Thyrotropin-secreting adenoma in multiple endocrine neoplasia type 1: one case report and literature review / 中华内分泌代谢杂志

Objective@#To improve the understanding of thyrotropin-secreting adenoma in multiple endocrine neoplasia type 1(MEN1) through analyzing the clinical diagnosis and treatment process, as well as outcomes in one case of this disorder.@*Methods@#The clinical manifestations, biochemical and hormone levels, imaging presentations, medical and surgical treatments, and post-operational pathologic findings in the process of diagnosis and treatment of a patient with thyrotropin-secreting adenoma in MEN1 were analyzed. The next generation sequencing followed by Sanger method was used for analyzing MEN1 and related genes. The results were evaluated with online PolyPhen2 and PROVEAN for variation hazard.@*Results@#One 19-year old male patient was diagnosed with hyperthyroidism due to thyrotoxicosis and high level of thyroid hormones(THs) with measurable TSH(2.78 mIU/L) and negative thyrotropin receptor antibody(TRAb). Meanwhile, primary hyperparathyroidism was suggested by hypercalcemia, hypophosphatemia, and elevated intact parathyroid hormone(PTH) level, all the parameters were returned to normal after surgical resection of the mass which was below the left thyroid lobe indicated by ultrasound and 99mTc scan. Thyrotoxicosis remained in spite of one year treatment with antithyroid drug, thyrotropinoma was then suspected, and subsequent MRI scan found a macroadenoma at right pituitary. TSH and THs returned to normal 1 month after transsphenoidal removal of the adenoma. As expected, immunohistochemical staining revealed TSH positive. In addition, a pancreatic mass was found by both CT and MRI scan, which was considered as a silent neuroendocrine tumor. Gene analysis revealed a missense mutation of MEN1 as c. 415C>T and p. His139Tyr(H139Y), which was predicted highly hazard. Only five cases of thyrotropinoma in MEN1 were previously reported.@*Conclusion@#Thyrotropinoma should be cautiously identified from hyperthyroidism to avoid misdiagnosis and mistreatment, and it should keep in mind that thyrotropinoma may be associated with MEN1 though it would be very rare.

A pedigree of multiple endocrine neoplasia type 1 with the proband initially presenting adrenal cortical carcinoma / 中华内分泌代谢杂志

[Summary]_ This is a pedigree of multiple endocrine neoplasia type 1(MEN1). The proband pursuit medical assistance because of hypertension and weakness. Adrenal cortical carcinoma with possible Cushing's syndrome was diagnosed after a series of tests. During this process, the proband was found to have hypercalcemia, and he was diagnosed as primary hyperparathyroidism. Adrenal carcinoma plus primary hyperparathyroidism suggested MEN1, which was confirmed by MEN1 gene 400_401insC mutation. Pedigree investigation found six additional patients, including one with high parathyroid hormone level and two without clinical evidence of any MEN1 diseases. The proband died of metastatic malignancy 7 months after diagnosis while the other 3 patients with clinically confirmed MEN1 tumor responded well to surgery, including one with adrenal cortical carcinoma.

Genetic Analysis of Multiple Endocrine Neoplasia Type 1 (MEN1) Leads to Misdiagnosis of an Extremely Rare Presentation of Intrasellar Cavernous Hemangioma as MEN1

