French guidelines from the GTE, AFCE and ENDOCAN-RENATEN (Groupe d'étude des Tumeurs Endocrines/Association Francophone de Chirurgie Endocrinienne/Reseau national de prise en charge des tumeurs endocrines) for the screening, diagnosis and management of Multiple Endocrine Neoplasia Type 1

Case Report: A novel likely pathogenetic variant of the MEN1 gene in multiple endocrine neoplasia type 1

Background

Multiple endocrine neoplasia type 1 (MEN1) is a rare disease caused by mutations in the oncosuppressor gene MEN1 and characterized by co-occurrence of tumors of the parathyroid gland, pancreas, and pituitary gland. The clinical manifestations of MEN1 are varied, and misdiagnosis is common. The life expectancy of patients with untreated MEN1 is short. Here, we report a case of a 50-year-old patient with recurrent urinary calculi for more than 10 years who had a pancreatic neuroendocrine tumor and parathyroid adenoma. The patient received a definitive diagnosis of MEN1. We analyze his clinical characteristics and describe our approach to management.

Case Presentation

Laboratory tests showed high parathyroid hormone (PTH), high blood calcium, and low blood phosphorus levels and increased excretion of urinary calcium. Immunohistochemical analysis showed loss of menin expression in pancreatic tumor tissues. Testing of the MEN1 gene revealed a variant in exon 9 (c.1257_1268del, p.lle420_Trp423del).

Conclusion

The patient's clinical characteristics combined with the testing of the MEN1 gene, it implied the variant was a novel likely pathogenetic variant. For patients with recurrent urinary stones, we recommend measuring blood calcium and PTH, and if there are abnormalities, screening other endocrine glands to exclude the possibility of MEN1.

Tatton-Brown-Rahman syndrome: A new multiple endocrine neoplasia syndrome with intellectual disability?

We describe for the first time the case of a woman presenting with Tatton-Brown-Rahman syndrome (TBRS) and multiple endocrine neoplasia (MEN). She developed primary hyperparathyroidism at age 13, a pituitary cyst at age 14, adrenal tumor at age 21, and metastatic insulinoma at age 34. In addition, she showed intellectual disability, obesity, multiple lipomas, facial dysmorphia, hemihypertrophy and kyphoscoliosis. At age 35, genome analysis revealed a pathogenic de-novo heterozygous germline DNMT3A variant, while classic MEN syndromes were ruled out by targeted somatic and germline genetic testing. This case highlights not only the importance of genomic analysis in patients with multiple and atypical conditions, but also the need for a multidisciplinary approach for TBRS patients, including in adulthood, involving endocrinologists to enhance understanding and optimize monitoring of this syndrome.

American Association of Clinical Endocrinology Consensus Statement on Management of Multiple Endocrine Neoplasia Type 1

OBJECTIVE

This document presents the findings of the American Association of Clinical Endocrinology (AACE) on the diagnosis, management, and surveillance of patients with multiple endocrine neoplasia type 1 (MEN1) and associated tumors. The task force included a diverse group of experts in endocrinology, oncology, genetics, surgery, and patient representation. A comprehensive literature review was conducted to address key issues related to the evaluation, surveillance, and treatment of MEN1-related tumors.

METHODS

The task force, comprised of 9 members with expertise in endocrinology, surgery, medical oncology, genetics, and patient advocacy, collaborated to develop guidance for the evaluation, surveillance, and management of MEN1-associated tumors. Consensus was defined as ≤1 dissenting vote and significant majority as ≥75%. Relevant studies were identified through a literature review process, and consensus statements were based on the available evidence.

RESULTS

The task force deliberated on the surveillance, evaluation, and management of MEN1-related tumors including parathyroid, pituitary, and gastroenteropancreatic neuroendocrine tumors and other tumors of relevance. The document also addresses the indications for MEN1 genetic testing.

CONCLUSIONS

This consensus statement aims to offer evidence-informed guidance for health care providers involved in the care of patients with MEN1 and associated tumors. It provides guidance on diagnostic tools, genetic testing criteria, imaging techniques, surgical interventions, and posttreatment monitoring. The practical, patient-centered approach outlined in this document is intended to improve outcomes for individuals with MEN1 and other high-risk endocrine tumors.

