Clinical Features of Multiple Endocrine Neoplasia Type 4: Novel Pathogenic Variant and Review of Published Cases

Multiple endocrine neoplasia 2A with RET mutation p.Cys611Tyr: A case report

RATIONALE

Multiple endocrine neoplasia 2A (MEN2A) is a rare autosomal-dominant genetic syndrome, frequently misdiagnosed or neglected clinically, resulting in delayed therapy to patients.

PATIENT CONCERNS

A 47-year-old Chinese male patient underwent laparoscopic right adrenal tumorectomy, and postoperative pathology confirmed the tumor as pheochromocytoma (PHEO). He was readmitted to the department of endocrinology and metabolism due to constant increase in carcinoembryonic antigen (CEA) at 5 months after the operation.

DIAGNOSIS

The patient was confirmed with medullary thyroid carcinoma (MTC), multiple neck lymph node metastasis, and pituitary microadenoma. The p.Cys611Tyr (c.1832G>A, C611Y) mutation was detected. Therefore, he was diagnosed with MEN2A.

INTERVENTIONS

He underwent total thyroidectomy. The gene-sequencing analysis of his family was conducted, and the C611Y mutation was detected in his daughter.

OUTCOMES

The level of carcinoembryonic antigen decreased significantly after thyroidectomy in this patient. Long-term follow-up management was conducted. Elevated serum calcitonin and bilateral thyroid nodules were found in his 13-year-old daughter. Thus, MEN2A was highly suspected and she was suggested to undergo total thyroidectomy.

CONCLUSION

Patients with MEN2A should be screened regularly and managed by a multidisciplinary team.

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

Objective

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

Background

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

Methods

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

Conclusions

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

Clinical aspects of multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome characterized by the co-occurrence of primary hyperparathyroidism, duodenopancreatic neuroendocrine tumours (NETs) and/or pituitary adenomas. MEN1 can predispose patients to other endocrine and non-endocrine tumours, such as cutaneous tumours, central nervous system tumours and breast cancer. Endocrine tumours in patients with MEN1 differ from sporadic tumours in that they have a younger age at onset, present as multiple tumours in the same organ and have a different clinical course. Therefore, patients with overt MEN1 and those who carry a MEN1 mutation should be offered tailored biochemical and imaging screening to detect tumours and evaluate their progression over time. Fortunately, over the past 10 years, knowledge about the clinical phenotype of these tumours has markedly progressed, thanks to the implementation of national registries, particularly in France and the Netherlands. This Review provides an update on the clinical management of MEN1-related tumours. Epidemiology, the clinical picture, diagnostic work-up and the main lines of treatment for MEN1-related tumours are summarized. Controversial therapeutic aspects and issues that still need to be addressed are also discussed. Moreover, special attention is given to MEN1 manifestations in children and adolescents.

Genetics of Acromegaly and Gigantism

Growth hormone (GH)-secreting pituitary tumours represent the most genetically determined pituitary tumour type. This is true both for germline and somatic mutations. Germline mutations occur in several known genes (AIP, PRKAR1A, GPR101, GNAS, MEN1, CDKN1B, SDHx, MAX) as well as familial cases with currently unknown genes, while somatic mutations in GNAS are present in up to 40% of tumours. If the disease starts before the fusion of the epiphysis, then accelerated growth and increased final height, or gigantism, can develop, where a genetic background can be identified in half of the cases. Hereditary GH-secreting pituitary adenoma (PA) can manifest as isolated tumours, familial isolated pituitary adenoma (FIPA) including cases with AIP mutations or GPR101 duplications (X-linked acrogigantism, XLAG) or can be a part of systemic diseases like multiple endocrine neoplasia type 1 or type 4, McCune-Albright syndrome, Carney complex or phaeochromocytoma/paraganglioma-pituitary adenoma association. Family history and a search for associated syndromic manifestations can help to draw attention to genetic causes; many of these are now tested as part of gene panels. Identifying genetic mutations allows appropriate screening of associated comorbidities as well as finding affected family members before the clinical manifestation of the disease. This review focuses on germline and somatic mutations predisposing to acromegaly and gigantism.

