Clinical aspects of multiple endocrine neoplasia type 1

Evaluation and Surgical Management of Multiple Endocrine Neoplasias

Multiple endocrine neoplasia (MEN) syndromes are rare autosomal dominant diseases that are associated with a mixture of both endocrine and non-endocrine tumors. Traditionally, there are 2 types of MEN that have unique clinical associations: MEN 1 (parathyroid hyperplasia, pancreatic neuroendocrine tumors, and pituitary tumors) and MEN 2 (medullary thyroid carcinoma and pheochromocytoma), which is further classified into MEN 2A (adds parathyroid adenomas) and 2B (adds ganglioneuromas and marfanoid habitus). Many of the endocrine tumors are resected surgically, and the pre, intra, and postoperative management strategies used must take into account the high recurrence rates asscioated with MEN tumors.

Early detection of multiple endocrine neoplasia type 1: A case report

BACKGROUND

Multiple endocrine neoplasias (MENs) are a group of hereditary diseases involving multiple endocrine glands, and their prevalence is low. MEN type 1 (MEN1) has diverse clinical manifestations, mainly involving the parathyroid glands, gastrointestinal tract, pancreas and pituitary gland, making it easy to miss the clinical diagnosis.

CASE SUMMARY

We present the case of a patient in whom MEN1 was detected early. A middle-aged male with recurrent abdominal pain and diarrhea was admitted to the hospital. Blood tests at admission revealed hypercalcemia and hypophosphatemia, and emission computed tomography of the parathyroid glands revealed a hyperfunctioning parathyroid lesion. Gastroscopy findings suggested a duodenal bulge and ulceration. Ultrasound endoscopy revealed a hypoechoic lesion in the duodenal bulb. Further blood tests revealed elevated levels of serum gastrin. Surgery was performed, and pathological analysis of the surgical specimens revealed a parathyroid adenoma after parathyroidectomy and a neuroendocrine tumor after duodenal bulbectomy. The time from onset to the definitive diagnosis of MEN1 was only approximately 1 year.

CONCLUSION

For patients who present with gastrointestinal symptoms accompanied by hypercalcemia and hypophosphatemia, clinicians need to be alert to the possibility of MEN1.

Beyond MEN1, When to Think About MEN4? Retrospective Study on 5600 Patients in the French Population and Literature Review

CONTEXT

Germline CDKN1B variants predispose patients to multiple endocrine neoplasia type 4 (MEN4), a rare MEN1-like syndrome, with <100 reported cases since its discovery in 2006. Although CDKN1B mutations are frequently suggested to explain cases of genetically negative MEN1, the prevalence and phenotype of MEN4 patients is poorly known, and genetic counseling is unclear.

OBJECTIVE

To evaluate the prevalence of MEN4 in MEN1-suspected patients and characterize the phenotype of MEN4 patients.

DESIGN

Retrospective observational nationwide study. Narrative review of literature and variant class reassessment.

PATIENTS

We included all adult patients with class 3/4/5 CDKN1B variants identified by the laboratories from the French Oncogenetic Network on Neuroendocrine Tumors network between 2015 and 2022 through germline genetic testing for MEN1 suspicion. After class reassessment, we compared the phenotype of symptomatic patients with class 4/5 CDKN1B variants (ie, with genetically confirmed MEN4 diagnosis) in our series and in literature with 66 matched MEN1 patients from the UMD-MEN1 database.

RESULTS

From 5600 MEN1-suspected patients analyzed, 4 with class 4/5 CDKN1B variant were found (0.07%). They presented with multiple duodenal NET, primary hyperparathyroidism (PHPT) and adrenal nodule, isolated PHPT, PHPT, and pancreatic neuroendocrine tumor. We listed 29 patients with CDKN1B class 4/5 variants from the literature. Compared with matched MEN1 patients, MEN4 patients presented lower NET incidence and older age at PHPT diagnosis.

CONCLUSION

The prevalence of MEN4 is low. PHPT and pituitary adenoma represent the main associated lesions, NETs are rare. Our results suggest a milder and later phenotype than in MEN1. Our observations will help to improve genetic counseling and management of MEN4 families.

Lipomatoses

Lipomatoses are benign proliferation of adipose tissue. Lipomas (benign fat tumors) are the most common component of lipomatosis. They may be unique or multiple, encapsulated or not, subcutaneous or sometimes visceral. In some cases, they form large areas of non-encapsulated fat hypertrophy, with a variable degree of fibrosis. They can develop despite the absence of obesity. They may be familial or acquired. At difference with lipodystrophy syndromes, they are not associated with lipoatrophy areas, except in some rare cases such as type 2 familial partial lipodystrophy syndromes (FPLD2). Their metabolic impact is variable in part depending on associated obesity. They may have functional or aesthetic consequences. Lipomatosis may be isolated, be part of a syndrome, or may be visceral. Isolated lipomatoses include multiple symmetrical lipomatosis (Madelung disease or Launois-Bensaude syndrome), familial multiple lipomatosis, the painful Dercum's disease also called Adiposis Dolorosa or Ander syndrome, mesosomatic lipomatosis also called Roch-Leri lipomatosis, familial angiolipomatosis, lipedema and hibernomas. Syndromic lipomatoses include PIK3CA-related disorders, Cowden/PTEN hamartomas-tumor syndrome, some lipodystrophy syndromes, and mitochondrial diseases, especially MERRF, multiple endocrine neoplasia type 1, neurofibromatosis type 1, Wilson disease, Pai or Haberland syndromes. Finally, visceral lipomatoses have been reported in numerous organs and sites: pancreatic, adrenal, abdominal, epidural, mediastinal, epicardial… The aim of this review is to present the main types of lipomatosis and their physiopathological component, when it is known.

Successful management of a multiple endocrine neoplasia type 1-associated thymic neuroendocrine neoplasms with acute chest pain as initial symptom: A rare case report

Key Clinical Message

Acute chest pain can be the first manifestation of multiple endocrine neoplasia type 1(MEN1)-associated thymic neuroendocrine neoplasms (NEN). Comprehensive treatment may be an effective strategy for MEN1-associated NEN.

Abstract

Multiple endocrine neoplasia type 1(MEN1)-associated thymic neuroendocrine neoplasms (NEN) is caused by the mutation of tumor suppressor MEN1 gene. Patients with MEN1-associated NEN initially presenting with acute chest pain are very rare. In the manuscript, we reported a case of a 45-year-old man who developed MEN1-associated NEN with acute chest pain as initial symptom. Thoracoscopic thymotomy was performed and thymic NEN was successfully removed. Genetic test showed a germline mutation of MEN1 gene in this patient. Immunohistochemical staining exhibited Syn(+), CgA(+), INSM1(+), CD56(+) and Ki67-positive cells (2%) in MEN1-associated NEN. Further evaluation unveiled MEN1-associated benign tumors including digestive NEN and pituitary gland adenoma. The 99mTc-HYNIC-TOC scintigraphy showed that focally increased radioactivity in the mid-upper abdomen. This patient was administered with 50Gy/25F of radiation dose to treat the postoperative lesions. Subsequently, sandostatin LAR (30 mg per week) was used as systemic therapy. He had no recurrence or metastasis for 6-month follow-up. Thus, acute chest pain can be the first manifestation of MEN1-associated NEN, and comprehensive treatment including surgery, radiation and systemic treatment may be an effective strategy for MEN1-associated NEN.

Multiple neuroendocrine tumors in the stomach, duodenum and pancreas of a MEN1 patient

Gastrinoma, a common type of GEP-NENs, is often sporadic, rarely manifested as multiple endocrine neoplasia type 1 (MEN1). We described a rare case of MEN1-related gastrinomas in the stomach, duodenum and pancreas along with lymph node metastases. The female patient had a long history of recurrent abdominal pain and diarrhea. G1 neuroendocrine tumors were diagnosed by endoscopic biopsy in the pylorus, duodenal bulb and the neck of the pancreas successively. Her symptoms lessened and serum gastrin level decreased after surgery. This case will help us learn more about MEN1-associated patients who are confirmed with multiple neuroendocrine tumors.

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.