Management of primary hyperparathyroidism in MEN1: From initial subtotal surgery to complex treatment of the remaining gland

Multiple endocrine neoplasia type 1 (MEN1) is a rare genetic disease with autosomal dominant transmission, which can cause various tumors, particularly endocrine, in a given patient. Primary hyperparathyroidism (PHPT) is the most common and earliest manifestation, leading to surgery before the age of 50 in most patients. Biological severity and renal and/or bone complications dictate the timing of parathyroid surgery. The objective is to correct hypercalcemia to prevent impact, while minimizing the risk of hypoparathyroidism. The most widely recommended procedure is subtotal parathyroidectomy (3 or 3.5 glands removed), with thymic horn resection via a cervical route. The development of imaging techniques, however, makes it possible to discuss partial surgery (resection of 1 or 2 glands) on a case-by-case basis depending on preoperative imaging and other elements such as patient age. Finally, hypercalcemia recurrence after initial surgery is a common feature of MEN1, and management of the remaining gland is challenging with various options: reoperation, calcimimetics and US-guided ablation or therapeutic abstention.

Multiple Endocrine Neoplasia Type 1 With Adrenal Cortical Adrenocortical Carcinoma: A 25-Year Follow-Up and Family Report

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant genetic disorder characterized by neoplasia of the parathyroid, pancreatic islets, and anterior pituitary. In this report, we present a family case in which the proband was diagnosed with prolactinoma 25 years ago. During the current hospitalization, the patient was diagnosed with insulinoma, primary hyperparathyroidism, and adrenocortical carcinoma. The final diagnosis was MEN1, confirmed by identifying a heterozygous mutation in the MEN1 gene through genetic testing. The proband's son also tested positive for the same MEN1 gene mutation, although he exhibited no clinical symptoms. MEN1 associated with adrenocortical carcinoma is exceptionally rare, carries a high malignancy risk, and has a poor prognosis. Genetic testing for the MEN1 gene is crucial for accurate diagnosis, while family screening is beneficial for early detection, timely treatment, and improving patient outcomes.

Chapter 5: The roles of genetics in primary hyperparathyroidism

Around 10% of cases of primary hyperparathyroidism are thought to be genetic in origin, some of which are part of a syndromic form such as multiple endocrine neoplasia types 1, 2A or 4 or hyperparathyroidism-jaw tumor syndrome, while the remainder are cases of isolated familial primary hyperparathyroidism. Recognition of these genetic forms is important to ensure appropriate management according to the gene and type of variant involved, but screening for a genetic cause is not justified in all patients presenting primary hyperparathyroidism. The indications for genetic analysis have made it possible to propose a decision tree that takes into account whether the presentation is familial or sporadic, syndromic or isolated, patient age, and histopathological type of parathyroid lesion. Thus, the first consensus recommendation is to propose genetic screening to any patient with a familial form of primary hyperparathyroidism (≥2 1st or 2nd degree relatives) or in syndromic presentation or a sporadic isolated presentation if the patient is under 50 years of age, or over 50 with a recurrent or multi-glandular form, carcinoma, atypical parathyroid tumor and/or loss of parafibromin expression. The panel of genes currently recommended for first-line treatment comprises MEN1, CDKN1B, CDC73, CASR, GNA11, AP2S1 and GCM2. Other genes may also be involved in familial primary hyperparathyroidism, but in a much more rarely and less consistently. The second recommendation is to propose genetic screening, up to and including whole-genome sequencing in the event of inconclusive panel analysis, to patients with proven familial primary hyperparathyroidism and/or pediatric onset. The role of the genetic practitioner is to interpret the sequencing data by categorizing the variants into 5 classes of pathogenicity. The aim of genetic analysis is to identify the genetic variant involved in the patient's phenotype, in order to make or refute a diagnosis of hereditary primary hyperparathyroidism, and to adapt management and monitoring. Appropriate genetic counseling should then be provided for patient and family.