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN1) is a rare inherited disorder characterized by the simultaneous occurrence of endocrine tumors in target tissues (mainly the pituitary, endocrine pancreas, and parathyroid glands). MEN1 is caused by mutations in the MEN1 gene, which functions as a tumor suppressor and consists of one untranslated exon and nine exons encoding the menin protein. This condition is usually suspected when we encounter patients diagnosed with tumors in multiple endocrine organs, as mentioned above. METHODS: A 65-year-old woman who underwent surgery for a pancreatic tumor (serous cystadenoma) 5 years previously was referred to our hospital due to neurologic symptoms of diplopia and left ptosis. Brain magnetic resonance imaging revealed a 3.4-cm lesion originating from the cavernous sinus wall and extending into the sellar region. It was thought to be a nonfunctioning tumor from the results of the combined pituitary function test. Incidentally, we found that she also had a pancreatic tumor, indicating the necessity of genetic analysis for MEN1. RESULTS: Genomic analysis using peripheral leukocytes revealed a heterozygous c.1621G>A mutation in the MEN1 gene that was previously reported to be either a pathogenic mutation or a simple polymorphism. We pursued a stereotactic approach to the pituitary lesion, and microscopic findings of the tumor revealed it to be an intrasellar cavernous hemangioma, a rare finding in the sellar region and even rarer in relation to oculomotor palsy. The patient recovered well from surgery, but refused further evaluation for the pancreatic lesion. CONCLUSION: There is great emphasis placed on genetic testing in the diagnosis of MEN1, but herein we report a case where it did not assist in diagnosis, hence, further discussion on the role of genetic testing in this disease is needed. Also, in cases of pituitary tumor with cranial nerve palsy, despite its low prevalence, intrasellar cavernous hemangioma could be suspected.

Mutation analysis in two Chinese families with multiple endocrine neoplasia type 1 / Análise de mutações em duas famílias chinesas com neoplasia endócrina múltipla tipo 1

OBJECTIVE: This study aimed at identifing mutations in two Chinese genealogies with MEN1. SUBJECTS AND METHODS: Three members of two Chinese families with MEN1 were enrolled in this study, and all of the coding regions and adjacent sequences of the MEN1 gene were amplified and sequenced. RESULTS: A recurrent mutation of heterozygous change T>A at IVS 4+1 was found in family I, and a novel insGAGGTGG mutation (c.703-709dup7bp) resulted in a frameshift (p.A237Gfsx13) in family II. CONCLUSION: We are able to add a new mutation of MEN1 gene in Chinese patients with MEN1 that will be useful for the diagnosis and treatment of the disease.

OBJETIVO: O objetivo deste estudo foi identificar as mutações em duas famílias chinesas com NEM1. SUJEITOS E MÉTODOS: Três membros das duas famílias chinesas foram estudados. Em todos eles, as regiões codificadoras e sequências adjacentes do gene MEN1 foram amplificadas e sequenciadas. RESULTADOS: Uma alteração heterozigota recorrente de T>A em IVS 4+1 foi encontrada na família I, e uma nova mutação insGAGGTGG (c.703-709dup7bp) levou a um frameshift (p.A237Gfsx13) na família II. CONCLUSÃO: Adicionou-se uma nova mutação ao gene MEN1 em pacientes chineses com diagnóstico de NEM1 que vai ser útil no diagnóstico e tratamento da doença.

Intron 9 of MEN1 gene mutation-induced multiple endocrine neoplasia type 1 : one case and analysis of his pedigree / 中华内分泌代谢杂志

To study the MEN1 gene mutations in a multiple endocrine neoplasia type 1 ( MEN 1 ) family,and determine the possible mechanism of disease induced by the mutations.Genomic DNA was isolated from peripheral blood leukocytes and the MEN1-related tumor tissues of the patient and the family members,then the coding exons and exon/intron boundaries of the MEN1 gene were amplified by polymerase chain reaction (PCR) and sequenced.Subclone sequencing was performed to identify the heterozygosity.Further immunohistochemistry was performed to observe menin protein expression in the tumor tissues.We identified a heterozygous deletion mutation of intron 9 ( IVS9+ 1_11 delGTGAGGGACAG) in the proband and two family menbers.We also demonstrated for the first time that the expression of menin protein is absent in the parathyroid adenoma tissue.The heterozygous mutation in the initial of intron 9,IVS9+ 1_11 delGTGAGGGACAG is a new type of MEN1 gene mutations in China.This mutation may produce an aberrant splicing of MEN1 mRNA,generating easily degradation and loss of expression of menin protein and resulting eventually in the disease.

