Multiple endocrine neoplasia (MEN) syndromes

Prospective Genetic Screening in Multiple Endocrine Neoplasia Syndromes

Multiple endocrine neoplasia syndromes are a rare but potentially fatal pathology due to the lack of early diagnosis. We have performed a narrative review of the medical literature, summarizing the main clinical concepts useful in current clinical practice, showing the importance of screening and early diagnosis during childhood.

Role of Nutrition in the Management of Patients with Multiple Endocrine Neoplasia Type 1

Multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome caused by inactivating mutations in the MEN1 tumor suppressor gene. The three main clinical manifestations of MEN1 are primary hyperparathyroidism (PHPT), duodenal-pancreatic neuroendocrine tumors (DP-NETs) and anterior pituitary tumors. Endocrine tumors in patients with MEN1 differ from sporadic tumors because of their younger age at onset, common multiple presentations and the different clinical course. MEN1 is characterized by a complex clinical phenotype; thus, patients should be followed by a multidisciplinary team of experts that includes an endocrinologist, a surgeon, a oncologist, a radiotherapist, and not least, a nutritionist. It is important to remember the fundamental role that diet plays as a primary prevention tool, together with a healthy and active lifestyle in preventing osteoporosis/osteopenia and reducing the risk of developing kidney stones due to hypercalciuria, two frequent clinical complications in MEN1 patients. Is very important for MEN1 patients to have an adequate intake of calcium, vitamin D, magnesium and phosphate to maintain good bone health. The intake of foods containing oxalates must also be kept under control because in combination with calcium they concur to form calcium oxalate crystals, increasing the risk of nephrolithiasis. Another aspect to consider is the management of patients with pancreatic neuroendocrine tumors undergoing major surgical resections of the pancreas that can lead to alterations in digestion and absorption mechanisms due to partial or total reduction in pancreatic enzymes such as amylase, lipase, and protease, resulting in malabsorption and malnutrition. Therefore, the nutritionist's aim should be to devise a dietary plan that takes into consideration each single patient, educating them about a healthy and active lifestyle, and accompanying them through various life stages by implementing strategies that can enhance their quality of life.

Multiple endocrine neoplasia type 2 (MEN2) and RET specific modifications of the ACMG/AMP variant classification guidelines and impact on the MEN2 RET database

The Multiple Endocrine Neoplasia type 2 (MEN2) RET proto-oncogene database, originally published in 2008, is a comprehensive repository of all publicly available RET gene variations associated with MEN2 syndromes. The variant-specific genotype/phenotype information, age of earliest reported medullary thyroid carcinoma (MTC) onset, and relevant references with a brief summary of findings are cataloged. The ACMG/AMP 2015 consensus statement on variant classification was modified specifically for MEN2 syndromes and RET variants using ClinGen sequence variant interpretation working group recommendations and ClinGen expert panel manuscripts, as well as manuscripts from the American Thyroid Association Guidelines Task Force on Medullary Thyroid Carcinoma and other MEN2 RET literature. The classifications for the 166 single unique variants in the MEN2 RET database were reanalyzed using the MEN2 RET specifically modified ACMG/AMP classification guidelines (version 1). Applying these guidelines added two new variant classifications to the database (likely benign and likely pathogenic) and resulted in clinically significant classification changes (e.g., from pathogenic to uncertain) in 15.7% (26/166) of the original variants. Of those clinically significant changes, the highest percentage of changes, 46.2% (12/26), were changes from uncertain to benign or likely benign. The modified ACMG/AMP criteria with MEN2 RET specifications will optimize and standardize RET variant classifications.

