Multiple Endocrine Neoplasia Syndrome Type Research Articles

Comparison of 68Ga-Dotatate PET/CT and 18F-FDOPA PET/CT for the diagnosis of pancreatic neuroendocrine tumors in a MEN1 patient

ContextPancreatic neuroendocrine tumors (PNETs) occur in more than 80% of patients with multiple endocrine neoplasia type 1 (MEN1) syndrome, with predominance of small (<1cm) non-functioning tumors, followed by gastrinomas and insulinomas. Due to their small size, the diagnostic performance of conventional MRI and CT imaging is highly variable, with a real risk of false-negatives. Functional imaging on 111In-DTPA-Octreotide SPECT somatostatin receptor scintigraphy (Octreoscan®) is the modality of choice, but shows only 80% sensitivity. Alternatively, 18F-fluorodihydroxyphenylalanine (FDOPA) and, more recently, 68Ga-Dotatate PET/CT imaging are valuable options in case of negative Octreoscan®. Case reportA 55 old-year woman diagnosed with MEN1 syndrome, presented with multiple asymptomatic but progressive PNETs revealed on ultrasound endoscopy. Octreoscan® was negative, as was 18F-FDOPA PET/CT, whereas 68Ga-Dotatate PET/CT detected all PNETs found on endoscopy. ConclusionWe here report the first case of a MEN1 patient who successfully underwent a 68Ga-Dotatate PET/CT for detection and follow-up of PNETs, while both Octreoscan® and 18F-FDOPA PET/CT were negative.

Case report: optimal tumor cytoreduction and octreotide with durable disease control in a patient with MEN-1 and Zollinger-Ellison syndrome\u2014over a decade of follow-up

BackgroundZollinger-Ellison syndrome (ZES) is a rare condition characterized by hypersecretion of gastrin by gastrinoma tumors leading to severe peptic ulcer disease with potential development of gastric carcinoid tumors. Herein, we report the clinical course of a 68-year-old patient with multiple endocrine neoplasia type 1 (MEN-1) who underwent several surgeries to ultimately undergo optimal tumor cytoreduction of locally advanced gastrinomas and symptomatic gastric carcinoids. The patient was subsequently maintained on octreotide long-acting release (LAR). This case report supports consideration for aggressive tumor cytoreduction and octreotide in similar patients with MEN-1-associated ZES for durable disease control and symptom management.Case presentationThe patient is a 68-year-old male with multiple endocrine neoplasia type 1 (MEN-1), diagnosed in 1993 after presenting with recurrent renal calculi and hypercalcemia. Soon thereafter, he presented with symptoms and elevated gastrin levels suggestive of ZES prompting abdominal exploration with partial resection of the duodenum to remove gastrinoma tumor nodules. Within 4 years of the operation, he represented with intractable hypergastrinemia despite optimal medical management with peak gastrin levels exceeding 29,000 pg/mL, in 2006. In January 2007, the patient returned to the operating room for resection of regional peripancreatic and perigastric lymph nodes and enucleation of pancreatic body and tail gastrinoma tumors. Although his gastrin level decreased to 5000 pg/mL with resultant improvement of symptoms, in less than 2 years, he developed disease progression with obstructive symptomatology from enlarging gastric carcinoids and rising gastrin levels. In May of 2008, he underwent pancreaticoduodenectomy and near-total gastrectomy. Since June of 2008, the patient shows no demonstrable progression of disease and remains asymptomatic on LAR octreotide (30 mgs). Gastrin levels have been well controlled (range, 100–624 pg/mL; current 114 pg/mL).ConclusionSuccess of this procedure in our case report highlights the potential role for optimal tumor cytoreduction and LAR octreotide to control disease progression in a patient with MEN-I and Zollinger-Ellison syndrome with locally advanced gastrinoma and secondary large gastric carcinoids.

Multiple endocrine neoplasia type 1 in Poland: a two-centre experience.

Multiple endocrine neoplasia type 1 (MEN1) has been causing problems for clinicians since it was first described in 1954 by Wermer. Not only its rarity, but also its variable clinical manifestations and lack of genotype-phenotype correlation make it hard to establish evidence-based guidelines for the management of this syndrome. Nationwide registers and population-based research are the best means to improve knowledge about this rare disease. As yet, there is no example of such research in the Polish population of MEN1 patients. We performed a retrospective analysis of clinical and genetic data of patients diagnosed with MEN1 syndrome and followed-up in two polish referral centres in the years 1994-2018. We analysed 79 patients, of whom the majority were women. The mean age of the patient population was 43 years, mean age at MEN1 diagnosis was 37.95 years, and mean interval from initial symptoms to MEN1 diagnosis was 6.93 years. Primary hyperparathyroidism (PHP), gastroenteropancreatic neuroendocrine tumour (GEP-NET), and pituitary adenoma (PA) developed in 90%, 52%, and 47% of patients, respectively. The dominance of insulinoma with low prevalence of gastrinoma is the most vivid difference, when compared to previously described populations. Moreover, we found 3.5-fold higher risk of developing a pituitary tumour in patients with a frameshift mutation with the STOP codon of the MEN1 gene. The Polish population of patients with MEN1 is different than previously described European and Asian populations, primarily in prevalence of functional NETs. A frameshift mutation with the STOP codon of the MEN1 gene significantly increases the risk of PA. Further studies with a larger cohort of patients are needed to fully describe the Polish population and improve diagnosis and management of the syndrome.