The impact of clinical and genetic screenings on the management of the multiple endocrine neoplasia type 1

PURPOSE: To perform clinical and genetic screening for multiple endocrine neoplasia type 1 (MEN1) in patients at the Academic Hospital of the University of São Paulo School of Medicine, and to analyze its impact on clinical management of patients with MEN1. METHODS: The clinical diagnosis of MEN1 was made in accordance with the Consensus on multiple endocrine neoplasias. Mutation analysis of the entire MEN1 tumor suppressor gene and genetic screening of at-risk family members were performed by direct sequencing. To analyze the implementation of genetic diagnosis, the studied patients were separated into 3 groups: MEN1 index cases (group I), clinically diagnosed MEN1 cases (group II), and genetically diagnosed MEN1 cases (group III). RESULTS: In total, 154 individuals were clinically and genetically studied. We identified 12 different MEN1 mutations. Fifty-two MEN1 cases were identified: 13 in group I, 28 in group II, and 11 in group III. The mean age in group III (27.0 years) was significantly lower than in groups I (39.5 years) and II (42.4 years; P = 0.03 and P = 0.01, respectively). Patients in groups I and II mostly presented 2 or 3 MEN1-related tumors, while 81.8 percent of those in group III presented 1 or no MEN1-related tumor. Additionally, in group III, 45.4 percent of cases were asymptomatic, and no metastasis or death was verified. Surveillance for MEN1 mutations allowed the exclusion of 102 noncarriers, including a case of MEN1 phenocopy. CONCLUSION: Our data supports the benefits of clinical and genetic screening for multiple endocrine neoplasia type 1 in the management of this syndrome.

OBJETIVOS: Realizar rastreamentos clínico e gênico para Neoplasia Endócrina Múltipla tipo 1 (NEM1) e analisar seu impacto no seguimento clínico desses pacientes no Hospital das Clínicas, SP. MÉTODOS: O diagnóstico clínico de NEM1 foi realizado de acordo com o Consenso sobre neoplasias endócrinas múltiplas. A análise genética para identificação de mutações foi realizada por sequenciamento automático de todas as regiões codificadoras e fronteiras exon/intron do gene MEN1. Os casos afetados foram sub-divididos em 3 grupos e analisados separadamente: casos-índices (grupo I), familiares diagnosticados clinicamente (grupo II) e genicamente (grupo III). RESULTADOS: Um total de 154 casos participou desse estudo, sendo 52 diagnosticados com NEM1: 13 do grupo I, 28 do grupo II e 11 do grupo III. A idade média ao diagnóstico no grupo III (27 anos) foi significativamente menor que a dos grupos I (39,5 anos; p = 0,03) e II (42,4 anos; p = 0,01). A maioria dos pacientes dos grupos I e II apresentou 2 ou 3 tumores, enquanto que 81,8 por cento dos casos do grupo III apresentavam 1 ou nenhum tumor relacionado à NEM1. Além disto, 45,4 por cento dos casos do grupo III eram assintomáticos, não sendo observados nenhuma metástase ou óbito. Os demais 102 familiares sob-risco estudados não herdaram mutação MEN1 e foram excluídos do rastreamento clínico. Um caso de fenocópia NEM1 foi também localizado. DISCUSSÃO: Nossos dados demonstraram importantes benefícios no seguimento dos pacientes NEM1, obtidos pela implementação dos rastreamentos clínico e gênico para essa doença.

Two cases of MEN1 gene mutation-induced multiple endocrine neoplasia type 1 and analysis of their pedigrees / 中华内分泌代谢杂志

Objective To determine the relationship between MEN1 gene mutations and occurrence of multiple endocrine neoplasia type 1 and their inherited characteristics. Methods Genomic DNA was extracted from the peripheral blood lymphocytes of patients and other family members. PCR was performed to amplify all 10 exons of MEN1 gene. The PCR products were directly sequenced. Subclone sequencing was performed to identify the heterozygosity. Results An 18 base pairs of insertion(372-373 insACCTGTCTATCATCGCCG) was identified in one family and a 4 base pairs of deletion (357-360delCTGT) in the other family, both mutations occurred in exon 2 of MEN1 gene in the patients, and the former was a new mutation. Conclusion The MEN1 gene mutations were identified in two Chinese families with multiple endocrine neoplasia type 1, in one of which a novel mutation of MEN1 gene (372-373insACCTGTCTATCATCGCCG) was detected.