No evidence of adverse fertility and pregnancy outcomes in patients with unrecognized and untreated multiple endocrine neoplasia type 1.

OBJECTIVE: Literature concerning the impact of multiple endocrine neoplasia type 1 (MEN 1) on fertility is limited to case reports despite the early onset of endocrinopathies, such as primary hyperparathyroidism and prolactinoma, that may impact fertility. This study describes the impact of unrecognized and untreated MEN 1 on fertility and pregnancy outcomes in a multigenerational cohort of the Tasman 1 MEN 1 kindred. METHODS: All MEN 1 positive (MEN 1+ , n = 63) and MEN 1 negative (MEN 1- , n = 75) descendants born between 1825 and 1951 of a common founder. Review of birth, death, marriage and medical records provided data on date of birth and death, gender, MEN 1 status and the number of pregnancies and children per parent. RESULTS: Compared to MEN 1- parents, MEN 1+ parents had more children (RR 1.30, 1.02-1.66) and live births (RR 1.31, 1.02-1.67) with no excess of stillbirths (RR 1.24, 0.24-6.36). Compared to the era-matched Tasmanian fertility rate, MEN 1+ parents had more children (4.87 ± 4.11 vs 3.40 ± 0.61, P = 0.048), whereas MEN 1- parents had similar numbers of children (3.67 ± 3.27 vs 3.36 ± 0.62, P = 0.55). MEN 1+ parents had a similar number of MEN 1+ and MEN 1- offspring (2.1 ± 1.9 vs 2.5 ± 2.3, P = 0.31). Indirectly assessed miscarriage rate was similar between MEN 1+ and MEN 1- mothers (P = 0.77). Clinically overt pituitary disease reduced MEN 1+ kindred member likelihood of parenthood (33% vs 97%). CONCLUSIONS: There was no adverse impact of MEN 1 on patient fertility overall; however, MEN 1-related pathology may have impaired the reproductive potential of a subset of individuals with pituitary disease.

[TYPE 1 MULTIPLE ENDOCRINE NEOPLASIA SYNDROME AND FAMILIAL ISOLATED HYPERPARATHYROIDISM].

Type 1 multiple endocrine neoplasia syndrome (MEN-1) is a rare autosomal dominant disorder caused by mutation in the MEN-1 gene and manifest as a combination of tumours of parathyroid glands, endocrine pancreas, and adenohypophysis. Familial isolated hyperparathyroidism (FIHP) is another rare autosomal dominant disorder characterized by the development ofparathyroid tumours as the sole endocrinopathy within a single family. The notion of FIHP encompasses different hereditary forms of primary hyperparathyroidism, such as a variant of MEN-1 syndrome. This paper is a brief literature review of the problems related to primary hyperparathyroidism, MEN-1, and FIHP. Also, It describes a family presenting with genetically confirmed MEN-1 syndrome, manifest as primary hyperparathyroidism.

Parasitic myomas after laparoscopic-assisted myomectomy in multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant hereditary disorder that develops multiple tumors arising from various endocrine organs, including the parathyroid gland, endocrine pancreas and pituitary gland. Although mesenchymal tumors can be an integral part of the syndrome, parasitic peritoneal myomas have never been described in an MEN1 patient. Seven years after laparoscopic-assisted myomectomy, parasitic peritoneal myomas were diagnosed in a 31-year-old woman with situs inversus totalis and previous history of parathyroid adenoma. Subsequently, MEN1 was clinically diagnosed by identification of endocrine pancreatic, adrenal and pituitary tumors. Genetic analysis revealed a heterozygous germline mutation in the splice donor sequence of intron 6 of the MEN1 gene. Although rare, parasitic peritoneal myomas could potentially be associated with MEN1 syndrome.

Cinacalcet efficacy in patients with moderately severe primary hyperparathyroidism according to the European Medicine Agency prescription labeling.

