potential for intra-operative hemodynamic changes is essential. Blood loss and the convalescence time can be also shortened by this approach. There is no absolute indication for either the transperitoneal or retroperitoneal approach; however, the latter procedure may be the best option for patients who have undergone previous abdominal surgery and obese patients. Also, retroperitoneoscopic adrenalectomy is a good alternative for treating cases with inherited pheochromocytomas, such as multiple endocrine neoplasia type 2A, in which the pheochromocytoma is highly prevalent and frequently occurs bilaterally.

RET gene mutations and polymorphisms in medullary thyroid carcinomas in Indian patients.

Germline mutations of RET gene are pathognomonic of multiple endocrine neoplasia (MEN; MEN 2A/MEN 2B) and familial medullary thyroid carcinoma (FMTC), constituting 25% of medullary thyroid carcinomas (MTCs). We investigated RET gene mutations and polymorphisms at exons 10, 11, 13, 14, 15 and 16 in 140 samples, comprising 51 clinically diagnosed MTC patients, 39 family members of patients and 50 normal individuals. The method of choice was PCR and direct nucleotide sequencing of the PCR products. RET gene mutations were detected in 15 (29.4%) patients, with MEN 2A/FMTC in 13 patients and MEN 2B in 2 patients. Further, 39 family members of seven index cases were analysed, wherein four of the seven index cases showed identical mutations, in 13 of 25 family members. We also examined single nucleotide polymorphisms (SNPs) in RET gene exons in 101 unrelated samples. Significant differences in the allelic frequencies of SNPs at codons 691, 769, 836 and 904 between patient and control groups were not observed. However, SNP frequencies were significantly different in the Indian group as compared with other European groups. We identified two novel, rare and unique SNPs separately in single patients. Our study demonstrated presence of MEN 2A/MEN 2B/FMTC-associated mutations in accordance with the reported literature. Thus, RET gene mutations in exons 10, 11, 13, 14, 15 and 16 constitute a rapid test to confirm diagnosis and assess risk of the disease in familial MEN 2A/MEN 2B/FMTC.

Unpredicted tachycardia and hypotension in a patient with medullary thyroid cancer and undiagnosed pheochromocytoma: A case report / 대한마취과학회지

A 35 year old woman with hypercalcitoninemia was scheduled for an operation to treat her medullary thyroid cancer (MTC). TIVA with propofol and remifentanil was planned, and about 3 minutes after the infusion of anesthetics, her heart rate was suddenly elevated to 180/min and the systolic blood pressure was lowered to nearly 50 mmHg. The blood pressure returned to normal after the injection of phenylephrine 100 microgram and a rapid infusion of 700 ml crystalloid solution. After the operation, bilateral pheochromocytoma and a RET proto-oncogene mutation related with multiple endocrine neoplasia 2A (MEN-2A) were found. Patients with MTC can present with peripheral vasodilation and relative hypovolemia that are related with hypercalcitoninemia. Patients with MEN-2A can be anesthetized for a MTC operation without the appropriate preparation for their pheochromocytoma. Therefore, we suggest that patients with MTC and hypercalcitoninemia should be cautiously anesthetized with TIVA. They also should be screened for pheochromocytoma and the RET proto-oncogene mutation to prevent deleterious hemodynamic events during anesthesia.

Importância da identificação das mutações do protooncogene RET e sua atuação no desenvolvimento dos diversos fenótipos das neoplasias endócrinas múltiplas tipo 2 / Importance of RET proto-oncogene mutations identification and its performance in thedevelopment of the multiples endocrines neoplasias type 2 several phenotypes

A hereditariedade autossômica dominante da neoplasia endócrina múltipla tipo 2 (NEM 2) relaciona-se à ativação do proto-oncogene RET, através de mutações missense. As mutações do RET são encontradas em 95% dos casos índices de NEM 2 e apresentam relação direta entre sua localização codon específica e os diversos fenótipos desenvolvidos, dentre eles, carcinoma medular datireóide, feocromocitoma e/ou hiperparatireoidismo. Baseando-se em análises bioquímicas e genéticas, é possível efetuar um diagnósticoprematuro, viabilizando a intervenção cirúrgica em tempo hábil. A periodicidade da monitorização bioquímica é ditada pelo fenótipopresente, pelas manifestações clínicas familiares e pelo genótipo RET. A recomendação da análise genética deve ser feita a todos indivíduos afetados e também a seus ascendentes e descendentes diretos, caso alguma mutação esteja presente; permitindo identificar os portadores de mutações RET, previamente ao início da sintomatologia. Neste trabalho, serão discutidos os aspectos molecularesdos diversos fenótipos da NEM 2, bem como a importância da identificação genotípica do proto-oncogene RET e sua interação com os testes bioquímicos visando o diagnóstico precoce, prevenção, monitorização, screening familiar e, portanto, maior sobrevidado paciente.