First Reported Case of a Well-Differentiated Neuroendocrine Tumor (WDNET) Arising Within Diffuse Ganglioneuromatosis (DGN) in a Patient With Neurofibromatosis Type 1 (NF-1)

Abstract Case Report A 51-year-old female with NF-1 underwent flexible sigmoidoscopy, which revealed a 1.8-cm mass in the upper rectum. The noncircumferential mass was located predominantly at the posterior rectal wall and was suspicious for a neurofibroma. The biopsy revealed a WDNET arising in a ganglioneuroma that extended to the edges of the biopsy tissue. The patient underwent a segmental resection, and sections revealed residual grade 1 WDNET intimately admixed with DGN. The area of DGN also showed multifocal microscopic clusters of neuroendocrine cells limited to the lamina propria. Discussion NF-1 involves the gastrointestinal tract in 10% to 25% of affected individuals. DGN is a poorly circumscribed, frequently transmural gastrointestinal lesion composed of spindled and ganglion cells that may be seen in PTEN hamartomatous tumor syndrome, multiple endocrine neoplasia syndrome type 2B, and (less commonly) NF-1. Though malignant transformation of neurofibromas to malignant peripheral nerve sheath tumors is well documented in NF-1, malignant transformation of DGN is extremely rare. To our knowledge, this is the first reported case of a WDNET arising in DGN. In addition to being the first reported case of WDNET in this setting, this is the first case to describe microscopic neuroendocrine cell nests in DGN. Similar proliferations have been described in the setting of inflammatory bowel disease, termed microcarcinoid or neuroendocrine cell micronests, which are not thought to have malignant potential. However, given the presence of these microscopic neuroendocrine cell nests within the larger DGN lesions and adjacent to the WDNET, we hypothesize that in the setting of NF-1, microscopic neuroendocrine cell clusters may serve as a precursor of WDNET. While this is a rare situation, these novel findings should prompt careful examination for WDNET and microscopic neuroendocrine cell nests in future cases of DGN.

Risk factors of post-surgery complications in children with thyroid cancer

IntroductionThyroid cancer in children is a hot topic because of the large clinical heterogeneity and the risk of severe complications. We aimed to study 1. The frequency, 2. Etiology, and 3. Risk factors of post-surgery complications of thyroid cancer. Material and methodsA retrospective analysis including risk factors for post-surgery complications of patients treated for thyroid malignancies in years 2006–2018 was performed. ResultsOver a period of 12 years 22 patients with thyroid malignancy (68% female; 12.6 ± 4.0 years of age, median follow-up 6 years) were identified. Histologically, 12 (55%) patients had papillary carcinoma. Six patients (27.3%) had multiple endocrine neoplasia type 2 (MEN2) syndrome, 3 (13.7%) patients had medullary carcinoma and 1 patient had follicular carcinoma. Neck lymph node metastases were diagnosed in 8 (36.4%), distant metastases in 6 (27.3%), and both locations were involved in 4 (18.2%) patients. Six (27.3%) children had surgical complications: 1 child had unilateral vocal cord paralysis and transient hypoparathyroidism and 5 had transient hypoparathyroidism. The higher risk of surgery complications in forward stepwise logistic regression was associated in with distant metastases (R2 = 0.584, OR 52.63, p = 0.010). ConclusionsPostoperative complications were significantly associated with presence of distant metastases. Favorable results were observed in with children with MEN2 syndrome.

Molecular Mechanisms of Carcinogenesis Associated with MEN1 Gene Mutation

Despite recent advances in genomics and the discovery of numerous genes involved in carcinogenesis, the mechanisms of malignant transformation of different tissues remain poorly understood in most cases. This review presents the current knowledge on the role of the MEN1 gene and its protein product menin in the development of multiple endocrine neoplasia type 1 (MEN1), or Wermer’s syndrome. Here, we discuss the putative molecular and genetic mechanisms of carcinogenesis associated with the MEN1 gene mutation, as well as available and promising in vivo and in vitro models for studying the molecular basis of the disease. The lack of clear data on the role of the MEN1 gene in tumor initiation and progression in patients with MEN1 syndrome allows us to suggest two models for occurrence of malignant transformation in endocrine tissues.

The efficacy of everolimus and sunitinib in patients with sporadic or germline mutated metastatic pancreatic neuroendocrine tumors.