Challenges in genetic screening for inherited endocrinopathy affecting the thyroid, parathyroid and adrenal glands in Singapore

Significant progress has been made in the understand-ing of many human diseases, especially cancers, which has contributed to improved and increased survival. The Human Genome Project and The Cancer Genome Atlas project brought about a new era, with an understanding of inherited diseases at a molecular level, which subsequently facilitated the option of precision medicine. Precision medicine has helped tailor treatment decisions at an individual level, for instance in terms of surgical treatments or targeted therapies in advanced diseases. Despite the increasing advances in genetic-lead precision medicine, this has not translated into increasing uptake among patients. Reasons for this may be potential knowledge gaps among clinicians; on reasons for poor uptake of genetic testing such as for cultural, religious or personal beliefs; and on financial implications such as lack of support from insurance companies. In this review, we look at the current scenario of genetic screening for common inherited endocrine conditions affecting the thyroid, parathyroid and adrenal glands in Singapore, and the implications associated with it.

Differential Diagnosis of Solid Pancreatic Lesions Using Detective Flow Imaging Endoscopic Ultrasonography

The differential diagnosis of solid pancreatic lesions (SPLs) using B-mode endoscopic ultrasonography (EUS) is challenging. Detective flow imaging (DFI) offers the potential for detecting low-flow vessels in the pancreas, thus enhancing diagnostic accuracy. This retrospective study aimed to investigate DFI-EUS findings of SPLs and analyze their differential diagnostic accuracy for pancreatic cancer. We included 104 patients with pathologically confirmed SPLs who underwent EUS between April 2021 and June 2023. Expert endosonographers, blinded to the patients' clinical data, evaluated images obtained through B-mode, eFLOW, and DFI-EUS. The frame rate and vessel detection sensitivity were compared between eFLOW and DFI, and the diagnostic criteria for pancreatic cancer were established. The visualization rate for vessels in SPLs was significantly higher with DFI-EUS (96%) compared to eFLOW (27%). Additionally, DFI showed a superior frame rate, sensitivity (99%), and accuracy (88%) for detecting pancreatic cancer, although with a modest specificity (43%). On DFI-EUS, characteristics such as hypovascularity, peritumoral vessel distribution, or spotty vessel form were suggestive of pancreatic cancer. DFI-EUS significantly improved the visualization of vascular structures within the SPLs, highlighting its efficacy as a diagnostic modality for pancreatic cancer.

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.

Updates on the genetics of multiple endocrine neoplasia

Multiple endocrine neoplasia (MEN) is a group of syndromes with a genetic predisposition to the appearance of endocrine tumors, and shows autosomal dominant transmission. The advent of molecular genetics has led to improvements in the management of MEN in terms of diagnosis, prognosis and therapy. The genetics of MEN is the subject of regular updates, which will be presented throughout this paper. MEN1, the first to be described, is associated with the MEN1 gene. MEN1 is well known in terms of the observed phenotype, with genetic analysis being conclusive in 90% of patients with a typical phenotype, but is negative in around 10% of families with MEN1. Improvement in analysis techniques and the identification of other genes responsable for phenocopies allows the resolution of some, but not all, cases, notably non-familial forms suspected to be fortuitous assocations with tumors. MEN4 is a rare phenocopy of MEN1 linked to constitutional mutations in the CDKN1B gene. Though it closely resembles the phenotype of MEN1, published data suggests the appearance of tumors is later and less frequent in MEN4. MEN2, which results from mutations in the RET oncogene, shows a strong genotype-phenotype correlation. This correlation is particularly evident in the major manifestation of MEN2, medullary thyroid carcinoma (MTC), in which disease aggressiveness is dependent on the pathogenic variant of RET. However, recent studies cast doubt on this correlation between MTC and pathogenic variant. Lastly, the recent description of families carrying a mutation in MAX, which is known to predispose to the development of pheochromocytoma and paraganglioma, and presents a phenotypic spectrum that evokes MEN, suggests the existence of another syndrome, MEN5.

Performance of [18F]fluorocholine PET/CT in MEN1-related primary hyperparathyroidism before initial surgery or for persistent/recurrent disease

PURPOSE

The aims of the study were to evaluate the performance and robustness of [18F]fluorocholine PET/CT in detecting hyperfunctioning parathyroid glands in MEN1-related primary hyperparathyroidism (pHPT) at different stages of their disease.

METHODS

Retrospective French multicenter study including patients with MEN1 pHPT who underwent [18F]fluorocholine PET/CT at initial diagnosis or for evaluation of persistent/recurrent disease. PET/CT were independently reviewed by two readers in a blinded manner. The assessment of PET/CT on a per-patient basis was assessed using a comprehensive set of criteria that considered pathological findings or agreement with alternative diagnostic methods in non-operated patients. The secondary objectives included the analysis of the performance of PET/CT at a per-lesion level, with reference to a pathological Gold Standard, and examining its interobserver reproducibility.

RESULTS

A total of 71 MEN1 patients were included (73 PET/CT) in the study. At the per-patient level (entire cohort), [18F]fluorocholine PET/CT sensitivity ranged from 98.5 to 100% among the different readers. An average of 1.77 glands per PET was described, with 2.35 glands at the initial diagnosis (n = 23) and 1.5 in previously operated cases (n = 50). PET/CT detected more lesions than conventional imaging work-up (neck ultrasound and/or scintigraphy). At the per-lesion level (41 operated patients), sensitivity ranged across different readers from 84.4 to 87%, and specificity ranged from 94.7 to 98.8%. At initial diagnosis, all patients that exhibited 3 or more abnormal glands on PET underwent subtotal parathyroidectomy while 7 out of 13 patients with 1 or 2 gland abnormalities on PET underwent less than subtotal parathyroidectomy. Finally, the degree of inter-observer agreement was high.

CONCLUSION

[18F]fluorocholine PET/CT is a reliable and robust imaging modality for the evaluation of MEN1-related pHPT and could guide surgeons in achieving the optimal benefit-risk ratio. This study gives a great impetus for its adoption as a primary diagnostic tool in this context.

Genetics of hereditary forms of primary hyperparathyroidism

Primary hyperparathyroidism (PHPT), a relatively common disorder characterized by hypercalcemia with raised or inappropriately normal serum parathyroid hormone (PTH) concentrations, may occur as part of a hereditary syndromic disorder or as a non-syndromic disease. The associated syndromic disorders include multiple endocrine neoplasia types 1-5 (MEN1-5) and hyperparathyroidism with jaw tumor (HPT-JT) syndromes, and the non-syndromic forms include familial hypocalciuric hypercalcemia types 1-3 (FHH1-3), familial isolated hyperparathyroidism (FIHP), and neonatal severe hyperparathyroidism (NS-HPT). Such hereditary forms may occur in > 10% of patients with PHPT, and their recognition is important for implementation of gene-specific screening protocols and investigations for other associated tumors. Syndromic PHPT tends to be multifocal and multiglandular with most patients requiring parathyroidectomy with the aim of limiting end-organ damage associated with hypercalcemia, particularly osteoporosis, nephrolithiasis, and renal failure. Some patients with non-syndromic PHPT may have mutations of the MEN1 gene or the calcium-sensing receptor (CASR), whose loss of function mutations usually cause FHH1, a disorder associated with mild hypercalcemia and may follow a benign clinical course. Measurement of the urinary calcium-to-creatinine ratio clearance (UCCR) may help to distinguish patients with FHH from those with PHPT, as the majority of FHH patients have low urinary calcium excretion (UCCR < 0.01). Once genetic testing confirms a hereditary cause of PHPT, further genetic testing can be offered to the patients' relatives and subsequent screening can be carried out in these affected family members, which prevents inappropriate testing in normal individuals.

[Comparative analysis of bone complications/manifestations in sporadic and MEN1-related primary hyperparathyroidism]

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1) - is a rare syndrome with an autosomal dominant inheritance pattern caused by a mutation in the tumor suppressor gene (MEN1). Parathyroid involvement is the most common MEN1 manifestation resulting in primary hyperparathyroidism (mPHPT). Data on the prevalence and structure of bone disease in mPHPT compared to sporadic one (sPHPT) are often incomplete and contradictory.

AIM

The purpose of this study was to compare the severity of bone involvement between mPHPT and sPHPT.