Chapter 6: Syndromic primary hyperparathyroidism

Syndromic primary hyperparathyroidism has several features in common: younger age at diagnosis when compared with sporadic primary hyperparathyroidism, often synchronous or metachronous multi-glandular involvement, higher possibility of recurrence, association with other endocrine or extra-endocrine disorders, and suggestive family background with autosomal dominant inheritance. Hyperparathyroidism in multiple endocrine neoplasia type 1 is the most common syndromic hyperparathyroidism. It is often asymptomatic in adolescents and young adults, but may be responsible for recurrent lithiasis and/or bone loss. Hyperparathyroidism-jaw tumor syndrome is less frequent, but often immediately symptomatic, with higher blood calcium levels, and is sometimes associated with an atypic parathyroid tumor or parathyroid carcinoma. Hyperparathyroidism in multiple endocrine neoplasia type 2A is not at the forefront of the clinical picture, rarely revealing the disease, and often manifests with few symptoms. Multiple endocrine neoplasia type 4 is a more recently described entity, in which hyperparathyroidism seems to occur later and be less severe than in previous syndromes. In all cases, the indications and modalities of surgical treatment should be discussed in an expert center. The risk of recurrence after surgery, particularly high in multiple endocrine neoplasia type 1, requires long-term monitoring.

Chapter 15: Recurrent or persistent primary hyperparathyroidism, parathyromatosis

Persistent primary hyperparathyroidism is defined as the persistence or recurrence of hypercalcemia within 6 months of parathyroid surgery. Recurrent primary hyperparathyroidism is defined as the recurrence of primary hyperparathyroidism more than 6 months after an initially curative parathyroidectomy. In these situations, it is essential to rule out differential diagnoses, and in particular secondary hyperparathyroidism and familial hypocalciuric hypercalcemia. Failure to remove the pathological parathyroid gland or glands during initial surgery for primary hyperparathyroidism is the most common situation in non-expert centers. In other situations, genetically determined multi-glandular primary hyperparathyroidism must be screened for. More rarely, a second sporadic adenoma is identified, or, exceptionally, a parathyroid carcinoma or parathyromatosis. Effective morphological evaluation, combining a morphological and functional imaging, is essential prior to any new parathyroid surgery. The indications for surgery must be discussed in a multidisciplinary team, assessing the risk/benefit ratio, since the risk of surgical complications is higher. Revision surgery should be performed using a suitable approach, after laryngoscopy, in an expert center, ideally with intraoperative PTH measurement and recurrent nerve neuromonitoring.

Progress report on multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) syndrome is an autosomal dominant disorder caused by a germline pathogenic variant in the MEN1 tumor suppressor gene. Patients with MEN1 have a high risk for primary hyperparathyroidism (PHPT) with a penetrance of nearly 100%, pituitary adenomas (PitAd) in 40% of patients, and neuroendocrine neoplasms (NEN) of the pancreas (40% of patients), duodenum, lung, and thymus. Increased MEN1-related mortality is mainly related to duodenal-pancreatic and thymic NEN. Management of PHPT differs from that of patients with sporadic disease, as the surgical approach in MEN1-related PHPT includes near-total or total parathyroidectomy because of multigland hyperplasia in most patients and the consequent high risk of recurrence. NEN management also differs from patients with sporadic disease due to multiple synchronous and metasynchronous neoplasms. In addition, the lifelong risk of developing NEN requires special considerations to avoid excessive surgeries and to minimize damage to the patient's function and well-being. This progress report will outline current insights into surveillance and management of the major clinical manifestation of MEN1 syndrome in children and adults with MEN1 diagnosis. In addition, we will discuss MEN1-like clinical presentation with negative MEN1-genetic workup and future clinical and research directions.