Hyperactivation of mTOR pathway and angiogenesis have been implicated in the pathogenesis of neuroendocrine tumors (NETs). Everolimus, an oral inhibitor of mTOR, and sunitinib, an antiangiogenic drug, are effective targeted therapies approved to treat locally advanced/metastatic pancreatic neuroendocrine tumors (pNETs). Most pNETs are sporadic and mutations in genes involved directly or indirectly in mTOR pathway regulation have been implicated, including somatic mutation in MEN1 in 44% of cases. About 10% of pNETs can be part of hereditary syndromes, e.g., multiple endocrine neoplasia type 1 (MEN1) and Von-Hippel Lindau (VHL), and these patients are underrepresented in pivotal phase III trials. We hypothesized that everolimus would be particularly effective in patients with MEN1-associated pNETs. Likewise, we inferred that sunitinib would also be beneficial to patients with VHL-associated pNETs. We conducted a multicenter retrospective and comparative study to assess the efficacy of everolimus and/or sunitinib in a cohort of patients with advanced pNETs with or without known MEN1 or VHL syndrome. The evaluation of the germline mutational status of VHL and MEN1 genes was retrospectively collected from the medical records. The primary endpoints were progression free survival (PFS) and time to treatment failure (TTF) of patients who received at least one month of sunitinib or everolimus in monotherapy. Thirty-three patients were identified from September 2009 to April 2018. Most were male 60.6%. Median Ki67 was 9%, liver metastases were present in 97%. The majority of tumors were non-functioning. Thirty-one patients received everolimus, of them 8 patients had germline mutations (6 in MEN1 and 2 in VHL genes). Nine patients received sunitinib, of them 3 had germline mutation (2 in MEN1 and 1 in VHL genes). In a median follow up of 26 months, among everolimus-treated patients, mTTF and mPFS were numerically superior in patients with germline mutations compared with those with sporadic pNETs (mTTF: 16.1 vs. 9.9 months, P=0.888; mPFS: 33.1 vs. 12.3 months, P=0.383). The disease control rate with everolimus was numerically higher in favor of germline mutated tumors compared to sporadic ones (87.5% vs. 68.4%). Sunitinib was used by 1 patient with VHL syndrome, achieving a PFS of 17.6 months. In the subgroup of sporadic pNETs, sunitinib was used by 6 patients reaching a mPFS of 18 months (range, 5-25 months), predominantly in second line. Our study suggests that everolimus may offer a prolonged tumor control in pNETS with germline mutations (MEN1 or VHL) compared to sporadic ones. The small number of patients and the retrospective nature of this study precludes any definitive conclusions.

Oncogene Panel Sequencing Analysis Identifies Candidate Actionable Genes in Advanced Well-Differentiated Gastroenteropancreatic Neuroendocrine Tumors

Objective: To report the rate of candidate actionable somatic mutations in patients with locally advanced and metastatic gastro-enteropancreatic (GEP) neuroendocrine tumors (NET) and of other genetic alterations that may be associated with tumorigenesis. Methods: A phase II mutation targeted therapy trial was conducted in patients with advanced well-differentiated G1/G2 GEP-NET. Mutations found in the mTOR pathway-associated genes led to treatment with the mTOR inhibitor everolimus, and were defined as actionable. Tumor deoxyribonucleic acid (DNA) from GEP-NET were sequenced and compared with germline DNA, using the OncoVAR-NET assay, designed for hybrid capture sequencing of 500 tumor suppressor genes and oncogenes. Somatic variants were called and copy-number (CN) variant analysis was performed. Results: Thirty patients (14 small-intestine, 8 pancreatic, 3 unknown primary NET, and 5 of other primary sites) harbored 37 lesions (4 patients had DNA of multiple lesions sequenced). Only 2 patients with sporadic NET (n = 26) had an actionable mutation leading to treatment with everolimus. Driver somatic mutations were detected in 18 of 30 patients (21/37 lesions sequenced). In the remaining samples without a driver mutation, CN alterations were found in 11/16 tumors (10/12 patients), including CN loss of chromosome (Chr) 18 (P<.05), CN gain of Chr 5, and loss of Chr 13. CN losses in Chr 18 were more common in patients without driver mutations detected. Pronounced genetic heterogeneity was detected in patients with multiple lesions sequenced. Conclusion: Genome-wide DNA sequencing may identify candidate actionable genes and lead to the identification of novel target genes for advanced well-differentiated GEP-NET. Abbreviations: Chr = chromosome; CN = copy number; DNA = deoxyribonucleic acid; FDA = Food and Drug Administration; GEP = gastro-enteropancreatic; MEN-1 = multiple endocrine neoplasia syndrome type 1; mTOR = mammalian target of rapamycin; NET = neuroendocrine tumor; PFS = progression-free survival; PNET = pancreatic neuroendocrine tumors; SINET = small-intestine neuroendocrine tumor.