MATERIALS AND METHODS

A single-center retrospective study was conducted among young patients in the active phase of PHPT and without prior parathyroidectomy in anamnesis. The analysis included the main parameters of calcium-phosphorus metabolism, bone remodeling markers, as well as an assessment of disease complications. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA) at sites of lumbar spine, femur and radius. Trabecular bone score (TBS) was applied to estimate trabecular microarchitecture. All patients included in the study underwent genetic testing.

RESULTS

Group 1 (mPHPT) included 26 patients, and group 2 (sSHPT) included 30 age-matched patients: the median age in group 1 was 34.5 years [25; 39], in group 2 - 30.5 years [28; 36], (p=0.439, U-test). Within group 1, the subgroup 1A (n=21) was formed with patients without other hormone-produced neuroendocrine neoplasms (NEN) in the gastrointestinal tract (GI) and the anterior pituitary gland. The duration of PHPT was comparable in both groups: mPHPT - 1 year [0; 3] versus sPHPT - 1 year [0; 1], (p=0.533, U-test). There were no differences in the main parameters of calcium-phosphorus metabolism, as well as in the prevalence of kidney complications. In the mPHPT group, bone abnormalities were observed significantly more often compared to sPHPT: 54 vs 10% (p=<0.001; F-test). Statistically significant differences were revealed both in BMD and in Z-score values of the femoral neck and total hip, which were lower in the mPHPT group. These differences remained significant when comparing subgroup 1A with sPHPT.

CONCLUSION

MEN1-associated PHPT may be accompanied by a more severe decrease in BMD in the femoral neck and total hip compared to sPHPT regardless of the other hormone-producing NEN. Clarifying the role of mutation in the MEN1 gene in these processes requires further study.

Recurrence After Surgery for Primary Hyperparathyroidism in 517 Patients With Multiple Endocrine Neoplasia Type 1: An Association Francophone de Chirurgie Endocrinienne and Groupe d'étude des Tumeurs Endocrines study

OBJECTIVE

To assess recurrence according to the type of surgery for primary hyperparathyroidism (pHPT) in multiple endocrine neoplasia type 1 ( MEN1 ) patients and to identify the risk factors for recurrence after the initial surgery.

BACKGROUND

In MEN1 patients, pHPT is multiglandular, and the optimal extent of initial parathyroid resection influences the risk of recurrence.

METHODS

MEN1 patients who underwent initial surgery for pHPT between 1990 and 2019 were included. Persistence and recurrence rates after less than subtotal parathyroidectomy (LTSP) and subtotal parathyroidectomy (STP) were analyzed. Patients with total parathyroidectomy with reimplantation were excluded.

RESULTS

Five hundred seventeen patients underwent their first surgery for pHPT: 178 had LTSP (34.4%) and 339 STP (65.6%). The recurrence rate was significantly higher after LTSP (68.5%) than STP (45%) ( P < 0.001). The median time to recurrence after pHPT surgery was significantly shorter after LTSP than after STP: 4.25 (1.2-7.1) versus 7.2 (3.9-10.1) years ( P < 0.001). A mutation in exon 10 was an independent risk factor of recurrence after STP (odds ratio = 2.19; 95% CI: 1.31; 3.69; P = 0.003). The 5 and 10-year recurrent pHPT probabilities were significantly higher in patients after LTSP with a mutation in exon 10 (37% and 79% vs 30% and 61%; P = 0.016).

CONCLUSIONS

Persistence, recurrence of pHPT, and reoperation rate are significantly lower after STP than LTSP in MEN1 patients. Genotype seems to be associated with the recurrence of pHPT. A mutation in exon 10 is an independent risk factor for recurrence after STP, and LTSP may not be recommended when exon 10 is mutated.

Impact of Early Diagnostic and Therapeutic Interventions and Clinical Course in Children and Adolescents with Multiple Endocrine Neoplasia Types 1 and 2

PURPOSE

Multiple endocrine neoplasia types 1 (MEN1) and 2 (MEN2) are inherited endocrine tumor syndromes caused by mutations in the MEN1 or RET genes. This study aimed to investigate clinical outcomes and molecular characteristics among children with MEN.

METHODS

This study included eight patients from seven unrelated families. Data on clinical course, biochemical findings, and radiologic studies were collected by retrospective chart review. All diagnoses were genetically confirmed by Sanger sequencing of MEN1 in three MEN1 patients and RET in four patients with MEN2A and one patient with MEN2B.

RESULTS

Three patients with MEN1 from two families presented with hypoglycemia at a mean age of 11±2.6 years. Four patients with MEN2A were genetically diagnosed at a mean of 3.0±2.2 years of age by family screening; one of them was prenatally diagnosed by chorionic villus sampling. Three patients with MEN2A underwent prophylactic thyroidectomy from 5 to 6 years of age, whereas one patient refused surgery. The patient with MEN2B presented with a tongue neuroma and medullary thyroid carcinoma at 6 years of age. Subsequently, he underwent a subtotal colectomy because of bowel perforation and submucosal ganglioneuromatosis at 18 years of age.

CONCLUSION

This study described the relatively long clinical course of pediatric MEN with a mean follow-up duration of 7.5±3.8 years. Insulinoma was the first manifestation in children with MEN1. Early diagnosis by family screening during the asymptomatic period enabled early intervention. The patient with MEN2B exhibited the most aggressive clinical course.

A Rare Case When Acromegaly Meets Cushing Syndrome

Acromegaly is very uncommon, as is non-iatrogenic Cushing syndrome; we discuss a patient who was found to have both a pituitary adenoma causing acromegaly and a cortisol-producing adrenal adenoma causing Cushing syndrome within 1 year. She was a healthy, 44-year-old woman who presented with visual changes and was found to have bitemporal hemianopsia and a 3.3-cm pituitary mass along with central hypogonadism, central hypothyroidism, and suppressed adrenocorticotropin and discrepant cortisol. After transsphenoidal resection she had declining, but persistently elevated, insulin-like growth factor 1 (IGF-1), raising concern for persistent acromegaly. She also was experiencing several cushingoid symptoms and was found to have elevated salivary and urinary cortisol. An abdominal computed tomography scan showed a 3.1-cm adrenal adenoma, and she subsequently underwent adrenalectomy. Following adrenalectomy, her cortisol levels normalized, and her IGF-1, growth hormone, and oral glucose tolerance test showed substantial improvement consistent with previous reports linking hypercortisolism and elevated IGF-1 levels. Combinations of pituitary and adrenal disease are seen in a handful of genetic syndromes; however, her clinical presentation and genetics do not fit with known syndromes. This case describes two rare endocrine tumors in one patient and associated limitations of routine laboratory testing.

Trabecular Bone Score as a More Sensitive Tool to Evaluate Bone Involvement in MEN1-related Primary Hyperparathyroidism

CONTEXT

The skeletal involvement of multiple endocrine neoplasia type 1-related primary hyperparathyroidism (MHPT) is not exactly the same as that of sporadic primary hyperparathyroidism (SHPT). Trabecular bone score (TBS) as a texture parameter has been reported to reflect trabecular bone damage.

OBJECTIVE

This study aimed to compare the clinical characteristics, especially the skeletal involvement, between patients with MHPT and SHPT.

METHODS

The clinical characteristics were retrospectively collected in 120 patients with MHPT and compared with 360 patients with SHPT in the same period. Dual-energy X-ray absorptiometry were conducted in some patients with MHPT, in whom bone mineral density (BMD) and calculated TBS derived from lumbar spine dual-energy X-ray absorptiometry images were compared with those of patients with SHPT.

RESULTS

Although the duration of disease in the MHPT group was longer, the age at hospital visit was significantly lower than that in the SHPT group (43.5 [interquartile range, 31.5-52.0] vs 52.0 [interquartile range, 40.5-61.0], P < .001). The proportion of skeletal involvement in the MHPT group was significantly lower. However, in the subgroup of MHPT cases (n = 86) with data of BMD, there was no significant difference in skeletal involvement from SHPT cases matched for gender and age. Although the BMD and TBS in the lumbar spines of patients with MHPT were lower than those of patients with SHPT (BMD: 0.91 ± 0.18 g/cm2 vs 1.01 ± 0.17 g/cm2; TBS: 1.22 ± 0.14 vs 1.29 ± 0.11, P < .001). According to TBS, among 34 patients with MHPT with normal BMD, 15 patients had bone microstructure damage.