Multiple Endocrine Neoplasia Type 1: Latest Insights

Multiple endocrine neoplasia type 1 (MEN1), a rare tumor syndrome that is inherited in an autosomal dominant pattern, is continuing to raise great interest for endocrinology, gastroenterology, surgery, radiology, genetics, and molecular biology specialists. There have been 2 major clinical practice guidance papers published in the past 2 decades, with the most recent published 8 years ago. Since then, several new insights on the basic biology and clinical features of MEN1 have appeared in the literature, and those data are discussed in this review. The genetic and molecular interactions of the MEN1-encoded protein menin with transcription factors and chromatin-modifying proteins in cell signaling pathways mediated by transforming growth factor β/bone morphogenetic protein, a few nuclear receptors, Wnt/β-catenin, and Hedgehog, and preclinical studies in mouse models have facilitated the understanding of the pathogenesis of MEN1-associated tumors and potential pharmacological interventions. The advancements in genetic diagnosis have offered a chance to recognize MEN1-related conditions in germline MEN1 mutation-negative patients. There is rapidly accumulating knowledge about clinical presentation in children, adolescents, and pregnancy that is translatable into the management of these very fragile patients. The discoveries about the genetic and molecular signatures of sporadic neuroendocrine tumors support the development of clinical trials with novel targeted therapies, along with advancements in diagnostic tools and surgical approaches. Finally, quality of life studies in patients affected by MEN1 and related conditions represent an effort necessary to develop a pharmacoeconomic interpretation of the problem. Because advances are being made both broadly and in focused areas, this timely review presents and discusses those studies collectively.

Molecular Pathology of Well-Differentiated Pulmonary and Thymic Neuroendocrine Tumors: What Do Pathologists Need to Know?

Thoracic (pulmonary and thymic) neuroendocrine tumors are well-differentiated epithelial neuroendocrine neoplasms that are classified into typical and atypical carcinoid tumors based on mitotic index cut offs and presence or absence of necrosis. This classification scheme is of great prognostic value but designed for surgical specimens, only. Deep molecular characterization of thoracic neuroendocrine tumors highlighted their difference with neuroendocrine carcinomas. Neuroendocrine tumors of the lung are characterized by a low mutational burden, and a high prevalence of mutations in chromatin remodeling and histone modification-related genes, whereas mutations in genes frequently altered in neuroendocrine carcinomas are rare. Molecular profiling divided thymic neuroendocrine tumors into three clusters with distinct clinical outcomes and characterized by a different average of copy number instability. Moreover, integrated histopathological, molecular and clinical evidence supports the existence of a grey zone category between neuroendocrine tumors (carcinoid tumors) and neuroendocrine carcinomas. Indeed, cases with well differentiated morphology but mitotic/Ki-67 indexes close to neuroendocrine carcinomas have been increasingly recognized. These are characterized by specific molecular profiles and have an aggressive clinical behavior. Finally, thoracic neuroendocrine tumors may arise in the background of genetic susceptibility, being MEN1 syndrome the well-defined familial form. However, pathologists should be aware of rarer germline variants that are associated with the concurrence of neuroendocrine tumors of the lung or their precursors (such as DIPNECH) with other neoplasms, including but not limited to breast carcinomas. Therefore, genetic counseling for all young patients with thoracic neuroendocrine neoplasia and/or any patient with pathological evidence of neuroendocrine cell hyperplasia-to-neoplasia progression sequence or multifocal disease should be considered.

Co-occurrence of multiple endocrine neoplasia type 4 and spinal neurofibromatosis: a case report

Multiple Endocrine Neoplasia (MEN) type 4 is a rare genetic condition that results from variants of the CDKN1B gene and predisposes individuals to develop endocrine tumors. Spinal neurofibromatosis (SNF) is an uncommon subtype of neurofibromatosis type 1 (NF1) characterized by bilateral neurofibromas of all spinal roots. Here we report a case of the co-occurrence of these syndromes, which has not yet been described in the literature. A male in his 60s presented with Gleason 5 + 4 localized prostate adenocarcinoma treated with radical prostatectomy. Two years later, he developed liver and bone metastasis consistent with trans-differentiation into small cell carcinoma. He developed hypercalcemia due to primary hyperparathyroidism from a parathyroid adenoma treated surgically. His family history was significant for a first-degree relative with a clinical diagnosis of NF1 and several second-degree relatives with multiple café-au-lait macules. Spine MRI showed multiple bilateral neurofibromas. Germline genetic testing showed a pathogenic variant in the CDKN1B gene, a variant in the NF1 gene, and a normal MEN1 gene. In this rare case of MEN4 and SNF, the patient was asymptomatic for much of his life. In addition to parathyroid adenoma and spinal neurofibromas, he had prostate adenocarcinoma with trans-differentiation into metastatic small cell cancer. Whether this diagnosis was coincidental or related to an emerging phenotype remains to be elucidated.