Genetic predictors of insulin-producing pancreatic tumor

Insulinoma is the most common functioning tumor of the pancreas. Approximately 5% of its cases are associated with the multiple endocrine neoplasia syndrome type 1 (MEN1), caused by mutation in the MEN1 gene. MEN1 can be manifested by pituitary and parathyroid adenomas, pancreatic neuroendocrine tumors, tumors of the thyroid gland, adrenals, intestine, carcinoids of lungs and other organs. However, in 5–10% of the patients with clinical manifestation of this syndrome, MEN1 mutations cannot be identified. Moreover, the disease can be caused by various abnormalities (mutations, polymorphisms, etc.) in other genes. More than 30 genes, associated with insulin-producing pancreatic tumors, have been described in the literature. With a known germinal mutation, the prognosis and management of patients with insulinoma can be determined by the hereditary disease with which the tumor is associated. The article emphasizes the need to search for new genetic markers that predispose to the development of insulinoma. The necessity of extended genetic testing of patients with insulinomas is discussed, primarily of young patients with multifocal lesions, family history and associated disorders.

Management of primary hyperparathyroidism in pregnancy: a case series.

SummaryPrimary hyperparathyroidism (PHPT) is characterised by the overproduction of parathyroid hormone (PTH) due to parathyroid hyperplasia, adenoma or carcinoma and results in hypercalcaemia and a raised or inappropriately normal PTH. Symptoms of hypercalcaemia occur in 20% of patients and include fatigue, nausea, constipation, depression, renal impairment and cardiac arrythmias. In the most severe cases, uraemia, coma or cardiac arrest can result. Primary hyperparathyroidism in pregnancy is rare, with a reported incidence of 1%. Maternal and fetal/neonatal complications are estimated to occur in 67 and 80% of untreated cases respectively. Maternal complications include nephrolithiasis, pancreatitis, hyperemesis gravidarum, pre-eclampsia and hypercalcemic crises. Fetal complications include intrauterine growth restriction; preterm delivery and a three to five-fold increased risk of miscarriage. There is a direct relationship between the degree of severity of hypercalcaemia and miscarriage risk, with miscarriage being more common in those patients with a serum calcium greater than 2.85 mmol/L. Neonatal complications include hypocalcemia. Herein, we present a case series of three women who were diagnosed with primary hyperparathyroidism in pregnancy. Case 1 was diagnosed with multiple endocrine neoplasia type 1 (MEN1) in pregnancy and required a bilateral neck exploration and subtotal parathyroidectomy in the second trimester of her pregnancy due to symptomatic severe hypercalcaemia. Both case 2 and case 3 were diagnosed with primary hyperparathyroidism due to a parathyroid adenoma and required a unilateral parathyroidectomy in the second trimester. This case series highlights the work-up and the tailored management approach to patients with primary hyperparathyroidism in pregnancy.Learning points:Primary hyperparathyroidism in pregnancy is associated with a high incidence of associated maternal fetal and neonatal complications directly proportionate to degree of maternal serum calcium levels.Parathyroidectomy is the definitive treatment for primary hyperparathyroidism in pregnancy and was used in the management of all three cases in this series. It is recommended when serum calcium is persistently greater than 2.75 mmol/L and or for the management of maternal or fetal complications of hypercalcaemia. Surgical management, when necessary is ideally performed in the second trimester.Primary hyperparathyroidism is genetically determined in ~10% of cases, where the likelihood is increased in those under 40 years, where there is relevant family history and those with other related endocrinopathies. Genetic testing is a useful diagnostic adjunct and can guide treatment and management options for patients diagnosed with primary hyperparathyroidism in pregnancy, as described in case 1 in this series, who was diagnosed with MEN1 syndrome.Women of reproductive age with primary hyperparathyroidism need to be informed of the risks and complications associated with primary hyperparathyroidism in pregnancy and pregnancy should be deferred and or avoided until curative surgery has been performed and calcium levels have normalised.

Generation and characterization of Men1 mutant mouse models for studying MEN1 disease

Abstract Patients with multiple endocrine neoplasia type 1 (MEN1) mutations are predisposed to MEN1 syndrome affecting various endocrine cell lineages. Following its identification in the late 1990s, laboratories around the world, including our own, used gene-targeting approaches in murine models to study the MEN1 gene and its related diseases. Subsequently, this field of research witnessed an upsurge in the use of Men1 mutant mouse models to dissect MEN1 functions. These studies led to unraveling the natural history of MEN disease, and highlighted cellular and molecular mechanisms underlying the development of the disease. In this review, we present the currently available data concerning the generation and characterization of Men1 mutant mouse models in connection with MEN1 syndrome.