Unique Finding of a Primary Central Nervous System Neuroendocrine Carcinoma in a 5-Year-Old Child: A Case Report

Neuroendocrine tumors (NETs) are rare neoplasms predominantly arising in the gastrointestinal-tract or the lungs of adults. To date, only ten cases of primary central nervous system (CNS) NETs have been reported, with just three of them describing a neuroendocrine carcinoma (NECA) and none occurring in a child. We report on a previously healthy 5-year-old boy, who presented with headaches, nausea and vomiting, and was diagnosed with a left cerebellar solid mass with a cystic component. After gross-total resection, histology revealed a neuroendocrine carcinoma. Molecular analysis of the tumor tissue showed a KRAS-splice-site mutation (c451-3C > T). The KRAS-mutation was discovered to be a maternal germline mutation, previously described as likely benign. After extensive search for an extracranial primary tumor, including Ga-68 DOTANOC-PET-CT, the diagnosis of a primary CNS NECA was established, and proton irradiation was performed. Unfortunately, the patient developed an in-field recurrence just 5 weeks after the end of radiotherapy. The tumor was re-resected with vital tumor tissue. Six cycles of chemotherapy were initiated, consisting of cisplatin, carboplatin, etoposide and ifosfamide. The patient remains disease free 22 months after the end of treatment, supporting the beneficial effect of platinum- and etoposide-based chemotherapy for this tumor entity.

A narrative review of multiple endocrine neoplasia syndromes: genetics, clinical features, imaging findings, and diagnosis

Objective

We aimed to provide ideas for clinicians, especially radiologists, for the diagnosis of multiple endocrine neoplasia (MEN) syndromes.

Background

MEN syndromes include MEN1, MEN2, and MEN4 and usually involve 2 or more endocrine tumors. The MEN syndromes are a group of euchromatic dominant genetic diseases, and the main genes involved include MEN1 (MEN1), RET (MEN2), and CDKN1B (MEN4).

Methods

In this article, involving 8 cases (4 cases of MEN1, 2 cases of MEN2A, 1 case of MEN2B, 1 case of MEN4) from our center, we introduced the disease spectrum, clinical manifestations (especially imaging findings), and related genes involved in each type of MEN syndromes. We also discussed the differential diagnosis between MEN and sporadic tumors and emphasized that MEN should be screened and the relevant required examinations.

Conclusions

Considering that MEN syndromes involve multiple endocrine gland tumors and nonendocrine organ diseases, it is very important to identify potential patients early and perform multiple examinations on them, including biochemical and multitype, and multisite imaging examinations according to the disease spectrum of each type. Considering that this is a group of genetic diseases, both interviewing patients about their family history and genetic testing are also very important. Only in this way can a comprehensive and accurate diagnosis be made, enabling patients to receive appropriate treatment and improve their prognosis.

Patients' perception on the quality of care for multiple endocrine neoplasia disorders in Europe: an online survey from a patient support group

PURPOSE

European Patient Advocacy Groups (ePAGs) within the Endo-ERN identified a lack of knowledge about quality of care (QoC) of patients with multiple endocrine neoplasia (MEN). The aim of this study was to identify inequalities in care and to encourage improvements.

METHODS

The European MEN Alliance (EMENA) developed and conducted a survey, using the European Commissions' EUSurvey platform. Patient groups and healthcare professionals (HCPs) distributed the survey.

RESULTS

A total of 288 participants completed the survey (MEN1 n = 203, MEN2 n = 67, MEN3 n = 18) from 18 European countries. The majority of respondents were recruited via patient groups (58%), aged between 41 and 60 years (53%) and were female (67%). All participants reported having been diagnosed on average 5.58 years (95%-CI: 4.45-6.60) after first symptoms occurred. This timeframe was lower in the group with MEN2 (2.97 years, 95%-CI: 1.37-4.57). Most of the participants (67%) received their diagnosis by a positive gene test after presenting with one or more MEN-related tumours. Overall QoC was rated as either "good" (43%) or "excellent" (36%).

CONCLUSION

The results of this unique Europe-wide, patient-driven survey on QoC of patients with MEN show that ratings for overall QoC were lower than ratings for different aspects of care. This may be because of the complex nature of care for genetic syndromes. Furthermore, patients who connect with patient groups may be deemed "expert patients" whose answers are not representative of the overall MEN patient community. We hope that Endo-ERN can support further education and training for HCPs based on these results.