CONCLUSION

The cancellous bone microarchitecture was more severely damaged in patients with MHPT according to TBS, which suggested that TBS could be a sensitive supplemental index in addition to BMD to identify bone-involvement risk in patients with MHPT.

Traits of Patients With Pituitary Tumors in Multiple Endocrine Neoplasia Type 1 and Comparing Different Mutation Status

CONTEXT

Recent studies suggest that the clinical characteristics and biological behavior of pituitary tumors (PITs) in patients with multiple endocrine neoplasia type 1 (MEN1) may not be as aggressive as previously reported. Increased imaging of the pituitary as recommended by screening guidelines identifies more tumors, potentially at an earlier stage. However, it is unknown if these tumors have different clinical characteristics in different MEN1 mutations.

OBJECTIVE

To assess characteristics of patients with MEN1 with and without PITs, and compare among different MEN1 mutations.

METHODS

Data of patients with MEN1 in a tertiary referral center from 2010 to 2023 were retrospectively analyzed.

RESULTS

Forty-two patients with MEN1 were included. Twenty-four patients had PITs, 3 of which were invasive and managed with transsphenoidal surgery. One PIT enlarged during follow-up. Patients with PITs had a higher median age at MEN1 diagnosis than those without PITs. MEN1 mutations were identified in 57.1% of patients, including 5 novel mutations. In patients with PITs, those with MEN1 mutations (mutation+/PIT+ group) had more additional MEN1-associated tumors than those without (mutation-/PIT+ group). The mutation+/PIT+ group had a higher incidence of adrenal tumors and a lower median age at initial manifestation of MEN1 than the mutation-/PIT+ group. The most common neuroendocrine neoplasm was nonfunctional in the mutation+/PIT+ group and insulin-secreting in the mutation-/PIT+ group.

CONCLUSION

This is the first study comparing characteristics of patients with MEN1 with and without PITs harboring different mutations. Patients without MEN1 mutations tended to have less organ involvement and it might be reasonable for them to receive less intensive follow-up.

Coincidental Occurrence of Multiple Endocrine Neoplasia Type 1 and Breast Cancer in a Young Saudi Girl: A Case Study and Genetic Analysis

Multiple Endocrine Neoplasia Type 1 (MEN-1) is an autosomal dominant familial disorder associated with tumors in both endocrine and non-endocrine organs. It is uncommon for MEN-1 to coincide with breast cancer. We present a case of a 15-year-old Saudi girl who exhibited the classic symptoms of MEN-1 and subsequently developed breast cancer. The patient's breast cancer was diagnosed using ultrasonography and core biopsy, and she was treated with surgical interventions. Despite these treatments, her cancer progressed to a metastatic stage, and her overall health deteriorated, leading to cardiopulmonary arrest at a young age. Although the simultaneous appearance of MEN-1 and breast cancer in our patient may suggest a potential link, our comprehensive genetic analysis found no relationship between her MEN-1 mutation and the onset of breast cancer. This suggests that, in this case, the two conditions co-occurred by chance. Nonetheless, additional research is needed to explore potential associations between MEN-1 and breast cancer.

Pediatric Neuroendocrine Neoplasia of the Parathyroid Glands: Delving into Primary Hyperparathyroidism

Our objective was to overview the most recent data on primary hyperparathyroidism (PHP) in children and teenagers from a multidisciplinary perspective. Methods: narrative review based on full-length, English-language papers (from PubMed, between January 2020 and July 2023). Results: 48 papers (14 studies of ≥10 subjects/study, and 34 case reports/series of <10 patients/study). Study-sample-based analysis: except for one case-control study, all of the studies were retrospective, representing both multicenter (n = 5) and single-center (n = 7) studies, and cohort sizes varied from small (N = 10 to 19), to medium-sized (N = 23 to 36) and large (N = 63 to 83); in total, the reviewed studies covered 493 individuals with PHP. Case reports/series (n = 34, N = 41): the mean ages studied varied from 10.2 to 14 years in case reports, and the mean age was 17 years in case series. No clear female predominance was identified, unlike that observed in the adult population. Concerning the assessments, there were four major types of endpoints: imaging data collection, such as ultrasound, 99mTc Sestamibi, or dual-phase computed tomography (CT); gene testing/familial syndrome identification; preoperative findings; and exposure to surgical outcome/preoperative drugs, like cinacalcet, over a 2.2-year median (plus two case reports of denosumab used as an off-label calcium-lowering agent). Single-gland cases (representing 85% of sporadic cases and 19% of genetic PHP cases) showed 100% sensitivity for neck ultrasounds, with 98% concordance with 99mTc Sestamibi, as well as a 91% sensitivity for dual-phase CT, with 25% of the lesions being ectopic parathyroids (mostly mediastinal intra-thymic). Case reports included another 9/41 patients with ectopic parathyroid adenomas, 3/41 with parathyroid carcinomas, and 8/41 subjects with brown tumors. Genetic PHP (which has a prevalence of 5-26.9%) mostly involved MEN1, followed by CDC73, CASR, RET, and CDKN1B, as well as one case of VHL. Symptomatic PHP: 70-100% of all cases. Asymptomatic PHP: 60% of genetic PHP cases. Renal involvement: 10.5% of a cohort with genetic PHP, 71% of sporadic PHP cases; 50% (in a cohort with a mean age of 16.7), 29% (in a cohort with a mean age of 15.2); 0% (in infancy) to 50-62% (in teenagers). Bone anomalies: 83% of the children in one study and 62% of those in two other studies. Gastrointestinal issues: 40% of one cohort, but the data are heterogeneous. Cure rate through parathyroidectomy: 97-98%. Recurrent PHP: 2% of sporadic PHP cases and 38% of familial PHP cases. Hungry bone syndrome: maximum rate of 34-40%. Case reports identified another 7/41 subjects with the same post-parathyroidectomy condition; a potential connection with ectopic presentation or brown tumors is suggested, but there are limited data. Minimally invasive thoracoscopic approaches for ectopic tumors seemed safe. The current level of statistical evidence on pediatric PHP qualifies our study- and case-sample-based analysis (n = 48, N = 534) as one of the largest of its kind. Awareness of PHP is the key factor to benefit our young patients.

Pediatric head and neck manifestations associated with multiple endocrine neoplasia syndromes

INTRODUCTION

Multiple endocrine neoplasia (MEN) syndromes are a group of hereditary cancer syndromes that can predispose children to endocrine neoplasms developing within the head and neck.

OBJECTIVE

To examine the neoplastic manifestations of MEN type 1 (MEN1) and MEN type 2 (MEN2) in the pediatric head and neck.

METHODS

Single-institution, retrospective review of pediatric MEN between 2005 and 2022.

RESULTS

Fifty-three children were genetically confirmed with MEN (15 MEN1, 34 MEN2A, and 4 MEN2B), while three patients received clinical diagnoses of MEN1. The male to female ratio was essentially equal (1.15:1), and a documented family history of cancer was present in 89% (50/56). After multidisciplinary evaluation, a familial MEN diagnosis was confirmed in 91% (51/56). The mean ages of initial presentation and surgical intervention were 8.9 years (SD 5) and 9.8 years (SD 4.8), respectively. Although patients with MEN2 received surgery earlier than patients with MEN1 (8.7 vs 12.7 years), surgical patients with MEN2 in this cohort were older relative to current American Thyroid Association (ATA) guidelines primarily due to late presentation. Thyroid malignancies were identified in 36% (9/25) of thyroidectomy specimens (21 MEN2A, 4 MEN2B), with medullary thyroid carcinoma (MTC) present in five MEN2A patients and three MEN2B patients (89%), and papillary thyroid carcinoma (PTC) present in one MEN2A patient (11%). Nearly 90% (8/9) of thyroid malignancies were occult, with some occurring earlier than predicted by current guidelines (ATA-MOD and ATA-H). Central neck dissections were performed in 24% (2 MEN1, 2 MEN2A, and 4 MEN2B), with two MEN2B (50%) demonstrating cervical lymph node (LN) metastases. Additional histopathologic findings included C-cell hyperplasia in 57% (12/21) of MEN2A thyroidectomy patients. Of the eight MEN1 parathyroidectomy patients, four demonstrated parathyroid hyperplasia and four presented with parathyroid adenoma.