SUN-032 Exome Sequencing Reveals that Pathogenic RET Variants Occur at Higher Prevalence Than Previously Recognized: Data from a US Health System Biobank

Background: Multiple Endocrine Neoplasia Syndrome Type 2 (MEN2) is an inherited endocrine disorder characterized by the development of pheochromocytoma, medullary thyroid carcinoma (MTC) and parathyroid neoplasia. MEN2 is autosomal dominant and occurs from activating missense variants in the RET proto-oncogene. The estimated prevalence of MEN2 is thought to be 1 per 30,000 in the general population, and although rare, the identification of MEN2 can aid with early screening and prevention for patients and their families. Aim: The aim of our study was to investigate the prevalence and clinical manifestations of pathogenic RET variants in the multi-ethnic BioMe Biobank. Methods: We used exome sequencing and electronic health record (EHR) data from BioMe Biobank participants, who are recruited from primary care and specialty clinics across a single U.S. Health System. We evaluated exome sequence data from 30,000 BioMe participants for RET variants designated as pathogenic for MEN2 according to the clinical genetics database ClinVar. We reviewed EHR data for carriers of pathogenic RET variants. Results: In the BioMe Biobank, 5 ClinVar pathogenic variants were identified in the RET gene. Fifteen participants were heterozygous carriers of these variants; 5 were of self-reported African ancestry, 5 of Hispanic/Latino ancestry, 2 of European ancestry, and 3 of other or unknown ancestry. The age range of carriers was 23-78 years, and 60% were female. The estimated prevalence of pathogenic RET variant carriers in BioMe was ~1 in 2000. Based on EHRs, only 3 carriers (20%) were identified from usual clinical care as having the diagnosis of MEN2A. All 3 carriers with diagnosed MEN2A had the 10:43114500:T:C variant (rs75076352) and had a history of MTC and pheochromocytoma. One of the 3 carriers had a history of elevated parathyroid hormone levels and renal calculi without hypercalcemia. Two of the 3 carriers had a documented family history of MEN2A. Of the 12 pathogenic RET variant carriers without known MEN2, 9 (75%) were diagnosed with hypertension. 7 (58%) carried the 10:43119548:G:A variant (rs79658334). Of these 7 carriers, one had a thyroid nodule, three had autoimmune thyroid disease, one had an adrenal cortical adenoma with primary hyperaldosteronism and hypokalemic periodic paralysis, and two had no known endocrine conditions. Conclusions: These results from the BioMe Biobank reveal a higher prevalence of pathogenic RET variants than previously recognized. Carriers of pathogenic RET variants demonstrate highly variable expressivity for traits for which earlier diagnoses might improve outcomes; these findings have implications for cascade testing of family members. Genomic screening for pathogenic RET variants will likely improve our understanding of MEN2 on a more molecular basis.

MON-531 Pattern of Health-Related Quality of Life Six Months after Parathyroidectomy in Patients with Multiple Endocrine Neoplasia Type 1 and Main Modifying Factors

Background: Surgery is the elective therapy for primary hyperparathyroidism (HPT) in patients with multiple endocrine neoplasia type 1 (MEN1). As MEN1 mutation carriers invariably will develop HPT up to 50 years, the annual periodic screening have allowed an early diagnosis of HPT in MEN1 syndrome, frequently before manifestation of clinical symptoms. Health-related quality of life (HR-QoL) both before after parathyroidectomy (PTx) has been poorly described. As the ideal timing to indicate PTx is yet controversial and undefined and, most recently, the value of less extensive surgeries has been considered for some groups, data on HR-QoL may be useful to clarify better these conflicting issues. Objectives: To investigate post-operative HR-QoL aspects of patients submitted to PTx for MEN1-related HPT (HPT/MEN1). Methods: Prospective analysis of HPT/MEN1 patients submitted to total PTx with immediate forearm autograft (TPTx+A) or subtotal parathyroidectomy (SPTx) in single institution. A psychologist applied Short Form 36 Health Survey Questionnaire immediately before and 6 months after surgery. Changes of both Physical Component Summary Score (PCS) and Mental Component Summary Score (MCS) were analyzed considering persistence of HPT, hypoparathyroidism and pancreatectomy after the PTx. Results: Of 19 patients (mean age 38.4±14.4, 7 men), 8 underwent TPTx+A and 11 had SPTx. Overall, median (interquartiles ranges) of pre-operative PCS and MCS were 73.8 (50.0-88.0) and 65.0 (44.5-83.2), respectively. At 6 months, median PCS was 71.2 (55.8-91.0) and median MCS was 80.2 (46.8-88.0). There were five (4, PTxT+A; 1, SPTx) patients with postoperative hypoparathyroidism, one with persistent HPT (SPTx) and 13 with normal parathyroid function (4, TPTx+A; 9, SPTx) six months after PTx. PCS worsened in four cases with hypoparathyroidism (80%) and in five euparathyroid (36%), but without statistical significance (p, 0.14). MCS worsened in four cases with hypoparathyroidism (80%), but in only one euparathyroid (7%) (p, 0.0061). The worst decrease of both PCS and MCS occurred in two patients submitted to pancreatectomy during the follow-up after parathyroidectomy (PCS decreased 79% in one case and 53% in the other; MCS decreased 75% and 37%, respectively). Conclusion: Hypoparathyroidism worsens the HR-QoL after PTx in HPT/MEN1, particularly in patients undergoing subsequent pancreatectomy.