Comprehensive Analysis of MEN1 Mutations and Their Role in Cancer

Simple Summary

Cancers are characterized by accumulation of genetic mutations in key cell cycle regulators that alter or disable the function of these genes. Such mutations can be inherited or arise spontaneously during the life of the individual. The MEN1 gene prevents uncontrolled cell division and it is considered a tumor suppressor. Inherited MEN1 mutations are associated with certain parathyroid and pancreatic syndromes while spontaneous mutations have been detected in cancer cells. We investigated whether inherited mutations appear in cancer cells which would suggest that patients with parathyroid and pancreatic syndromes have a predisposition to develop cancer. We find a weak correlation between the spectrum of inherited mutations and those appearing spontaneously. Thus, inherited MEN1 mutations may not be a good predictor of tumorigenesis.

Abstract

MENIN is a scaffold protein encoded by the MEN1 gene that functions in multiple biological processes, including cell proliferation, migration, gene expression, and DNA damage repair. MEN1 is a tumor suppressor gene, and mutations that disrupts MEN1 function are common to many tumor types. Mutations within MEN1 may also be inherited (germline). Many of these inherited mutations are associated with a number of pathogenic syndromes of the parathyroid and pancreas, and some also predispose patients to hyperplasia. In this study, we cataloged the reported germline mutations from the ClinVar database and compared them with the somatic mutations detected in cancers from the Catalogue of Somatic Mutations in Cancer (COSMIC) database. We then used statistical software to determine the probability of mutations being pathogenic or driver. Our data show that many confirmed germline mutations do not appear in tumor samples. Thus, most mutations that disable MEN1 function in tumors are somatic in nature. Furthermore, of the germline mutations that do appear in tumors, only a fraction has the potential to be pathogenic or driver mutations.

Biomarkers for Pancreatic Neuroendocrine Neoplasms (PanNENs) Management-An Updated Review

Pancreatic neuroendocrine tumors (PanNENs) are rare sporadic cancers or develop as part of hereditary syndromes. PanNENs can be both functioning and non-functioning based on whether they produce bioactive peptides. Some PanNENs are well differentiated while others-poorly. Symptoms, thus, depend on both oncological and hormonal causes. PanNEN diagnosis and treatment benefit from and in some instances are guided by biomarker monitoring. However, plasmatic monoanalytes are only suggestive of PanNEN pathological status and their positivity is typically followed by deepen diagnostic analyses through imaging techniques. There is a strong need for new biomarkers and follow-up modalities aimed to improve the outcome of PanNEN patients. Liquid biopsy follow-up, i.e., sequential analysis on tumor biomarkers in body fluids offers a great potential, that need to be substantiated by additional studies focusing on the specific markers and the timing of the analyses. This review provides the most updated panorama on PanNEN biomarkers.

Genodermatoses with malignant potential

The hereditary nature of some forms of cancer was recognized long ago. Over time, recognition of associated findings led to the delineation of numerous hereditary cancer syndromes. Many of these syndromes also have cutaneous manifestations, the recognition of which can lead to their early identification. Recognition of these syndromes allows vigilant surveillance and preemptive treatment, which can dramatically impact the risks of morbidity and mortality for affected patients. The rise of rapid and accurate genetic testing now allows the early identification of asymptomatic at risk family members so that monitoring can be initiated as early as possible. The dermatologist plays a critical role in early identification of these syndromes and, in many cases, their treatment. This review summarizes many known hereditary cancer syndromes with cutaneous findings, their etiology, identification, evaluation, and management. Importantly, this is an ever evolving topic and new findings and syndromes will continue to be recognized. The dermatologist must be always alert to ensure they are detected.