Clinical Features, Management, and Molecular Characteristics of Familial Small Bowel Neuroendocrine Tumors

Small bowel neuroendocrine tumors are rare tumors with an increasing incidence over the last several decades. Early detection remains challenging because patients commonly develop symptoms late in the disease course, often after the tumors have metastasized. Although these tumors were thought to arise from sporadic genetic mutations, large epidemiological studies strongly support genetic predisposition and increased risk of disease in affected families. Recent studies of familial small bowel neuroendocrine tumors have identified several novel genetic mutations. Screening for familial small bowel neuroendocrine tumors can lead to earlier diagnosis and improved patient outcomes. This review aims to summarize the current knowledge of molecular changes seen in familial small bowel neuroendocrine tumors, identify clinical features specific to familial disease, and provide strategies for screening and treatment.

Familial Hyperparathyroidism

Regulation of the serum calcium level in humans is achieved by the endocrine action of parathyroid glands working in concert with vitamin D and a set of critical target cells and tissues including osteoblasts, osteoclasts, the renal tubules, and the small intestine. The parathyroid glands, small highly vascularized endocrine organs located behind the thyroid gland, secrete parathyroid hormone (PTH) into the systemic circulation as is needed to keep the serum free calcium concentration within a tight physiologic range. Primary hyperparathyroidism (HPT), a disorder of mineral metabolism usually associated with abnormally elevated serum calcium, results from the uncontrolled release of PTH from one or several abnormal parathyroid glands. Although in the vast majority of cases HPT is a sporadic disease, it can also present as a manifestation of a familial syndrome. Many benign and malignant sporadic parathyroid neoplasms are caused by loss-of-function mutations in tumor suppressor genes that were initially identified by the study of genomic DNA from patients who developed HPT as a manifestation of an inherited syndrome. Somatic and inherited mutations in certain proto-oncogenes can also result in the development of parathyroid tumors. The clinical and genetic investigation of familial HPT in kindreds found to lack germline variants in the already known HPT-predisposition genes represents a promising future direction for the discovery of novel genes relevant to parathyroid tumor development.

Hereditary Parathyroid Disease: Sometimes Pathologists Do Not Know What They Are Missing

Parathyroid gland excision specimens are common and sometimes underestimated cases that many surgical pathologists encounter regularly. In the vast majority of cases, these will be spot diagnoses of sporadic primary parathyroid adenomas or, perhaps, hyperplasias commonly in the setting of renal failure. However, a small but significant number of parathyroid gland excisions may be due to heritable disease. In most cases, hereditary disease is suspected by the referring clinicians. Nevertheless, a subset of these are undetected which is significant, particularly in the setting of the multiple endocrine neoplasia (MEN), and the hyperparathyroidism jaw tumour (HPT-JT) syndromes. There have been recent advances in recognition of the morphological and immunohistochemical characteristics of these tumours and hyperplasias. While hereditary kindreds are over-represented at specialist referral centres, with awareness of the characteristic clinical and morphological features, the general surgical pathologist is frequently able to suggest the possibility of hereditary parathyroid disease. We therefore provide a succinct guide for pathologists to increase the recognition of hereditary parathyroid disease.