CONCLUSION

Nearly 60% required head and neck procedures. While MEN1 guidelines were appropriate for our cohort, we identified patients with MEN2 that developed MTC earlier than expected based on current ATA guidelines, including children in categories considered lower risk. In conjunction with a multidisciplinary approach, pediatric head and neck surgeons should be aware of the potential need for earlier surgical intervention in the pediatric MEN2 population.

A Comprehensive Review on Neuroendocrine Neoplasms: Presentation, Pathophysiology and Management

Neuroendocrine neoplasms (NENs) are a group of heterogeneous tumors with neuroendocrine differentiation that can arise from any organ. They account for 2% of all malignancies in the United States. A significant proportion of NEN patients experience endocrine imbalances consequent to increased amine or peptide hormone secretion, impacting their quality of life and prognosis. Over the last decade, pathologic categorization, diagnostic techniques and therapeutic choices for NENs-both well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs)-have appreciably evolved. Diagnosis of NEN mostly follows a suspicion from clinical features or incidental imaging findings. Hormonal or non-hormonal biomarkers (like serum serotonin, urine 5-HIAA, gastrin and VIP) and histology of a suspected NEN is, therefore, critical for both confirmation of the diagnosis and classification as an NET or NEC. Therapy for NENs has progressed recently based on a better molecular understanding, including the involvement of mTOR, VEGF and peptide receptor radionuclide therapy (PRRT), which add to the growing evidence supporting the possibility of treatment beyond complete resection. As the incidence of NENs is on the rise in the United States and several other countries, physicians are more likely to see these cases, and their better understanding may support earlier diagnosis and tailoring treatment to the patient. We have compiled clinically significant evidence for NENs, including relevant changes to clinical practice that have greatly updated our diagnostic and therapeutic approach for NEN patients.

Multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome

Retrospective study of three cases of MEN type 1 and ZES, to compare with one similar case in publication of The Spanish J of Gastroenterol: MEN-1 and ZES for pancreatic gastrinoma.

Sporadic pituitary adenoma with somatic double-hit loss of MEN1

PURPOSE

Pituitary adenomas commonly arise in patients with MEN1 syndrome, an autosomal dominant condition predisposing to neuroendocrine tumor formation, and typically diagnosed in patients with a relevant family cancer history. In these patients with existing germline loss of MEN1 on one allele, somatic loss of the second MEN1 allele leads to complete loss of the MEN1 protein, menin, and subsequent tumor formation.

METHODS

Whole exome sequencing was performed on the tumor and matching blood under an institutional board approved protocol. DNA extraction and analysis was conducted according to previously described methods.

RESULTS

We describe a 23 year-old patient with no significant past medical history or relevant family history who underwent surgical resection of a symptomatic and medically resistant prolactinoma. Whole exome sequencing of tumor and blood samples revealed somatic loss of MEN1 at both alleles, suggesting a double hit mechanism, with no underlying germline MEN1 mutation.

CONCLUSION

To our knowledge, this is the first case of pituitary adenoma to arise from somatic loss of MEN1 and in the absence of an underlying germline MEN1 mutation.

Cutaneous lesions and other non-endocrine manifestations of Multiple Endocrine Neoplasia type 1 syndrome

Background

Multiple Endocrine Neoplasia type 1 is a rare genetic syndrome mainly caused by mutations of MEN1 gene and characterized by a combination of several endocrine and non-endocrine manifestations. The objective of this study was to describe cutaneous lesions and other non-endocrine manifestations of MEN1 in a cohort of patients with familial (F) and sporadic (S) MEN1, compare the prevalence of these manifestations between the two cohorts, and investigate the correlation with MEN1 mutation status.

Methods

We collected phenotypic and genotypic data of 185 patients with F-MEN1 and S-MEN1 followed from 1997 to 2022. The associations between F-MEN1 and S-MEN1 or MEN1 mutation-positive and mutation-negative patients and non-endocrine manifestations were determined using chi-square or Fisher's exact tests or multivariate exact logistic regression analyses.

Results

The prevalence of angiofibromas was significantly higher in F-MEN1 than in S-MEN1 in both the whole (p < 0.001) and index case (p = 0.003) cohorts. The prevalence of lipomas was also significantly higher in F-MEN1 than in S-MEN1 (p = 0.009) and in MEN1 mutation-positive than in MEN1 mutation-negative (p = 0.01) index cases. In the whole cohort, the prevalence of lipomas was significantly higher in MEN1 mutation-positive compared to MEN1 mutation-negative patients (OR = 2.7, p = 0.02) and in F-MEN1 than in S-MEN1 (p = 0.03), only after adjustment for age. No significant differences were observed for the other non-endocrine manifestations between the two cohorts. Hibernoma and collagenoma were each present in one patient (0.5%) and meningioma and neuroblastoma in 2.7% and 0.5%, respectively. Gastric leiomyoma was present in 1.1% of the patients and uterine leiomyoma in 14% of women. Thyroid cancer, breast cancer, lung cancer, basal cell carcinoma, melanoma, and colorectal cancer were present in 4.9%, 2.7%, 1.6%, 1.6%, 2.2%, and 0.5% of the whole series, respectively.

Conclusions

We found a significantly higher prevalence of angiofibromas and lipomas in F-MEN1 compared with S-MEN1 and in MEN1 mutation-positive compared to MEN1 mutation-negative patients. In patients with one major endocrine manifestation of MEN1 , the presence of cutaneous lesions might suggest the diagnosis of MEN1 and a possible indication for genetic screening.

Role of Exendin-4 Functional Imaging in Diagnosis of Insulinoma: A Systematic Review

BACKGROUND

Insulinomas are the most common neuroendocrine neoplasms of the pancreas. Diagnosis is made through patient clinical presentation with hypoglycemia symptoms and imaging, such as EUS, CT, MRI, and functional imaging. Exendin-4 PET/CT (and SPECT/CT) is a new prominent radiotracer developed to image insulinomas. The aim of the study is to evaluate whether exendin-4 imaging is a useful tool in imaging for insulinoma patients when other imaging methods do not reach them.

METHODS

MEDLINE research conducted on PubMed, Scopus, and Web of Science gathered a total of 501 papers. Studies that evaluated exendin-4 SPECT and PET in insulinoma patients were screened and assessed through QUADAS-2 for risk of bias and applicability concerns' assessment. Sensitivity, specificity, and accuracy were reported when available.

RESULTS

A total of 13 studies were deemed eligible for a QUADAS 2 review. Studies included ranged from 2009 to 2022. The most-used tracer was ⁶⁸Ga-DOTA-exendin-4 in PET and ¹¹¹In-DTPA-exendin-4 in SPECT. Exendin-4 labeled with ⁹⁹mTc was also reported. The QUADAS-2 risk of bias assessment was overall low, with some unclear reports in the reference and index domains. Only two domains were at high risk of bias because of an explicated non-blind imaging review. Applicability concerns for bias were low in all domains. Reported sensitivities ranged from 95% to 100% and specificities from 20% to 100%.

CONCLUSIONS

exendin-4 imaging is a sensitive functional imaging tracer in both SPECT and PET applications, especially in suspicion of benign insulinomas located where endoscopic ultrasound cannot reach, being more sensitive than morfostructural imaging.

Multiple Endocrine Neoplasia Type 1 Syndrome Pancreatic Neuroendocrine Tumor Genotype/Phenotype: Is There Any Advance on Predicting or Preventing?

Multiple endocrine neoplasia type 1 syndrome (MEN1) is a disease caused by mutations in the MEN1 tumor suppressor gene leading to hyperparathyroidism, pituitary adenomas, and entero-pancreatic neuroendocrine tumors. Pancreatic neuroendocrine tumors (PNETs) are a major cause of mortality in patients with MEN1. Identification of consistent genotype-phenotype correlations has remained elusive, but MEN1 mutations in exons 2, 9, and 10 may be associated with metastatic PNETs; patients with these mutations may benefit from more intensive surveillance and aggressive treatment. In addition, epigenetic differences between MEN1-associated PNETs and sporadic PNETs are beginning to emerge, but further investigation is required to establish clear phenotypic associations.