MON-328 Twenty-Year Follow-Up of a Patient with a Novel MEN1 Gene Mutation

Background: The multiple endocrine neoplasia type 1 (MEN1) syndrome is a rare autosomal dominant inherited tumor syndrome. Mutations in the MEN1 gene are detectable in approximately 70-90% of kindreds with classic MEN1 syndrome (1). We present the case of a patient with a novel MEN1 gene mutation. Clinical Case: A 41 year old Caucasian male with a diagnosis of MEN1 syndrome has been followed up in our clinic for 20 years. At the age of 21, he had two parathyroid glands resection for hypercalcemia which revealed an adenoma of the right superior parathyroid gland. He had one more parathyroid gland resected 6 months later for persistent hypercalcemia. Around that time, he also had appendectomy for suspected appendicitis and the pathology results showed a carcinoid tumor of the appendix. At the age of 33, he underwent total parathyroidectomy, thymectomy, and auto transplantation of half parathyroid gland in the left forearm for recurrent hypercalcemia. At the age of 39, he developed frequent hypoglycemic episodes with symptoms including confusion. Serum glucose levels of 20-30 mg/dL were documented during the episodes. A 72 hours fasting test showed a plasma glucose level of 53 mg/dL, with insulin level of 25.6 mU/L, proinsulin level of 5.2 pmol/L, C-peptide level of 5 ng/mL and low beta- hydroxybutyrate level. In response to 1 mg glucagon intravenous injection, plasma glucose level improved by 83 mg/dL in 30 minutes. He then had selective arterial calcium stimulation test and the results showed the insulin peak rising after stimulation in the splenic artery suggested that the lesion was in the body and tail of the pancreas. He had partial pancreatectomy for insulinoma, however, the pathology results were consistent with vasoactive intestinal polypeptide- producing tumor (VIPoma) rather than insulinoma. The serum tests also supported a diagnosis of VIPoma: the VIP levels were 96.3 pg/mL preoperatively and 65 pg/mL postoperatively. Notably, he had intermittent abdominal pain after food intake and chronic watery diarrhea 5-7 times a day before pancreatectomy, which resolved after the surgery. The patient underwent genetic screening for MEN1 mutations which revealed the presence of a novel germline deletion mutation in exon 8 (1078delC), resulting in frame shifting of its coded menin protein (Arg360fsX13). Conclusion: We describe a novel MEN1 gene mutation (1078delC) in a patient with typical clinical manifestations of MEN1 syndrome including parathyroid adenomas, appendix carcinoid tumor, VIPoma, and insulinoma. The concurrence of pancreatic VIPoma and insulinoma or the existence of a pancreatic neuroendocrine tumor co-producing insulin and VIP in MEN1 patients has not been reported previously. Reference: (1) Agarwal SK. The future: genetics advances in MEN1 therapeutic approaches and management strategies. Endocr Relat Cancer. 2017;24:T119-T134.

SUN-046 Identification of Clinical Predictors for Detection of Mutations in Multiple Endocrine Neoplasia Type 1

Context: Guidelines has systematically suggested genetic testing for a wide spectrum of phenotypes in order to confirm or exclude surely the diagnosis of multiple endocrine neoplasia type 1 (MEN1). However, the probability of find a germline MEN1 mutation has showed extremely variable (5-95%) when different phenotypes are considered. The prompt recognition of potential clinical predictors could anticipate the result of the genetic testing in the different clinical scenarios. Objective: To investigate if specific phenotypic features may predict the presence of germline MEN1 mutations in index-cases with clinical diagnosis of MEN1 syndrome. Methods and Patients: 110 MEN1 index cases were included: amplicons based on long-range PCR covering the full MEN1 open reading frame of 94 MEN1 index cases (49 familial, 45 sporadic) were sequenced by targeted-Next Generation Sequencing (tNGS) MiSeq Illumina platform while Sanger Sequencing (SS) was approached to the other 16 MEN1 index cases (2 familial, 14 sporadic). MLPA assay was supported to 31 MEN1-negative patients by tNGS/SS whose DNA samples were available. Results: 68 index cases (62%) had germline MEN1 mutations. With the tNGS/SS/MLPA protocol, the mutation detectability rate was higher in familial MEN1 (90%, 46/51 vs. 37%; 22/59; p, < 0.05). In comparison with MEN1-positive patients, MEN1-negative cases were older (53±12 vs. 39±13; p, < 0.05) and most of them had no more than two MEN1-related tumors (76%, 32/42 vs. 10%, 7/68; p, < 0.05). Considering the subset of 59 patients with negative familial history, the 22 MEN1-positive patients revealed clinical predictors for detection of MEN1 mutation when they were compared with 37 truly non-MEN1 mutation carriers. Thus, sporadic MEN1-positive patients had higher significantly prevalence of the following predictors. 1) ≥ 3 tumors, 86% (19/22) versus 11% (4/37); 2) PETs, 86% (19/22) versus 22% (8/37); 3) which were multifocal, 100% versus 1/8 (9%); 4) with frequent synchronic association of functioning and NF/PETs, 47% (9/19) versus 0% and; 5) high frequency of malignancies, 58% (11/19) versus 5% (2/37). Indeed, there was confirmation of these predictors comparing all 68 MEN1-positive carriers against 42 MEN1-negative cases. Conclusions: The strategy adopted to support the diagnosis of MEN1 based on analysis of clinical predictors and genetic testing for tNGS/SS-MLPA underscored that the positive familial history, occurrence of three or more MEN1 tumors, presence of PETs, especially multifocal PETs, and malignancies are strong predictors to detection of MEN1 mutations.