Clinical and Molecular Update on Genetic Causes of Pituitary Adenomas

Pituitary adenomas are benign tumors with variable functional characteristics that can have a significant impact on patients. The majority arise sporadically, but an inherited genetic susceptibility is increasingly being recognized. Recent advances in genetics have widened the scope of our understanding of pituitary tumorigenesis. The clinical and genetic characteristics of pituitary adenomas that develop in the setting of germline-mosaic and somatic GNAS mutations (McCune-Albright syndrome and sporadic acromegaly), germline MEN1 mutations (multiple endocrine neoplasia type 1), and germline PRKAR1A mutations (Carney complex) have been well described. Non-syndromic familial cases of isolated pituitary tumors can occur as familial isolated pituitary adenomas (FIPA); mutations/deletions of the AIP gene have been found in a minority of these. Genetic alterations in GPR101 have been identified recently as causing X-linked acro-gigantism (X-LAG) leading to very early-onset pediatric gigantism. Associations of pituitary adenomas with other tumors have been described in syndromes like multiple endocrine neoplasia type 4, pheochromocytoma-paraganglioma with pituitary adenoma association (3PAs) syndrome and some of their genetic causes have been elucidated. The genetic etiologies of a significant proportions of sporadic corticotropinomas have recently been identified with the discovery of USP8 and USP48 mutations. The elucidation of genetic and molecular pathophysiology in pituitary adenomas is a key factor for better patient management and effective follow-up.

Clinical and Molecular Genetics of Primary Hyperparathyroidism

Calcium homeostasis is maintained by the actions of the parathyroid glands, which release parathyroid hormone into the systemic circulation as necessary to maintain the serum calcium concentration within a tight physiologic range. Excessive secretion of parathyroid hormone from one or more neoplastic parathyroid glands, however, causes the metabolic disease primary hyperparathyroidism (HPT) typically associated with hypercalcemia. Although the majority of cases of HPT are sporadic, it can present in the context of a familial syndrome. Mutations in the tumor suppressor genes discovered by the study of such families are now recognized to be pathogenic for many sporadic parathyroid tumors. Inherited and somatic mutations of proto-oncogenes causing parathyroid neoplasia are also known. Future investigation of somatic changes in parathyroid tumor DNA and the study of kindreds with HPT yet lacking germline mutation in the set of genes known to predispose to HPT represent two avenues likely to unmask additional novel genes relevant to parathyroid neoplasia.

Germline CDKN1B Loss-of-Function Variants Cause Pediatric Cushing's Disease With or Without an MEN4 Phenotype

CONTEXT

Germline loss-of-function CDKN1B gene variants cause the autosomal dominant syndrome of multiple endocrine neoplasia type 4 (MEN4). Even though pituitary neuroendocrine tumors are a well-known component of the syndrome, only 2 cases of Cushing's disease (CD) have so far been described in this setting.

AIM

To screen a large cohort of CD patients for CDKN1B gene defects and to determine their functional effects.

PATIENTS

We screened 211 CD patients (94.3% pediatric) by germline whole-exome sequencing (WES) only (n = 157), germline and tumor WES (n = 27), Sanger sequencing (n = 6), and/or germline copy number variant (CNV) analysis (n = 194). Sixty cases were previously unpublished. Variant segregation was investigated in the patients' families, and putative pathogenic variants were functionally characterized.

RESULTS

Five variants of interest were found in 1 patient each: 1 truncating (p.Q107Rfs*12) and 4 nontruncating variants, including 3 missense changes affecting the CDKN1B protein scatter domain (p.I119T, p.E126Q, and p.D136G) and one 5' untranslated region (UTR) deletion (c.-29_-26delAGAG). No CNVs were found. All cases presented early (10.5 ± 1.3 years) and apparently sporadically. Aside from colon adenocarcinoma in 1 carrier, no additional neoplasms were detected in the probands or their families. In vitro assays demonstrated protein instability and disruption of the scatter domain of CDKN1B for all variants tested.

CONCLUSIONS

Five patients with CD and germline CDKN1B variants of uncertain significance (n = 2) or pathogenic/likely pathogenic (n = 3) were identified, accounting for 2.6% of the patients screened. Our finding that germline CDKN1B loss-of-function may present as apparently sporadic, isolated pediatric CD has important implications for clinical screening and genetic counselling.