18F-Fluorocholine-Positron Emission Tomography/Computerized Tomography (FCH PET/CT) Imaging for Detecting Abnormal Parathyroid Glands: Indication, Practice, Interpretation and Diagnostic Performance

In patients with confirmed hyperparathyroidism (HPT) scheduled for surgical treatment, the preoperatory imaging permits to optimize the operatory protocol of parathyroidectomy (PTX), in particular by selecting those patients who can benefit from minimally invasive PTX (MIPTX). The MIPTX has the merit to shorten the operative time, incision length, and to reduce the operatory risks. With preoperative localization studies, the rate of PTX failure, in particular due to nonsuspected multiglandular or ectopic disease, has been profoundly decreased. The first cases of incidental localization of abnormal parathyroid glands (PTs) on FCH PET/CTs performed for another indication were reported more than one decade ago. Since then, significant amount of data from heterogeneous series of patients consistently confirmed better diagnostic performances of FCH PET/CT (sensitivity for detection of abnormal PT 97%, range 96%-98%) in comparison with other radiopharmaceuticals, ultrasonography or 4D-CeCT in localizing hyperfunctioning parathyroid glands (HFPTGs) in case of primary HPT. Utility of FCH PET/CT in case of renal HPT has been reported in fewer series. The article discusses and summarizes the bibliographic evidence on documented indications of FCH PET/CT in patients with HPT, its safety profile, the practice of FCH PET/CT and interpretation of FCH PET/CT findings, including potential interpretation pitfalls and tips to avoid them. Our real-world experience over 12 years reinforces published evidence supporting the use of FCH PET/CT as the first-line radionuclide imaging technique in patients with all types of HPT in whom surgery is an option.

Case report: Novel germline c.587delA pathogenic variant in familial multiple endocrine neoplasia type 1

Multiple Endocrine Neoplasia type 1 (MEN1) is a rare genetic disease, characterized by co-occurrence of several lesions of the endocrine system. In MEN1, the pathogenic MEN1 gene mutations lead to the Abnormal expression of menin, a critical tumor suppressor protein. We here reported a case of a 14-year-old male with insulinoma and primary hyperparathyroidism. Genetic testing demonstrated a novel heterozygote variant c.587delA of MEN1, resulting in the substitution of the 196th amino acid, changing from glutamic acid to glycine, followed by a frameshift translation of 33 amino acids. An identical variant was identified in the proband's father, who was further diagnosed with hyperparathyroidism. To the best of our knowledge, this is the first report of MEN1 syndrome caused by the c.587delA MEN1 variant. Observations indicated that, despite sharing the same MEN1 gene change, family members exhibited diverse clinical phenotypes. This underscored the presence of genetic anticipation within the familial context.

Familial states of primary hyperparathyroidism: an update

BACKGROUND

Familial primary hyperparathyroidism (PHPT) includes syndromic and non-syndromic disorders. The former are characterized by the occurrence of PHPT in association with extra-parathyroid manifestations and includes multiple endocrine neoplasia (MEN) types 1, 2, and 4 syndromes, and hyperparathyroidism-jaw tumor (HPT-JT). The latter consists of familial hypocalciuric hypercalcemia (FHH) types 1, 2 and 3, neonatal severe primary hyperparathyroidism (NSHPT), and familial isolated primary hyperparathyroidism (FIHP). The familial forms of PHPT show different levels of PHPT penetrance, developing earlier and with multiglandular involvement compared to sporadic counterpart. All these diseases exhibit Mendelian inheritance patterns, and for most of them, the genes responsible have been identified. DNA testing for predisposing mutations is helpful in index cases or in individuals with a high suspicion of the disease. Early recognition of hereditary disorders of PHPT is of great importance for the best clinical and surgical approach. Genetic testing is useful in routine clinical practice because it will also involve appropriate screening for extra-parathyroidal manifestations related to the syndrome as well as the identification of asymptomatic carriers of the mutation.

PURPOSE

The aim of the review is to discuss the current knowledge on the clinical and genetic profile of these disorders along with the importance of genetic testing in clinical practice.