MON-320 Lost in the Rugae: High Grade Gastric Neuroendocrine Tumor in an MEN1 Patient with Zollinger-Ellison Syndrome

BACKGROUND: Gastric neuroendocrine tumors (carcinoid) associated with Zollinger Ellison Syndrome (ZES) induced hypergastrinemia in Multiple Endocrine Neoplasia type 1 (MEN1) occur in 15-50% of patients and are generally thought to be benign. Here we present a case of metastatic grade 3 gastric neuroendocrine tumor in MEN1. CASE: A 41-year male with history of MEN1 syndrome manifested by hyperparathyroidism, pancreatic neuroendocrine tumors, and Zollinger-Ellison Syndrome had been followed for 10 years. The patient had undergone yearly surveillance including CT, MRI, upper GI endoscopy (EGD) and 68Ga-DOTATATE, which had identified multiple small foci in the pancreas and duodenum. However, only MRI revealed a T2 hypointense 2.6 cm mildly enhancing mass along the lesser curvature of the stomach that was not visible on CT, MRI, EGD or 68Ga-DOTATATE within the 2 years prior. Gastrin levels remained <500 pg/mL during this time. EGD within 3 months prior to diagnosis demonstrated near complete suppression of acid (on omeprazole 120mg BID) confirmed with an acid output of 0 mEq/hr and no visible masses within the enlarged gastric folds. A follow-up 68Ga-DOTATATE scan identified an intraluminal mass on the medial aspect of the gastric wall (17.55 SUV). On review, the tumor was not able to be visualized on prior scans due to the diffuse ZES-induced hypertrophic gastric mucosa and poorly distended stomach. In addition, 18F-FDG-PET/CT scan demonstrated a faint but discrete photopenic defect associated with known mass in the gastric wall. The patient underwent surgical resection of a 3.5cm mass. Pathology demonstrated strong and diffusely positive synaptophysin and chromogranin A with Ki-67 labelling index (MIB-1) >20% and mitotic count >20 per 10 high powered fields. At the time of diagnosis, this lesion was histologically classified as well to moderately differentiated, high grade neuroendocrine carcinoma (Grade 3), large cell type. Loss of heterozygosity for the MEN1 gene at 11q13 was confirmed in the tumor. Monitoring with serial scans demonstrated right hepatic lobe metastasis by 1-year post-surgery. CONCLUSION: Previous reports of MEN1/ZES gastric carcinoid are associated with high gastrin levels, long disease duration, and are typically grade 1 or 2[i]. Special attention to identification of gastric mucosal nodules with well-controlled ZES is required as these lesions may rarely become malignant. Endnotes i Berna MJ, et al. A prospective study of gastric carcinoids and enterochromaffin-like cell changes in multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome: identification of risk factors. JCEM. 2008; 93(5):1582-91.

Solitary ganglioneuroma of the oropharynx

Mucosal neuromas, or ganglioneuromas, attract attention as a frequent component of multiple endocrine neoplasia (MEN) syndrome type 2B. The paper describes a clinical and morphological case of solitary oropharyngeal ganglioneuroma in a 60-year-old man, whose observation has not revealed its apparent association with the MEN syndrome.

Intraoperative Decision-Making and Technical Aspects of Parathyroidectomy in Young Patients With MEN1 Related Hyperparathyroidism.