BACKGROUND: Patients with primary hyperparathyroidism (PHPT) with contraindications to parathyroidectomy (PTx) or persistent PHPT have few non surgical options. AIM: The aim of the study was to investigate the efficacy of cinacalcet in reducing serum calcium in patients with PHPT, for whom PTx would be indicated according to serum calcium levels, but in whom PTx is not clinically appropriate or is contraindicated [European Medicines Agency (EMA) prescription labeling]. SUBJECTS AND METHODS: The study (open-label prospective, conducted in a single tertiary center) included 12 sporadic and 2 multiple endocrine neoplasia type 1 PHPT patients with serum calcium greater than 11.2 mg/dl. Cinacalcet was administered in increasing doses until normal serum calcium was reached or side effects preventing a further increase occurred. Serum calcium, PTH, phosphate, 25OHD, markers of bone turnover, 24h-urinary calcium and areal bone mineral density (BMD) were measured. Safety biochemical indices and adverse events were monitored. RESULTS: The maintenance cinacalcet dose [median 30 mg twice daily (range 30 daily-60 mg twice daily)] was maintained constant during follow-up (median 12 months). Mean±SE baseline serum calcium was 12.2±0.3 mg/dl. Serum calcium decreased by at least 1 mg/dl in all patients and normalized in 10. Serum calcium at the last observation was 9.9±0.2 mg/dl (p<0.0001 vs baseline). PTH decreased by 17.1% compared to baseline (p=0.13), and never reached a normal value. BMD was unchanged. Adverse events occurred in 6 patients (43%) and required treatment withdrawal in 2. CONCLUSIONS: Cinacalcet reduced and often normalized serum calcium in PHPT patients who met the EMA labeling.

Delay in the diagnosis of multiple endocrine neoplasia type 1: typical symptoms are frequently overlooked.

The morbidity and mortality of individuals with multiple endocrine neoplasia type 1 (MEN1) can be reduced by early diagnosis of MEN1 and related endocrine tumors. To find factors contributing to early diagnosis, we collected clinical information on MEN1 patients through a MEN study group, "MEN Consortium of Japan" and analyzed the time of initial symptom-dependent detection of parathyroid tumors, gastro-entero-pancreatic neuroendocrine tumors (GEPNETs) and pituitary tumors, and that of tumor detection-dependent MEN1 diagnosis in 560 patients. Main tumors were identified up to 7.0 years after symptoms appeared and there was no difference in age at the diagnosis of GEPNETs alone between probands and family members. In patients with typical symptoms (peptic ulcers, urolithiasis, fasting hypoglycemia, bone fracture/loss and amenorrhea), the mean interval between symptom manifestation and tumor detection was extended up to 9.6 years. In particular, 21.7% (5/23) of patients with amenorrhea were diagnosed with pituitary tumors in under one year. In patients with peptic ulcers (from parathyroid tumors or GEPNETs) and urolithiasis (from parathyroid tumors), the interval was positively correlated with age at tumor detection. The interval between tumor detection and MEN1 diagnosis was also prolonged to approximately four years in patients with fasting hypoglycemia (from GEPNETs) and amenorrhea. A substantial delay in the diagnosis of symptom-related tumors and subsequent MEN1 and inadequate screening of GEPNETs in family members were indicated. A greater understanding of MEN1 may assist medical practitioners to make earlier diagnoses, to share patients' medical information and to give family members sufficient disease information.

Menin regulates the function of hematopoietic stem cells and lymphoid progenitors.

Men1 is a tumor suppressor gene mutated in endocrine neoplasms. Besides its endocrine role, the Men1 gene product menin interacts with the mixed lineage leukemia (MLL) protein, a histone H3 lysine 4 methyltransferase. Although menin and MLL fusion proteins cooperate to activate Homeobox (Hox) gene expression during transformation, little is known about the normal hematopoietic functions of menin. Here, we studied hematopoiesis after Men1 ablation. Menin loss modestly impaired blood neutrophil, lymphocyte, and platelet counts. Without hematopoietic stress, multilineage and myelo-erythroid bone marrow progenitor numbers were preserved, while B lymphoid progenitors were decreased. In contrast, competitive transplantation revealed a marked functional defect of long-term hematopoietic stem cells (HSC) in the absence of menin, despite normal initial homing of progenitors to the bone marrow. HoxA9 gene expression was only modestly decreased in menin-deficient HSCs. These observations reveal a novel and essential role for menin in HSC homeostasis that was most apparent during situations of hematopoietic recovery, suggesting that menin regulates molecular pathways that are essential during the adaptive HSC response to stress.

Clinical and prognostic implications of the genetic diagnosis of hereditary NET syndromes in asymptomatic patients.