Pathogenic variants among females with breast cancer and a non-breast cancer reveal opportunities for cancer interception

PURPOSE

Herein, we report the frequency and distribution of germline pathogenic variants (PVs) among females with breast cancer (BC) and at least one other non-BC who underwent multi-gene panel testing (MGPT). Among females with PVs diagnosed first with BC or ovarian cancer (OC), we sought to enumerate the frequency of subsequent PV-associated cancers.

METHODS

Females with BC and cancer of ≥ 1 other site (multiple primary cancers, MPC) who underwent MGPT through Ambry Genetics from March 2012 to December 2016 were included if they had testing of at least 21 genes of interest (ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, NBN, NF1, PALB2, PMS2, PTEN, RAD51C, RAD51D, STK11, and TP53). Phenotypic data were abstracted from test requisition forms and clinical notes.

RESULTS

Of 6,617 evaluable patients, most were White (70.8%) and median age at first cancer, second cancer, and MGPT was 49 (interquartile range [IQR]: 18), 59 (IQR: 16), and 63 (IQR: 16) years, respectively. PVs were found among 14.1% (932/6617) of the overall cohort and in 16.4% (440/2687) of females who were diagnosed first with BC. Among those, 55.2% (243/440) had an actionable PV associated with a subsequent cancer diagnosis including 150 OCs. Of the 2443 females with breast and ovarian cancer, few (n = 97, 9.5%) were diagnosed first with OC, limiting our analysis.

CONCLUSIONS

Females with MPC, including BC, have a high frequency of germline PVs (14.1%). These data delineate the opportunities for intercepting subsequent cancers associated with genetic risk among females diagnosed first with BC.

Hereditary cancer syndromes

Hereditary cancer syndromes (HCSs) are arguably the most frequent category of Mendelian genetic diseases, as at least 2% of presumably healthy subjects carry highly-penetrant tumor-predisposing pathogenic variants (PVs). Hereditary breast-ovarian cancer and Lynch syndrome make the highest contribution to cancer morbidity; in addition, there are several dozen less frequent types of familial tumors. The development of the majority albeit not all hereditary malignancies involves two-hit mechanism, i.e. the somatic inactivation of the remaining copy of the affected gene. Earlier studies on cancer families suggested nearly fatal penetrance for the majority of HCS genes; however, population-based investigations and especially large-scale next-generation sequencing data sets demonstrate that the presence of some highly-penetrant PVs is often compatible with healthy status. Hereditary cancer research initially focused mainly on cancer detection and prevention. Recent studies identified multiple HCS-specific drug vulnerabilities, which translated into the development of highly efficient therapeutic options.

Familial parathyroid tumours-comparison of clinical profiles between syndromes

INTRODUCTION

Primary hyperparathyroidism (PHPT) caused by parathyroid tumours is mostly sporadic, with a genetic cause identified in 5-10% of cases. Familial parathyroid tumours can be included in complex syndromes, such as multiple endocrine neoplasia (MEN) type 1, 2A and 4 or hyperparathyroidism-jaw tumour syndrome (HPT-JT).

OBJECTIVE

Characterisation of the familial parathyroid tumours followed-up at our centre and comparison of the different clinicopathological manifestations between the syndromes.

METHODS

Retrospective analysis of 48 patients with familial parathyroid tumours harbouring RET (n = 11), CDC73 (n = 20) and MEN1 (n = 17) germline mutations was performed.

RESULTS

Cases of PHPT in MEN2A syndrome presented with lower serum PTH (sPTH) and serum calcium (sCa) levels at diagnosis (sPTH = 108.0 (IQR 53.3) pg/mL, sCa = 10.6 ± 1.1 mg/dL) than MEN1 (sPTH = 196.9 (IQR 210.5) pg/mL, sCa = 11.7 ± 1.2 mg/dL) (p = 0.01, p = 0.03, respectively) or HPT-JT cases (sPTH = 383.5 (IQR 775.8) pg/mL, sCa = 12.9 ± 1.8 mg/dL) (p = 0.01; p < 0.001, respectively). There was a statistical difference in sCa levels between MEN1 and HPT-JT (p = 0.02), but not between sPTH (p = 0.07). The predominant first manifestation of the syndrome in MEN1 was gastroenteropancreatic neuroendocrine tumour (GEP-NET) in 47.1% of the cases, in MEN2A was medullary thyroid cancer (90.9%) and in HPT-JT was PHPT in 85% patients. In MEN1 syndrome, the number of affected parathyroid glands was significantly higher than in MEN2A (p < 0.001) and HPT-JT (p = 0.01).

CONCLUSION

The first manifestation of the syndrome in MEN1 cases was GEP-NET and not PHPT. Although presenting at similar ages, patients with MEN2A exhibit less severe biochemical and clinical PHPT at diagnosis than the other familial syndromes.

Approach of Multiple Endocrine Neoplasia Type 1 (MEN1) Syndrome-Related Skin Tumors

Non-endocrine findings in patients with MEN1 (multiple endocrine neoplasia) syndrome also include skin lesions, especially tumor-type lesions. This is a narrative review of the English-language medical literature including original studies concerning MEN1 and dermatological issues (apart from dermatologic features of each endocrine tumor/neuroendocrine neoplasia), identified through a PubMed-based search (based on clinical relevance, with no timeline restriction or concern regarding the level of statistical significance). We identified 27 original studies involving clinical presentation of patients with MEN1 and cutaneous tumors; eight other original studies that also included the genetic background; and four additional original studies were included. The largest cohorts were from studies in Italy (N = 145 individuals), Spain (N = 90), the United States (N = 48 and N = 32), and Japan (N = 28). The age of patients varied from 18 to 76 years, with the majority of individuals in their forties. The most common cutaneous tumors are angiofibromas (AF), collagenomas (CG), and lipomas (L). Other lesions are atypical nevi, basocellular carcinoma, squamous cell carcinoma, acrochordons, papillomatosis confluens et reticularis, gingival papules, and cutaneous T-cell lymphoma of the eyelid. Non-tumor aspects are confetti-like hypopigmentation, café-au-lait macules, and gingival papules. MEN1 gene, respective menin involvement has also been found in melanomas, but the association with MEN1 remains debatable. Typically, cutaneous tumors (AF, CG, and L) are benign and are surgically treated only for cosmetic reasons. Some of them are reported as first presentation. Even though skin lesions are not pathognomonic, recognizing them plays an important role in early identification of MEN1 patients. Whether a subgroup of MEN1 subjects is prone to developing these types of cutaneous lesions and how they influence MEN1 evolution is still an open issue.

Genetics of monogenic disorders of calcium and bone metabolism

Disorders of calcium homeostasis are the most frequent metabolic bone and mineral disease encountered by endocrinologists. These disorders usually manifest as primary hyperparathyroidism (PHPT) or hypoparathyroidism (HP), which have a monogenic aetiology in 5%-10% of cases, and may occur as an isolated endocrinopathy, or as part of a complex syndrome. The recognition and diagnosis of these disorders is important to facilitate the most appropriate management of the patient, with regard to both the calcium-related phenotype and any associated clinical features, and also to allow the identification of other family members who may be at risk of disease. Genetic testing forms an important tool in the investigation of PHPT and HP patients and is usually reserved for those deemed to be an increased risk of a monogenic disorder. However, identifying those suitable for testing requires a thorough clinical evaluation of the patient, as well as an understanding of the diversity of relevant phenotypes and their genetic basis. This review aims to provide an overview of the genetic basis of monogenic metabolic bone and mineral disorders, primarily focusing on those associated with abnormal calcium homeostasis, and aims to provide a practical guide to the implementation of genetic testing in the clinic.

Long-Term Outcomes for Patients with Multiple Endocrine Neoplasia Type 1 and Duodenopancreatic Neuroendocrine Neoplasms

BACKGROUND

Liver metastasis from duodenopancreatic neuroendocrine neoplasms (DP-NENs) is a major cause of mortality in multiple endocrine neoplasia type 1 (MEN1) patients, yet much of their natural history is unknown.