Genetics and Epigenetics of Gastroenteropancreatic Neuroendocrine Neoplasms

Gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs) are heterogeneous regarding site of origin, biological behavior, and malignant potential. There has been a rapid increase in data publication during the last 10 years, mainly driven by high-throughput studies on pancreatic and small intestinal neuroendocrine tumors (NETs). This review summarizes the present knowledge on genetic and epigenetic alterations. We integrated the available information from each compartment to give a pathway-based overview. This provided a summary of the critical alterations sustaining neoplastic cells. It also highlighted similarities and differences across anatomical locations and points that need further investigation. GEP-NENs include well-differentiated NETs and poorly differentiated neuroendocrine carcinomas (NECs). NENs are graded as G1, G2, or G3 based on mitotic count and/or Ki-67 labeling index, NECs are G3 by definition. The distinction between NETs and NECs is also linked to their genetic background, as TP53 and RB1 inactivation in NECs set them apart from NETs. A large number of genetic and epigenetic alterations have been reported. Recurrent changes have been traced back to a reduced number of core pathways, including DNA damage repair, cell cycle regulation, and phosphatidylinositol 3-kinase/mammalian target of rapamycin signaling. In pancreatic tumors, chromatin remodeling/histone methylation and telomere alteration are also affected. However, also owing to the paucity of disease models, further research is necessary to fully integrate and functionalize data on deregulated pathways to recapitulate the large heterogeneity of behaviors displayed by these tumors. This is expected to impact diagnostics, prognostic stratification, and planning of personalized therapy.

First Case of Mature Teratoma and Yolk Sac Testis Tumor Associated to Inherited MEN-1 Syndrome

Introduction: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominantly inherited endocrine tumor syndrome characterized by the development of cancer in various endocrine organs, particularly in the pituitary, parathyroid and pancreas. Moreover, in some cases, also non-endocrine tumors can be diagnosed, developing atypical phenotypes. Case report: We report herein the clinical history of a patient affected by MEN-1 syndrome who developed atypical features for this disease. The patient's clinical history started in August 2015 when he was referred, at the age of 23 years, to the Emergency Department of our Hospital for the occurrence of progressive asthenia, weakness, tremors and syncope. The biochemical test documented hyper-calcemia and severe hypoglycemia. The patient was referred to our Neuroendocrine Tumor and Pituitary Unit and he was diagnosed with pancreatic insulinoma, hypercalcemic hyperparathyroidism, and a prolactin secreting pituitary adenoma. The MEN-1 syndrome was suspected and genetic tests for mutation of menin resulted positive for the pathogenic variant c1548dupG. In January 2016, the patient was diagnosed with intratubular germ cell neoplasia, consisting of a mature teratoma and yolk sac tumor and he underwent a right orchiectomy. Conclusion: This is the first case report showing the clear association of MEN-1 syndrome with yolk sac tumors and teratomas, as in our case, the c1548dupG represents a pathogenic variant rather than a SNP. This case suggests the opportunity of an accurate evaluation of the testis particularly in young MEN-1 affected patients and that a prompt screening for neoplastic disease should involve all the endocrine glands.

Multiple endocrine neoplasia-like syndrome in 24 baboons (Papio spp.)

Multiple endocrine neoplasia (MEN) has not been reported in baboons, but this condition is well described in humans. An internal database was searched for all cases of concurrent endocrine hyperplasia and neoplasia in baboons. Twenty-four baboons (Papio spp.) with concurrent endocrine hyperplasia and neoplasia were identified. Twenty-one baboons had lesions in two endocrine organs, two baboons had lesions in three organs, and one baboon had lesions in four organs. Ten baboons aligned with the MEN1 classification; 14 baboons did not match any current human MEN classification. We report 24 cases of MEN-like syndrome in baboons. MEN1-like lesions accounted for nearly half (41%) of the affected animals. Genetic analysis of baboons with MEN-like syndrome could further elucidate the mechanisms of MEN and support the use of baboons as animal models for human MEN.

Integrating surgery and genetic testing for the modern surgeon

The field of cancer genetics is rapidly evolving and several genetic mutations have been identified in hereditary cancer syndromes. These mutations can be diagnosed via routine genetic testing allowing prompt intervention. This is especially true for certain variants of colorectal, breast, and thyroid cancers where genetic testing may guide surgical therapy. Ultimately, surgical intervention may drastically diminish disease manifestation or progression in individuals deemed as high-risk based on their genetic makeup. Understanding the concepts of gene-based testing and integrating into current surgical practice is crucial. This review addresses common genetic syndromes, tests, and interventions salient to the current surgeon.