Neuroendocrine tumors (NETs) can be sporadic or they can arise in complex hereditary syndromes. Patients with hereditary NETs can be identified before the development of tumors by performing genetic screenings. The aim of the study was to evaluate the clinical and prognostic impact of a preclinical genetic screening in subjects with hereditary NET syndromes. 46 subjects referred for hereditary NET syndrome [22 MEN1, 12 MEN2, 12 Familial Paragangliomatosis (FPGL)] were enrolled and divided in 2 groups (group A, 20 subjects with clinical appearance of NET before the genetic diagnosis; group B, 26 subjects with genetic diagnosis of hereditary NET syndromes before the clinical appearance of NETs). The main outcome measures were severity of disease, prognosis, and survival. The rate of surgery for MEN1-, MEN2-, FPGL4-related tumors was 90% in group A and 35% in group B (p<0.01). Both symptoms related to tumors and symptoms related to therapies were significantly less frequent in group B than in group A (p<0.05). Tumor stage was locally advanced or metastatic in 50% of group A and in no one of group B (p<0.01). The mortality rate was 25% in group A and 0% in group B (p<0.05). An early genetic screening for hereditary NET syndromes results in an improvement in clinical presentation and morbidity. A potential impact of the genetic screening on the mortality rate of these subjects is suggested and needs to be investigated in further and more appropriate studies.

Initiating Pancreatic Neuroendocrine Tumor (pNET) Screening in Young MEN1 Patients: Results From the DutchMEN Study Group.

CONTEXT: Nonfunctioning pancreatic neuroendocrine tumors (NF-pNETs) are highly prevalent and constitute an important cause of mortality in patients with multiple endocrine neoplasia type 1 (MEN1). Still, the optimal age to initiate screening for pNETs is under debate. OBJECTIVE: The aim of this work is to assess the age of occurrence of clinically relevant NF-pNETs in young MEN1 patients. METHODS: Pancreatic imaging data of MEN1 patients were retrieved from the DutchMEN Study Group database. Interval-censored survival methods were used to describe age-related penetrance, compare survival curves, and develop a parametric model for estimating the risk of having clinically relevant NF-pNET at various ages. The primary objective was to assess age at occurrence of clinically relevant NF-pNET (size ≥ 20 mm or rapid growth); secondary objectives were the age at occurrence of NF-pNET of any size and pNET-associated metastasized disease. RESULTS: Five of 350 patients developed clinically relevant NF-pNETs before age 18 years, 2 of whom subsequently developed lymph node metastases. No differences in clinically relevant NF-pNET-free survival were found for sex, time frame, and type of MEN1 diagnosis or genotype. The estimated ages (median, 95% CI) at a 1%, 2.5%, and 5% risk of having developed a clinically relevant tumor are 9.5 (6.5-12.7), 13.5 (10.2-16.9), and 17.8 years (14.3-21.4), respectively. CONCLUSION: Analyses from this population-based cohort indicate that start of surveillance for NF-pNETs with pancreatic imaging at age 13 to 14 years is justified. The psychological and medical burden of screening at a young age should be considered.

Diagnostic challenges due to phenocopies: lessons from Multiple Endocrine Neoplasia type1 (MEN1).

Phenocopies may confound the clinical diagnoses of hereditary disorders. We report phenocopies in Multiple Endocrine Neoplasia type 1 (MEN1), an autosomal dominant disorder, characterised by the combined occurrence of parathyroid, pituitary and pancreatic tumours. We studied 261 affected individuals from 74 families referred with a clinical diagnosis of MEN1 and sought inconsistencies between the mutational and clinical data. We identified four patients from unrelated families with phenocopies. Patients 1 and 2 from families with MEN1, developed prolactinomas as the sole endocrinopathy but they did not harbour the germline MEN1 mutation present in their affected relatives. Patient 3, had acromegaly and recurrent hypercalcaemia following parathyroidectomy, whilst patient 4 had parathyroid tumours and a microprolactinoma. Patients 3 and 4 and their relatives did not have MEN1 mutations, but instead had familial hypocalciuric hypercalcaemia (FHH) due to a calcium-sensing receptor mutation (p.Arg680Cys), and the hyperparathyroidism-jaw tumour (HPT-JT) syndrome due to a hyperparathyroidism type 2 deletional-frameshift mutation (c.1239delA), respectively. Phenocopies may mimic MEN1 either by occurrence of a single sporadic endocrine tumour in a patient with familial MEN1, or occurrence of two endocrine abnormalities associated with different aetiologies. Phenocopies arose in >5% of MEN1 families, and awareness of them is important in the clinical management of MEN1 and other hereditary disorders.