Unlocking the Genetic Secrets of Acromegaly: Exploring the Role of Genetics in a Rare Disorder

Acromegaly is a rare endocrine disorder characterized by the excessive production of growth hormone (GH) in adulthood. Currently, it is understood that certain pituitary neuroendocrine tumors (PitNETs) exhibit a hereditary predisposition. These tumors' genetic patterns fall into two categories: isolated and syndromic tumors. The isolated forms are characterized by molecular defects that predispose exclusively to PitNETs, including familial isolated pituitary adenomas (FIPAs) and sporadic genetic defects not characterized by hereditary predisposition. All the categories involve either germline or somatic mutations, or both, each associated with varying levels of penetrance and different phenotypes. This highlights the importance of genetic testing and the need for a more comprehensive view of the whole disease. Despite the availability of multiple treatment options, diagnosis often occurs after several years, and management is still difficult. Early detection and intervention are crucial for preventing complications and enhancing the quality of life for affected individuals. This review aims to elucidate the molecular, clinical, and histological characteristics of GH-secreting PitNETs, providing insights into their prevalence, treatment nuances, and the benefits of genetic testing for each type of genetic disorder associated with acromegaly.

Multiple Endocrine Neoplasia Type 1

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1) is a rare genetic disease of autosomal dominant inheritance, with an estimated prevalence of 3-20/100 000. Its main feature is neuroendocrine neoplasia in the parathyroid glands, the endocrine pancreas, the duodenum, and the pituitary gland. In this article, we review the diagnostic and therapeutic options for MEN1-associated tumors.

METHODS

We present an analysis and evaluation of retrospective case studies retrieved from PubMed, guidelines from Germany and abroad, and our own experience.

RESULTS

The disease is caused by mutations in the MEN1 gene. Mutation carriers should participate in a regular, specialized screening program from their twenties onward. The early diagnosis and individualized treatment of MEN1-associated tumors can prevent the development of life-threatening hormonal syndromes and prolong the expected life span of MEN1 patients from 55 to 70 years, as well as improving their quality of life. Surgical treatment is based on the location, size, growth dynamics, and functional activity of the tumors. The evidence for treatment strategies is derived from retrospective studies only (level III evidence) and the optimal treatment is often a matter of debate. This is a further reason for treatment in specialized centers.

CONCLUSION

MEN1 is a rare disease, and, consequently, the evidence base for its treatment is limited. Carriers of disease-causing mutations in the MEN1 gene should be cared for in specialized interdisciplinary centers, so that any appreciable tumor growth or hormonal activity can be detected early and organ-sparing treatment can be provided.

A Cohort Study of CNS Tumors in Multiple Endocrine Neoplasia Type 1

PURPOSE

Multiple endocrine neoplasia type 1 (MEN1) is thought to increase the risk of meningioma and ependymoma. Thus, we aimed to describe the frequency, incidence, and specific clinical and histological features of central nervous system (CNS) tumors in the MEN1 population (except pituitary tumors).

EXPERIMENTAL DESIGN

The study population included patients harboring CNS tumors diagnosed with MEN1 syndrome after 1990 and followed up in the French MEN1 national cohort. The standardized incidence ratio (SIR) was calculated based on the French Gironde CNS Tumor Registry. Genomic analyses were performed on somatic DNA from seven CNS tumors, including meningiomas and ependymomas from patients with MEN1, and then on 50 sporadic meningiomas and ependymomas.

RESULTS

A total of 29 CNS tumors were found among the 1,498 symptomatic patients (2%; incidence = 47.4/100,000 person-years; SIR = 4.5), including 12 meningiomas (0.8%; incidence = 16.2/100,000; SIR = 2.5), 8 ependymomas (0.5%; incidence = 10.8/100,000; SIR = 17.6), 5 astrocytomas (0.3%; incidence = 6.7/100,000; SIR = 5.8), and 4 schwannomas (0.3%; incidence = 5.4/100,000; SIR = 12.7). Meningiomas in patients with MEN1 were benign, mostly meningothelial, with 11 years earlier onset compared with the sporadic population and an F/M ratio of 1/1. Spinal and cranial ependymomas were mostly classified as World Health Organization grade 2. A biallelic MEN1 inactivation was observed in 4/5 ependymomas and 1/2 meningiomas from patients with MEN1, whereas MEN1 deletion in one allele was present in 3/41 and 0/9 sporadic meningiomas and ependymomas, respectively.

CONCLUSIONS

The incidence of each CNS tumor was higher in the MEN1 population than in the French general population. Meningiomas and ependymomas should be considered part of the MEN1 syndrome, but somatic molecular data are missing to conclude for astrocytomas and schwannomas.