METHODS

This longitudinal, retrospective cohort study analyzed all MEN1 patients with imageable functional (F) and nonfunctional (NF) DP-NENs (1990-2021) for liver metastasis-free survival (LMFS) and overall survival (OS).

RESULTS

Of 138 patients, 85 (61.6%) had imageable DP-NENs (28 F, 57 NF), and the mean largest tumor size was 1.8 ± 1.4 cm. Multifocality was present in 32 patients (37.7%). Surgery was performed for 49 patients (57.7%). During an 11-year median follow-up period (IQR, 6-17 years), 23 (27.1%) of the patients had liver metastasis, and 19 (22.4%) patients died. Death was attributed to liver metastasis in 60% of cases. The patients with F-DP-NENs versus NF-DP-NENs more often had liver metastasis (46.4% vs. 15.8%; p = 0.002) but had similar 10-year LMFS (80.9 vs. 87.0%; p = 0.44) and OS (82.7 vs. 94.3%; p = 0.69). The patients with NF-DP-NENs had surgery when their tumors were larger (p < 0.001). Tumor size was not associated with liver metastasis (p = 0.89). The average growth rate was 0.04 cm/year (SE, 0.02 cm/year; p = 0.01) during active surveillance for NF-DP-NENs (n = 38). Liver metastasis developed in four patients with tumors smaller than 2 cm. The risk of liver metastasis was independent of surgery (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.21-2.93; p = 0.72) and death (HR, 0.51; 95% CI, 0.08-3.06; p = 0.46).

CONCLUSIONS

Although the observed outcomes in this study were better than historical data, small NF-DP-NENs still developed liver metastasis and liver metastasis remains a major cause of death. These results suggest that size as a sole criterion for surgery may be insufficient to predict tumor behavior.

Thymoma (World Health Organization Type AB) in multiple endocrine neoplasia type 1: a case report

Thymic neoplasms are rarely seen among patients with multiple endocrine neoplasia type 1 (MEN1) and appear to be especially rare when pathological examination reveals a World Health Organization Type AB thymoma. In the case presented here, we report a 39-year-old woman with Type AB thymoma in MEN1. A 7.8-cm-sized mediastinal mass was diagnosed as a thymic neoplasm by computed tomography. In addition, pituitary tumor and hypercalcemia from parathyroid hyperplasia were found. Therefore, the patient was clinically diagnosed with MEN1 syndrome and underwent surgical resection of thymic tumor. At the 1-year follow-up, the patient appeared to be healthy without any sign of reoccurrence. Despite its rare occurrence, our case provides us with a new awareness that thymoma may coexist with MEN1.

Less Than Subtotal Parathyroidectomy for Multiple Endocrine Neoplasia Type 1 Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1)-associated primary hyperparathyroidism (pHPT) is classically associated with an asymmetric and asynchronous parathyroid involvement. Subtotal parathyroidectomy (STP), which is currently the recommended surgical treatment, carries a high risk of permanent hypoparathyroidism. The results of less than subtotal parathyroidectomy (LSTP) are conflicting, and its place in this setting is still a matter of debate. The aim of this study was to identify the place of LSTP in the surgical management of patients with MEN-associated pHPT.

METHODS

A systematic literature review was conducted in accordance with PRISMA and MOOSE guidelines, for studies comparing STP and LSTP for MEN1-associated pHPT. The results of the two techniques, regarding permanent hypoparathyroidism, persistent hyperparathyroidism and recurrent hyperparathyroidism were computed using pairwise random-effect meta-analysis.

RESULTS

Twenty-five studies comparing STP and LSTP qualified for inclusion in the quantitative synthesis. In total, 947 patients with MEN1-associated pHPT were allocated to STP (n = 569) or LSTP (n = 378). LSTP reduces the risk of permanent hypoparathyroidism [odds ratio (OR) 0.29, confidence interval (CI) 95% 0.17-0.49)], but exposes to higher rates of persistent hyperparathyroidism [OR 4.60, 95% CI 2.66-7.97]. Rates of recurrent hyperparathyroidism were not significantly different between the two groups [OR 1.26, CI 95% 0.83-1.91].

CONCLUSIONS

LSTP should not be abandoned and should be considered as a suitable surgical option for selected patients with MEN1-associated pHPT. The increased risk of persistent hyperparathyroidism could improve with the emergence of more efficient preoperative localization imaging techniques and a more adequate patients selection.

Analysis of 55 patients with multiple endocrine neoplasia type 1-associated insulinoma from a single center in China

Objective

To investigate the clinical characteristics of patients with multiple endocrine neoplasia type 1 (MEN1)-related insulinoma and their relationship with specific biochemical changes and to summarize the features of treatment options for the Chinese population with this disease and the impact on long-term prognosis.

Methods

“MEN1” and “insulinoma” were used when searching the Peking Union Medical College Hospital (PUMCH) medical record retrieval system to obtain clinical information about patients. We identified patients diagnosed with MEN1-associated insulinoma based on endocrinological, radiological, and pathological examinations, and subsequently analyzed their clinical data.

Results

A total of 55 patients with MEN1-associated insulinoma were included, including 29 (52.7%) men and 26 (47.3%) women. The parathyroid gland was the most commonly affected (78.2%), followed by the pituitary gland (69.1%) and adrenal gland (16.4%). Insulinoma was the first manifestation of MEN1 in at least 23.6% (13/55) of patients. Nineteen (34.5%) patients presented with initial symptoms of hypoglycemia before the age of 22 years. Among the 24 Patients with high serum calcium (Ca) had significantly lower serum insulin levels than those with normal serum Ca levels (p < 0.001) during hypoglycemic episodes. However, serum C-peptide level at 0.5 h and serum insulin level at 1 h was higher in patients with hypercalcemia than in patients with normal serum Ca levels in the oral glucose tolerance test (OGTT), although the differences were not statistically significant. Multifocal pancreatic neuroendocrine tumors (pNETs) were present in 38 (69.1%) patients; most of them (55.6%, 20/36) underwent multiple enucleations, and 45% (9/20) had a postoperative recurrence. Five patients (10%) who underwent distal pancreatectomy developed pancreatic insufficiency after an average of seven years. patients who underwent genetic testing, 23 (95.8%) were positive for MEN1 mutation, with mutations most commonly found in exons 2 (21.7%) and 3 (13%).

Conclusions

In our study, the rates of postoperative recurrence and long-term complications in patients with MEN1 with multifocal pNETs were significantly different from those in other international centers and might be related to the choice of surgical method. In addition, elevated serum Ca levels in patients with primary hyperparathyroidism may affect insulin secretion.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02370-1.

Value of Somatostatin Receptor PET/CT in Patients With MEN1 at Various Stages of Their Disease

CONTEXT

Despite the growing evidence of the clinical value of somatostatin receptor (SSTR) positron emission tomography (PET) in the evaluation of neuroendocrine tumors (NETs), its role remains to be clarified at different time points in the journey of patients with multiple endocrine neoplasia type 1 (MEN1). The rarity of the disease is however a significant impediment to prospective clinical trials.

OBJECTIVE

The goals of the study were to assess the indications and value of SSTR PET/computed tomography (CT) in patients with MEN1.

METHODS

We retrospectively included patients from 7 French expert centers for whom data on SSTR PET/CT and morphological imaging performed at the same period were available. Detection rates of PET study were analyzed.

RESULTS

One hundred and 8 patients were included. SSTR PET/CT was performed at screening (n = 33), staging (n = 34), restaging (n = 37), and for peptide receptor targeted radiotherapy selection (n = 4). PET detected positive pancreatic lesions in 91% of cases at screening, with results comparable with magnetic resonance imaging but superior to CT (P = .049). Metastases (mostly lymph node [LN]) were present at the screening phase in 28% of cases, possibly due to the suboptimal value of screening morphological imaging in the assessment of nodal metastases and/or a long delay between imaging studies. SSTR PET/CT was considered superior or complementary to the reference standard in the assessment of LN or distant metastases in the vast majority of cases and regardless of the clinical scenario.

CONCLUSION

This study shows the potential added value of SSTR PET in the assessment of MEN1-associated NETs and provides great impetus toward its implementation in the evaluation of patients with MEN1.