Identification of intestinal ganglioneuromatosis leads to early diagnosis of MEN2B: role of rectal biopsy

BACKGROUND/PURPOSE

Gastrointestinal symptoms are very common in patients with multiple endocrine neoplasia type 2B (MEN2B) syndrome. Herein, we present a case of intestinal ganglioneuromatosis (IGN) in MEN2B syndrome and a systematic literature review with a special focus on gastrointestinal symptoms prior to the diagnosis of MEN2B.

METHODS

Literature search was performed (years 1966-2015) using the "Pubmed" and "Scopus" databases. Search terms used were gastrointestinal, intestinal and MEN2B.

RESULTS

Literature search revealed 188 publications on MEN2B patients with gastrointestinal symptoms, providing a total of 55 patients including our own case. The far most common gastrointestinal symptom was constipation (72.7%). The onset of gastrointestinal symptoms occurred in 29 out of 55 cases (52.3%) below the age of 1year. However, MEN2B diagnosis was established at a median age of 13.0years (range 0-46years). The histological finding of IGN led to the diagnosis of MEN2B In 15 of 55 patients (27.3%) at a median age of 3years (range 0-31years).

CONCLUSION

Paying close attention to gastrointestinal problems in early childhood and taking a rectal biopsy that precisely screens for IGN offers the chance of diagnosing MEN2B syndrome early in infancy.

Sporadic Insulinoma Presenting as Early Morning Night Terrors

A 16-year-old boy with a recent diagnosis of night terrors was evaluated for recurrent early morning hypoglycemia after an early morning seizure. Evaluation in clinic with critical laboratories identified hyperinsulinemic hypoglycemia. Additional investigation revealed a sporadic insulinoma as the etiology of his hypoglycemia and all symptoms were resolved after pancreaticoduodenectomy. The importance of obtaining critical laboratory samples is highlighted and appropriate radiologic, medical, and pathologic testing is discussed. We additionally review the medical and surgical management of hyperinsulinemic hypoglycemia. A discussion of multiple endocrine neoplasia type 1 associated insulinomas is included as well. This case highlights the importance of considering hypoglycemia in the evaluation of night terrors and new-onset seizures.

miR-24 Inhibition Increases Menin Expression and Decreases Cholangiocarcinoma Proliferation

Menin (MEN1) is a tumor-suppressor protein in neuroendocrine tissue. Therefore, we tested the novel hypothesis that menin regulates cholangiocarcinoma proliferation. Menin and miR-24 expression levels were measured in the following intrahepatic and extrahepatic cholangiocarcinoma (CCA) cell lines, Mz-ChA-1, TFK-1, SG231, CCLP, HuCCT-1, and HuH-28, as well as the nonmalignant human intrahepatic biliary line, H69. miR-24 miRNA and menin protein levels were manipulated in vitro in Mz-ChA-1 cell lines. Markers of proliferation and angiogenesis (Ki-67, vascular endothelial growth factors A/C, vascular endothelial growth factor receptors 2/3, angiopoietin 1/2, and angiopoietin receptors 1/2) were evaluated. Mz-ChA-1 cells were injected into the flanks of nude mice and treated with miR-24 inhibitor or inhibitor scramble. Menin expression was decreased in advanced CCA specimens, whereas miR-24 expression was increased in CCA. Menin overexpression decreased proliferation, angiogenesis, migration, and invasion. Inhibition of miR-24 increased menin protein expression while decreasing proliferation, angiogenesis, migration, and invasion. miR-24 was shown to negatively regulate menin expression by luciferase assay. Tumor burden and expression of proliferative and angiogenic markers was decreased in the miR-24 inhibited tumor group compared to controls. Interestingly, treated tumors were more fibrotic than the control group. miR-24-dependent expression of menin may be important in the regulation of nonmalignant and CCA proliferation and may be an additional therapeutic tool for managing CCA progression.