One in 5,000 to 1 in 50,000 births have multiple endocrine neoplasia type 1 (MEN1). MEN1 is a hereditary syndrome clinically defined by the presence of two of the following endocrine tumors in the same patient: parathyroid adenomas, entero-pancreatic endocrine tumors and pituitary tumors. Most commonly, patients with MEN1 manifest primarily with signs and symptoms linked to primary hyperparathyroidism. By age 50, it is estimated that 100% of patients with MEN1 will have been diagnosed with primary hyperparathyroidism. These patients will need to undergo resection of their hyperfunctioning glands, however there is no clear consensus on which procedure to perform and when to perform it in these patients. In this original study we describe and explain the rational of our peri-operative approach and management at MD Anderson Cancer Center of MEN1 patients with hyperparathyroidism. This protocol includes preoperative evaluation, intraoperative decision-making and detailed surgical technique adopted for these patients' care. Additionally we review follow-up and disease management in instances of recurrent primary hyperparathyroidism in patients with MEN1 syndrome.

Current approaches to the morphological diagnosis of pancreatic neuroendocrine tumors and prediction of their clinical course based on the analysis of our own database

Aim:Combined clinical and morphological analysis of the pancreatic neuroendocrine tumor (pNET) spectrum according to the new World Health Organization classification: patient distribution, hormonal status, morphological grading, somatostatin receptor 2 (SSR2) and 5 (SSR5) expression, the choice of tissue-specific markers for the differential diagnosis of primary NET in the pancreas based on metastases with unknown primary tumor.Materials and methods:The study was performed with 472 tissue samples from pNETs taken from patients. Morphological analysis consisted of histological and immunohistochemical examination with a panel of antibodies to chromogranin A, synaptophysin, CD56, insulin, glucagon, somatostatin, gastrin, calcitonin, adrenocorticotropic hormone (ACTH), serotonin, pancreatic polypeptide, cytokeratins (CK) of a wide spectrum, CK7 and CK19, p53, Ki-67, SSR 2 and SSR5, PDX-1, Isl-1, and NESP-55.Results:In women, the prevalence of pNETS was 2.3 higher than in men (2.3:1). We were able to identify 299 (63.3%) insulinomas, 134 (28.4%) non-functioning NETs, 28 (5.9%) gastrinomas and 1.8% rare tumors (somatostatinomas, “calcitoninomas” and ACTH-producing). Metastatic tumors were found in 16.5% of the cases. Multiple endocrine neoplasia syndrome type 1 was confirmed in 11.9% of the pNET patients, and in 30.8% of those aged below 30 years. Multiple tumors (2 to 10) were found in 32 patients by the time of the diagnosis or occurred at 7 to 18 years after initial surgery. 28.3% of the tumors were CK19-positive, with 54.4% of them being metastatic. Insulinomas were least prone to metastasizing (5.7% of the cases), with 41.2% of them being CK19-positive. Metastases were found in 70.4, 66.7, 100, and 100% of gastrinomas, “calcitoninomas”, ACTH-producing, and somatostatinomas, respectively, with CK19-positivity found in 85.2, 66.7, 66.7, and 100% of these tumors. SSR2 expression was observed in all gastrinomas and “calcitoninomas”, in 90.5% of “glucagonomas”, 85.7% of PPomas, and 66.7% of somatostatinomas. SSR5 expression was significantly less frequent. 86.3% of the studied tumors were PDX-1-positive: all somatostatinomas, 97.4% of insulinomas, 92.3% of gastrinomas, 83.3% of PPomas, 80% of the non-functioning NETs. PDX-1-negativity was identified in all “calcitoninomas” and in 57.1% of the non-functioning “glucagonomas”. 83.3% and 90.9% of the pNETs were Isl-1 and NESP-55-positive, respectively.Conclusion:Combined morphological and immunohistochemical examination of pNETs allows for the correct diagnosis, assessment of their prognosis and choice of the most effective treatment. The malignancy grade of pNETs depends on the cell immunophenotype and is higher in the cases with co-expression of the markers of neuroendocrine and ductal differentiation (CK19), as well as with ectopic hormonal production.

Relapse of the pituitary adenoma with a change of its hormonal activity in a female patient with multiple endocrine neoplasia syndrome type 1

Multiple endocrine neoplasia syndrome type 1 (MEN1, Wermer's syndrome) is a group of heterogeneous inherited diseases, with its pathogenesis related to hyperplasia or neoplasms of several endocrine glands. This syndrome is characterized by autosomal dominant mode of inheritance, high penetrance and similar prevalence among males and females. Prevalence of MEN1 is estimated to be 1:100,000 of the population. An interesting feature of the presented clinical case is a relapse and transformation of pituitary tumor from a prolactin-secreting into the mixed one, with distinct compartments of ACTH- and prolactin-secreting, in a female patient with a family MEN1 syndrome, with involvement of the pancreas, parathyroid and pituitary glands. Her brother had a synchronous manifestation of the same types of tumors, except corticotropinoma. The presented clinical case highlights the necessity of a comprehensive and life-long follow-up of MEN1 patients for a timely detection of neoplasms and appropriate treatment.