Islet cell tumours.

Pancreatic endocrine tumours can cause hormonal symptoms by over-secretion of hormones. They are less aggressive than exocrine pancreatic cancer, but carry a variable prognosis. The tumours are either sporadic or hereditary, as part of the multiple endocrine neoplasia type 1 syndrome. Despite the rarity of these tumours, they evoke significant interest in the research community and important advances have been made over the past years. This chapter provides an overview of the tumours and recent advances in the field. Hereditary forms of pancreatic endocrine tumours are caused by mutations in the MEN1 gene. Menin, the protein encoded by this gene, has been shown to interact with numerous transcription factors and proteins involved in cell-cycle control, shedding some light on the importance of the protein. Several genes have been shown to be up- or down-regulated, suggesting candidates to be further evaluated for a role in tumourigenesis. Several advances have been made in prognostication; a tumour-node-metastasis system has been evaluated and seems to have prognostic value, and several new molecular prognostic markers are under evaluation. It is hoped that the tumour-node-metastasis system and other prognostic markers will be adopted in clinical routine and improve prognostication and treatment choices. Surgery is still the only cure, but several new palliative drugs and interventions are in use or under investigation. Radiofrequency ablation is increasingly used for liver metastases, and a number of new chemotherapy drugs are being tested. Despite improvements in treatment, no clear improvement in survival has been demonstrated.

Parental Multiple Endocrine Neoplasia Type 1 (MEN 1) Is Associated with Increased Offspring Childhood Mortality.

CONTEXT: Information regarding the impact of parental multiple endocrine neoplasia type 1 (MEN 1) on neonatal outcomes is limited to case reports. OBJECTIVE: To determine the impact of parental MEN 1 on neonatal outcomes. METHODS: Retrospective cohort analysis of the Tasman 1 MEN 1 kindred stratified by whether birth occurred before ("historical cohort") or after ("contemporary cohort") prospective screening commenced. The historical cohort included kindred members born between 1825 and 1984 (n = 341 children with a MEN 1 positive (MEN 1+) parent and n = 314 children with MEN 1 negative (MEN 1-) parents). The contemporary cohort included neonates (n = 52) of MEN 1+ women (n = 21) managed at a tertiary referral hospital between 1985 and 2018. RESULTS: Historical cohort: compared with MEN 1- parents, children of MEN 1+ parents were more likely to die postpartum (HR 4.6, P = .046 at 6 months of age). Excess mortality at 15 years of age was observed for children of MEN 1+ mothers (HR 8.50, P = .002) and fathers (HR 3.82, P = .03). Contemporary cohort: neonates of MEN 1+ mothers were more likely to have low birth weight (28.9% vs 6.7%, P = .01), be admitted to a higher care nursery (40.4% vs 17%, P = .02), and require a longer median postnatal stay (5 vs 4 days, P = .009) than the Australian average. Isolated antenatal hypercalcemia did not significantly alter neonatal outcomes. CONCLUSION: Children with a MEN 1+ parent are disproportionately vulnerable postpartum. Neonates of MEN 1+ mothers remain vulnerable despite contemporary care. The excess risk was not fully explained by maternal MEN 1 or antenatal hypercalcemia.

Bone Metabolism and Vitamin D Implication in Gastroenteropancreatic Neuroendocrine Tumors.

Patients affected by gastroenteropancreatic-neuroendocrine tumors (GEP-NETs) have an increased risk of developing osteopenia and osteoporosis, as several factors impact on bone metabolism in these patients. In fact, besides the direct effect of bone metastasis, bone health can be affected by hormone hypersecretion (including serotonin, cortisol, and parathyroid hormone-related protein), specific microRNAs, nutritional status (which in turn could be affected by medical and surgical treatments), and vitamin D deficiency. In patients with multiple endocrine neoplasia type 1 (MEN1), a hereditary syndrome associated with NET occurrence, bone damage may carry other consequences. Osteoporosis may negatively impact on the quality of life of these patients and can increment the cost of medical care since these patients usually live with their disease for a long time. However, recommendations suggesting screening to assess bone health in GEP-NET patients are missing. The aim of this review is to critically analyze evidence on the mechanisms that could have a potential impact on bone health in patients affected by GEP-NET, focusing on vitamin D and its role in GEP-NET, as well as on factors associated with MEN1 that could have an impact on bone homeostasis.