Multiple Endocrine Neoplasia Type 1 with Functional Parathyroid Cysts

A 51-year-old woman was admitted because of hypercalcemia. Neck ultrasonography and computed tomography revealed the presence of parathyroid cysts on both sides. After primary hyperparathyroidism was diagnosed by technetium-99m-methoxyisobutylisonitrile scintigraphy, the patient was successfully treated with total parathyroidectomy and autotransplantation. She also had a non-functioning pancreatic neuroendocrine tumor, prolactinoma, and adrenal tumors with subclinical Cushing's syndrome. Given these clinical features and her family history, multiple endocrine neoplasia type 1 (MEN1) was suspected, and germline DNA sequencing revealed a missense mutation (c.1013T>C, [corrected] p.Leu338Pro) in exon 7 of MEN1. This case demonstrates the phenotypic and genetic diversity of MEN1.

The Research Landscape of Multiple Endocrine Neoplasia Type 1 (2000–2021): A Bibliometric Analysis

Introduction

This study aimed to investigate the landscape of Multiple Endocrine Neoplasia Type 1 research during the last 22 years using machine learning and text analysis.

Method

In December 2021, all publications indexed under the MeSH term “Multiple Endocrine Neoplasia Type 1” were obtained from PubMed. The whole set of search results was downloaded in XML format, and metadata such as title, abstract, keywords, mesh words, and year of publication were extracted from the original XML files for bibliometric evaluation. The Latent Dirichlet allocation (LDA) topic modeling method was used to analyze specific themes.

Results

This study eventually contained 1,407 publications. Among them, there are 768 (54.58%) case reports and reviews. Text analysis based on MeSH words revealed that the most often studied clinical areas include therapy efficacy, prognosis, and genetic diagnosis. The majority of basic study is focused on genetic alterations. The LDA topic model further identifies three topic clusters include basic research, treatment cluster, and diagnosis cluster. In the basic research cluster, many studies are focused on the expression of Menin. The primary focus of the therapy cluster is pancreatic resections and parathyroidectomy. In the diagnose cluster, the main focus is on Genetic Diagnosis and screening strategies for Hereditary Cancer Syndrome.

Conclusion

The current state of research on MEN1 is far from adequate. Research on rare diseases MEN1 necessitates implementing a broad research program involving multiple centers to advance MEN1 research together.

Noninvasive Prenatal Diagnosis of a Paternally Inherited MEN1 Pathogenic Splicing Variant

CONTEXT

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disease caused by mutations in the tumor suppressor gene MEN1. The uncertainty of pathogenicity of MEN1 variants complexifies the selection of the patients likely to benefit from specific care.

OBJECTIVE

MEN1-mutated patients should be offered tailored tumor screening and genetic counseling. We present a patient with hyperparathyroidism for whom genetic analysis identified a variant of uncertain significance in the MEN1 gene (NM_130799.2): c.654G > T p.(Arg218=). Additional functional genetic tests were performed to classify the variant as pathogenic and allowed prenatal testing.

DESIGN

Targeted next generation sequencing identified a synonymous variant in the MEN1 gene in a 26-year-old male with symptomatic primary hyperparathyroidism. In silico and in vitro genetic tests were performed to assess variant pathogenicity.

RESULTS

Genetic testing of the proband's unaffected parents showed the variant occurred de novo. Transcript study showed a splicing defect leading to an in-frame deletion. The classification of the MEN1 variant as pathogenic confirmed the diagnosis of MEN1 and recommended an adapted medical care and follow-up. Pathogenic classification also allowed to propose a genetic counseling to the proband and his wife. Noninvasive prenatal diagnosis was performed with a personalized medicine-based protocol by detection of the paternally inherited variant in maternal plasmatic cell free DNA, using digital PCR.

CONCLUSION

We showed that functional genetic analysis can help to assess the pathogenicity of a MEN1 variant with crucial consequences for medical care and genetic counseling decisions.

The Importance of Periodical Screening for Primary Hyperparathyroidism in a Pituitary Tumor Cohort in Searching Patients with MEN1 and its Genetic Profile

OBJECTIVE

Multiple endocrine neoplasia type 1 (MEN1) is a rare genetic syndrome characterized by parathyroid, anterior pituitary, and/or duodenopancreatic neuroendocrine tumors. Studies have indicated that investigating primary hyperparathyroidism (pHPT) with subsequent genetic screening may be an essential tool for the early diagnosis of MEN1 in patients with pituitary tumors (PTs). This study aimed to investigate the presence of pHPT in patients with PTs and, subsequently, to screen for genetic mutations and related tumors in those with MEN1 Syndrome.

METHODS

This study included 255 patients with PTs who were assessed for the presence of MEN1 from serum calcium and parathyroid hormone measurements. Mutation screening of the MEN1, CDKN1B, and AIP genes was performed in the index cases showing the MEN1 phenotype.

RESULTS

Five PT-evaluated patients presented a clinical condition compatible with MEN1. These patients had a younger age of onset and a more severe clinical condition. Genetic analysis identified a frameshift mutation in the MEN1 gene in one of the cases with the MEN1 phenotype, but point mutations in CDKN1B and AIP were not detected in any of these patients.

CONCLUSION

Our findings show that periodic screening for pHPT in patients with PTs may be useful to detect MEN1 syndrome; thus, it is recommended in those patients genetic analysis of MEN1 gene and an additional search of related tumors. By contrast, our results suggest that CDKN1B and AIP mutations do not seem to play a relevant role in the pathogenesis of MEN1.

Overview of the 2022 WHO Classification of Familial Endocrine Tumor Syndromes

This review of the familial tumor syndromes involving the endocrine organs is focused on discussing the main updates on the upcoming fifth edition of the WHO Classification of Endocrine and Neuroendocrine Tumors. This review emphasizes updates on histopathological and molecular genetics aspects of the most important syndromes involving the endocrine organs. We describe the newly defined Familial Cancer Syndromes as MAFA-related, MEN4, and MEN5 as well as the newly reported pathological findings in DICER1 syndrome. We also describe the updates done at the new WHO on the syndromic and non-syndromic familial thyroid diseases. We emphasize the problem of diagnostic criteria, mention the new genes that are possibly involved in this group, and at the same time, touching upon the role of some immunohistochemical studies that could support the diagnosis of some of these conditions. As pathologists play an important role in identifying tumors within a familial cancer syndrome, we highlight the most important clues for raising the suspicious of a syndrome. Finally, we highlight the challenges in defining these entities as well as determining their clinical outcome in comparison with sporadic tumors. Instead of the usual subject review, we present the highlights of the updates on familial cancer syndromes by answering select questions relevant to practicing pathologists.

[Severe bone complications of primary hyperparathyroidism in a young patient with the rare verified mutation of MEN1]

Multiple endocrine neoplasia type 1 syndrome (MEN1) is a rare inherited disorder that can include combinations of more than 20 endocrine and non-endocrine tumors. Unfortunately, none of the described MEN1 mutations has been associated with a peculiar clinical phenotype, even within members of the same family, thus a genotype-to-phenotype correlation does not exist. MEN1 syndrome is the most common cause of hereditary primary hyperparathyroidism (PHPT), the disease penetrance of which exceeds 50% by the age of 20 and reaches 95% by the age of 40. At the same time, PHPT with hyperplasia or adenomas of the parathyroid glands (PTG) is the most distinctive manifestation of the MEN1 syndrome. One of the main symptoms of PHPT, both in sporadic and hereditary forms of the disease, is bone damage. At the time of diagnosis in PHPT/MEN1, the bone mineral density is generally lower in comparison with the sporadic form of PHPT. This may be due to excessive secretion of parathyroid hormone during the period of peak bone mass, concomitant components of the syndrome, extended surgical treatment, and the direct effect of a mutation in the menin gene on bone remodeling. This clinical case describes a young patient with severe bone complications of PHPT and uncertain rare MEN1 mutation. PHPT was diagnosed five years later from the first onset of bone complications and repeated orthopedic operations. There was the «hungry bones» syndrome after successful surgery of PHPT, which was managed with vitamin D and calcium carbonate supplementation and there is a positive dynamic in increased bone mineral density in the main skeleton after 6 months.