The dominant autossomic hereditarity of the multiple endocrine neoplasia type 2 (MEN 2) is related to RET proto-oncogene activation, through mutations missense. RET mutations are found in 95% of MEN 2 index cases and present direct relation between its specific localization codon and the diverse developed phenotypes, among them, medullary thyroid carcinoma, pheochromocytoma and/or hyperparathyroidism. Being based on biochemists and genetics analyses, it is possible to perform a premature diagnosis, making possible a surgical intervention in the right time. The biochemist monitoring regularity is determined by present phenotype, the familiar clinical manifestations and RET genotype. The recommendation of the genetic analysis must be made to all affected individuals and also their ascendants and descendants, in case some mutation is present, allowing to identify the RET mutations carriers previously to the beginning of the symptomatology. In this work, the molecular aspects of MEN 2 diverse phenotypes will be discussed, as well as the importance of the RET proto-oncogene genotypic identification and its interaction with the biochemists tests aiming the precocious diagnosis, prevention, monitoring, familiar screening e, therefore, the patient’s longer survival.

Analysis of RET Gene Point Mutation in a Family with Multiple Endocrine Neoplasia Type 2A / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Multiple Endocrine Neoplasia type 2A (MEN 2A) is a syndrome that encompasses medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. Since MEN 2A is inherited as autosomal dominant, early detection and treatment is crucial. A genetic analysis of RET proto-oncogene of the family members of an index patient diagnosed as MEN 2A is reported. SUBJECTS AND METHOD: A patient diagnosed as MEN 2A and his 13 family members across two generations were studied. Initially, DNA was extracted from the peripheral blood leukocyte of family members and PCR amplification of exons 10, 11, 13, 14, 15, and 16 was performed, followed by investigation of point mutation on the RET proto-oncogene using a DNA sequence analyzer. Cervical ultrasonography was carried out in the 3 nephews who were revealed to have RET proto-oncogene point mutation. RESULTS: Point mutations of TGC (cys) to TGG (Trp) at codon 634 of exon 11 at RET proto-oncogene was detected by using automatic DNA sequence analyzing method in the index patient. The same point mutation was identified in 7 of the 13 family members. Cervical ultrasonography revealed bilateral thyroid nodules in all 3 nephews who had point mutations of RET proto-oncogene. CONCLUSION: With the genetic analysis of RET proto-oncogene, limitations of the conventional calcitonin stimulation test may be overcome, and a more complete approach can be achieved through early diagnosis by carrying out this screening test for point mutations in family members of the patient with MEN 2A.

A Case of Parathyroid Carcinoma Invading Thyroid Gland as Solitary Nodular Form / 대한내분비학회지

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism and commonly metastasize to lymph node, lung, liver, and bone. In Korea, there has been no report of distant metastasis in parathyroid carcinoma except for one case of pulmonary metastasis. A 58-year-old man presenting with weakness, nausea, and a palpable thyroid nodule visited our hospital. Elevated serum calcium and parathyroid hormone (PTH) concentration allowed the diagnosis of hyperparathyroidism. Two discrete masses were identified by neck ultrasound scan, computed tomography (CI') and Tc-Sestamibi scan in the left lobe of thyroid gland and ipsilateral parathyroid gland. So multiple endocrine neoplasia (MEN) type 2A" was suspected initially, but postoperative histological diagnosis was left parathyroid carcinoma with solitary nodular lesion invading left thyroid gland. He was successfully treated with left parathyroidectomy and left thyroid lobectomy.

Cermline Mutation of RET Gene in A Multiple Endocrine Neoplasia Type 2A ( MEN2A ) Family / 대한암학회지

PURPOSE: Multiple Endocrine Neoplasia Type 2A (MEN 2A) is an autosomal dominant disease characterized by development of the medullary thyroid cancer, adrenal pheochromocytoma and parathyroid hyperplasia. Gennline mutations of RET gene, which cause a susceptibility to MEN 2A syndrome, have been reported in MEN 2A families. The identification of germline mutation in family members with hereditary tumor syndrome makes the presymptomatic diagnosis possible. However, there are only a few reports on the germline mutation of RET gene in Korean patients with MEN 2A. This study was performed to investigate the germline mutation of RET gene in a Korean MEN 2A family. MATERIALS AND METHODS: Blood samples were taken from family members of a MEN 2A family. Mutational status was investigated using single strand conformation polymorphism (SSCP) method, and following direct sequencing. Basal level of calcitonin was measured, and calcium provocation test was done when the result of basal level of calcitonin was equivocal. RESULTS: A missense type germline mutation of RET gene was identified at codon 634 (TGC->TGG) in eight patients from the family. All patients with the germline mutation of RET gene showed elevation of calcitonin level either in basal test or in calcitonin provocation test. CONCLUSION: We identified a germline mutation of RET gene in a family with MEN 2A, and it would make the accurate presymptomatic diagnosis possible.