Reverse referral: from pathology to endocrinology.

Establishing a diagnosis of multiple endocrine neoplasia type 1 (MEN1) especially in children, adolescents, and young adults can be challenging because of phenotypic heterogeneity even among family members. We report an adolescent girl diagnosed to have MEN1 following presentation with multiple collagenomas. Histological evaluation of her cutaneous lesions revealed >70 collagenomas. Hormonal evaluation included calcium, phosphate, and parathormone measurements. Exons 2-10 of the MEN1 gene and flanking intron-exon borders were sequenced and revealed a novel nonsense mutation, Y222X. Following the identification of the cutaneous lesions as collagenomas by the pathologist, the patient was referred for an endocrine evaluation which revealed asymptomatic primary hyperparathyroidism. The patient elected to have surgery at which time she was found to have parathyroid hyperplasia. This case emphasizes the usefulness of cutaneous findings for the diagnosis and management of MEN1.

Functional studies of menin through genetic manipulation of the Men1 homolog in mice.

To investigate the physiological role of menin, the protein product of the MEN1 gene, several groups have utilized gene targeting strategies to delete one or both copies of the mouse homolog Men1. Mice that are homozygous null for Men1 die during embryogenesis. Heterozygous Men1 mice are viable and develop many of the same types of tumors as humans with MEN1. In addition to conventional knockouts of Men1, tissue-specific elimination of menin using cre-lox has been achieved in pancreatic beta cells, anterior pituitary, parathyroid, liver, neural crest and bone marrow, with varying results that are dependent on cell context. In this chapter, we compare the phenotypes of the different conventional Men1 knockouts, detail the similarities and differences between Men1 pathogenesis in mice and humans and highlight results from recent crossbreeding studies between Men1 mutants and mice with null mutations in genes within the retinoblastoma pathway, including p18(Inc4c), p27(Kip1) and Rb. In addition, we discuss not only how the Men1 mutants have shed light on the role of menin in endocrine tumor suppression, but also how Men1 mutant mice have helped uncover previously unrecognized roles for menin in development, leukemogenesis and gestational diabetes.

MEN1 clinical background.

Multiple endocrine neoplasia Type 1 (MEN1) is a rare hereditary tumor syndrome predisposing to tumor development in several endocrine organs. Its major manifestations include hyperparathyroidism, tumors of endocrine pancreas and pituitary. Beside these three, several other endocrine (adrenocortical, foregut carcinoid) and nonendocrine (lipoma, angiofibroma, collagenoma, ependymoma, meningioma) tumors have been described to be associated with this syndrome. Both familial and sporadic forms of the disease are known. The diagnosis of MEN1 can be established if two of the three major manifestations are found in the same patient, whereas the diagnosis of familial MEN1 requires one MEN1 patient and a first degree relative with at least one MEN1 manifestation. MEN1 is transmitted as an autosomal dominant trait with high penetrance, approaching 95-100% by the age of 60. Both benign (parathyroid, anterior pituitary) and malignant (gastrinoma, glucagonoma) lesions may develop in MEN1 patients. Regular surveillance of MEN1 gene mutation carriers is necessary to reveal disease manifestations. Several diagnostic modalities can be used to screen for and to examine MEN1-related tumors. The therapy of MEN1-associated tumors requires specific approach in some cases, as multiple tumors and recurrence is frequently observed.

Menin: the protein behind the MEN1 syndrome.

The cloning of the MEN1 gene in 1997 led to the characterization of menin, the protein behind the multiple endocrine neoplasia Type 1 syndrome. Menin, a novel nuclear protein with no homology to other gene products, is expressed ubiquitously. MEN1 missense mutations are dispersed along the coding region of the gene but are more common in the most conserved regions. Likewise, domains of protein interaction often correspond to the more conserved segments of menin. These protein interactions are generally facilitated by multiple domains or encompass a large portion of menin. The exception to this rule is a small stretch of amino acids mediating the interaction of menin with the mSin3A corepressor and histone deacetylase complexes. The C-terminal region of menin harbors several nuclear localization signals that play redundant functions in the localization of menin to the nuclear compartment. The nuclear localization signals are also important for the interaction of menin with the nuclear matrix. Menin is the target of several kinases and a candidate substrate of the ATM/ATR kinases, implying a role for this tumor suppressor in the DNA damage response. Menin is highly conserved from Drosophila to human but is absent in the nematode and in yeast.