Multiple Endocrine Neoplasia Syndromes: A Comprehensive Imaging Review

MEN1, MEN2, and MEN4 comprise a series of familial disorders involving the simultaneous occurrence of tumors in more than one endocrine organ, collectively known as multiple endocrine neoplasia. Patients with this family of disorders develop tumors of the parathyroid gland, pancreas, pituitary gland, adrenal gland, and thyroid gland, along with miscellaneous neuroendocrine tumors of the respiratory and gastrointestinal tracts. Although some patients undergo early prophylactic surgical management, particularly in the setting of familial medullary thyroid carcinoma, many develop tumors later in life. These tumors are often discovered at imaging for screening purposes. Recognition of the imaging features of the known tumors is important for appropriate patient management.

Animal models of multiple endocrine neoplasia

Multiple endocrine neoplasia (MEN) syndromes are autosomal dominant diseases with high penetrance characterized by proliferative lesions (usually hyperplasia or adenoma) arising in at least two endocrine tissues. Four different MEN syndromes have been so far identified: MEN type 1 (MEN1), MEN2A (also referred to as MEN2), MEN2B (or MEN3) and MEN4, which have slightly varying tumor spectra and are caused by mutations in different genes. MEN1 associates with loss-of-function mutations in the MEN1 gene encoding the tumor suppressor menin. The MEN2A and MEN2B syndromes are due to activating mutations in the proto-oncogene RET (Rearranged in Transfection) and are characterized by different phenotypic features of the affected patients. MEN4 was the most recent addition to the family of the MEN syndromes. It was discovered less than 10 years ago thanks to studies of a rat strain that spontaneously develops multiple endocrine tumors (named MENX). These studies identified an inactivating mutation in the Cdkn1b gene, encoding the putative tumor suppressor p27, as the causative mutation of the rat syndrome. Subsequently, germline mutations in the human ortholog CDKN1B were also found in a subset of patients with a MEN-like phenotype and this led to the identification of MEN4. Small animal models have been instrumental in understanding important biochemical, physiological and pathological processes of cancer onset and spread in intact living organisms. Moreover, they have provided us with insight into gene function(s) and molecular mechanisms of disease progression. We here review the currently available animal models of MEN syndromes and their impact on the elucidation of the pathophysiology of these diseases, with a special focus on the rat MENX syndrome that we have been characterizing.

Pediatric intestinal motility disorders

Pediatric intestinal motility disorders affect many children and thus not only impose a significant impact on pediatric health care in general but also on the quality of life of the affected patient. Furthermore, some of these conditions might also have implications for adulthood. Pediatric intestinal motility disorders frequently present as chronic constipation in toddler age children. Most of these conditions are functional, meaning that constipation does not have an organic etiology, but in 5% of the cases, an underlying, clearly organic disorder can be identified. Patients with organic causes for intestinal motility disorders usually present in early infancy or even right after birth. The most striking clinical feature of children with severe intestinal motility disorders is the delayed passage of meconium in the newborn period. This sign is highly indicative of the presence of Hirschsprung disease (HD), which is the most frequent congenital disorder of intestinal motility. HD is a rare but important congenital disease and the most significant entity of pediatric intestinal motility disorders. The etiology and pathogenesis of HD have been extensively studied over the last several decades. A defect in neural crest derived cell migration has been proven as an underlying cause of HD, leading to an aganglionic distal end of the gut. Numerous basic science and clinical research related studies have been conducted to better diagnose and treat HD. Resection of the aganglionic bowel remains the gold standard for treatment of HD. Most recent studies show, at least experimentally, the possibility of a stem cell based therapy for HD. This editorial also includes rare causes of pediatric intestinal motility disorders such as hypoganglionosis, dysganglionosis, chronic intestinal pseudo-obstruction and ganglioneuromatosis in multiple endocrine metaplasia. Underlying organic pathologies are rare in pediatric intestinal motility disorders but must be recognized as early as possible.