The role of menin in parathyroid tumorigenesis.

Primary hyperparathyroidism is a common disorder that involves the pathological enlargement of one or more parathyroid glands resulting in excessive production of parathyroid hormone (PTH). The exact pathogenesis of this disease remains to be fully understood. In recent years interest has focussed on the interaction between menin protein and the transforming growth factor (TGF)-beta/Smad signalling pathway. In vitro experimentation has demonstrated that the presence of menin is required for TGF-beta to effectively inhibit parathyroid cell proliferation and PTH production. This observation correlates with the almost universal occurrence of parathyroid tumors accompanying the inactivation of menin in multiple endocrine neoplasia Type 1 (MEN1) syndrome and the high rate of somatic menin gene mutations seen in sporadic parathyroid adenomas. This chapter aims to review the role of menin in primary hyperparathyroidism and parathyroid hormone-regulation, including the influences of MEN1 gene mutations on parathyroid cell proliferation, differentiation and tumorigenesis.

Parathyroid hormone-dependent hypercalcemia.

The past fifteen years have resulted in great progress in our understanding of the pathogenesis and pathophysiology of hypercalcemic disorders occurring either sporadically or in a familial setting. This paper briefly reviews the clinically most important new knowledge on sporadic and hereditary forms of parathyroid hormone-dependent hypercalcemic disorders, with special emphasis on familial syndromes such as multiple endocrine neoplasia type 1 and type 2A, hyperparathyroidism-jaw tumor syndrome, familial isolated hyperparathyroidism, familial hypocalciuric hypercalcemia and neonatal severe primary hyperparathyroidism. In addition, the authors briefly present the most important clinical characteristics of 141 patients with parathyroid hormone-dependent hypercalcemia, including index patients of 18 families with hereditary disorders, diagnosed in a Hungarian endocrine center between 1997 and 2007.

Menin, histone h3 methyltransferases, and regulation of cell proliferation: current knowledge and perspective.

Menin is a tumor suppressor encoded by the MEN1 gene that is mutated in patients with an inherited syndrome, multiple endocrine neoplasia type 1 (MEN1). Loss of menin has potent impact on proliferation of endocrine and non-endocrine cells. However, until recently little has been known as to how menin regulates cell proliferation. Rapid research progress in the past several years suggests that menin represses proliferation of endocrine cells yet promotes proliferation in certain types of leukemia cells via interacting with various transcriptional regulators. Menin interacts with histone H3 methyltransferases such as MLL (mixed lineage leukemia) protein. Increasing evidence has linked the biological function of menin to epigenetic histone modifications, control of the pattern of gene expression, and regulation of cell proliferation in a cell type-specific manner. In light of these recent findings, an emerging model suggests that menin is a crucial regulator of histone modifiers by acting as a scaffold protein to coordinate gene transcription and cell proliferation in a cell context-dependent manner. This recent progress unravels the coordinating role of menin in epigenetics and regulation of cell cycle, providing novel insights into understanding regulation of beta cell functions and diabetes, as well as the development and therapy of endocrine tumors and leukemia.

Complex endocrinopathies in MEN-1: diagnostic dilemmas in endocrine oncology.

Endocrine oncology is a complex area that must determine the site of a neoplastic process and the hormonal dysregulation that ensues. Patients with endocrine tumors often have delayed diagnosis because of the nonspecific and often subtle signs and symptoms. In patients with multiple endocrine neoplasia syndromes, diagnosis and clinicopathologic correlations can be even more challenging. We report a patient with multiple endocrine neoplasia type 1 (MEN-1) and a highly complex clinical story associated with multiple atypical lesions including two pituitary adenomas, a gonadotroph macroadenoma and a corticotroph microadenoma with Crooke's hyaline change and ectopic production of corticotropin-releasing hormone (CRH) from a thymic endocrine carcinoma. These lesions resulted in a highly complex clinical story, difficult diagnoses and questions about management. This case illustrates a number of clinically relevant challenges, including the diagnosis of pituitary adenomas in MEN-1, the difficulty in diagnosing Cushing's disease, and the large differential of pituitary pathologies in this disorder, double pituitary adenomas and other decoy lesions in Cushing's disease, the pathophysiology of Crooke's hyaline change in the pituitary, and the various causes of Cushing's syndrome associated with MEN-1.