Inherited syndromes involving pancreatic neuroendocrine tumors

Inherited syndromes are important to recognize in the setting of a pancreatic neuroendocrine tumor (PNET) as there are significant implications for the patient's medical management and opportunity for early detection of subsequent manifestations. Although most PNETs are sporadic, approximately 10% are due to an inherited syndrome, which include multiple endocrine neoplasia type 1 (MEN1), multiple endocrine neoplasia type 4 (MEN4), von Hippel-Lindau disease (VHL), neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC). The general hallmarks of a hereditary endocrine neoplasia predisposition syndrome include any one of the following: multiple primary tumors (in the same or different organs), rare tumors (prevalence of less than 1 in 1,000 people in the general population), earlier age of diagnosis (usually under the age of 40), characteristic pattern of disease in the individual or family (phenotype and inheritance pattern). These syndromes are monogenic (due to a single gene disorder), highly penetrant (with all carriers of the disease exhibiting at least part of the phenotype) and can display variable expressivity (where affected individuals may have different presentations and features of the disease). A thoughtful approach to management is required, even if the presenting symptom is resolved, as these syndromes often involve multi-organ disease with a lifelong risk for tumor development. Additionally, the natural history of tumors in the setting of a hereditary condition may be different than would be expected in a sporadic form of the disease. For example, in some circumstances the risk of metastatic disease is lower, and therefor longer observation is the preferred approach over early surgical intervention. The unique aspects to management, challenges in hereditary disease recognition and accurate diagnosis, and rarity of these syndromes are all reasons to support referral to high-volume centers with the experience and knowledge to treat patients with hereditary endocrine neoplasia syndromes.

Potential markers of disease behavior in acromegaly and gigantism

Introduction: Acromegaly and gigantism entail increased morbidity and mortality if left untreated, due to the systemic effects of chronic GH and IGF-1 excess. Guidelines for the diagnosis and treatment of patients with GH excess are well established; however, the presentation, clinical behavior and response to treatment greatly vary among patients. Numerous markers of disease behavior are routinely used in medical practice, but additional biomarkers have been recently identified as a result of basic and clinical research studies.Areas covered: This review focuses on genetic, molecular and genomic features of patients with GH excess that have recently been linked to disease progression and response to treatment. A PubMed search was conducted to identify markers of disease behavior in acromegaly and gigantism. Markers already considered as part of routine studies in clinical care guidelines were excluded. Literature search was expanded for each marker identified. Novel markers not included or only partially covered in previously published reviews on the subject were prioritized.Expert opinion: Recognizing the most relevant markers of disease behavior may help the medical team tailoring the strategies for approaching each case of acromegaly and gigantism. This customized plan should make the evaluation, treatment and follow up process more efficient, greatly improving the patients' outcomes.

Hereditary Syndromes in Neuroendocrine Tumors

OPINION STATEMENT

Oncologists should be able to discern the salient clinical features of the most common germline mutations that give rise to neuroendocrine tumors. Astute recognition of an index patient affected by a hereditary syndrome can lead to a "tip-of-the-iceberg" phenomenon whereby their entire kindred can then be proactively monitored and managed potentially with substantial reduction of morbidity and mortality. Through careful history-taking, as well as thoughtful assimilation of findings from the physical exam, biochemical laboratories, scans, and pathology reports, the clinician can spot phenotypic clues that distinguish these familial patterns from sporadic cases of tumorigenesis.

[Inherited tumor syndromes of gastroenteropancreatic and thoracic neuroendocrine neoplasms]

About 5% of gastroenteropancreatic and thoracic neuroendocrine neoplasms (NENs) arise in the context of an inherited tumour syndrome. The two most frequent syndromes are: multiple endocrine neoplasia type 1 (MEN1), associated with a large spectrum of endocrine and non endocrine tumours, including duodenopancreatic, thymic and bronchial NENs, and the von Hippel-Lindau syndrome VHL, associated with pancreatic NENs. Two inherited syndromes have a low incidence of NENs: neurofibromatosis type 1 (NF1), associated with duodenal somatostatinomas, and tuberous sclerosis (TSC), associated with pancreatic NENs. Two rare syndromes have a high incidence of NENs: multiple endocrine neoplasia type 4 (MEN4), with a tumour spectrum similar to that of MEN1, and glucagon cell hyperplasia neoplasia (GCHN), involving only the pancreas. It is likely that other syndromes remain to be characterized, especially in familial small-intestinal NENs. The diagnosis is usually raised because of the suggestive clinical setting: young age at diagnosis, multiple tumours in multiple organs, familial history. Except in VHL and NF1, tumours themselves do not show specific pathological features; they usually are well differentiated and of low histological grade; their prognosis is good, except for MEN1-associated thymic NENs. The most suggestive pathological feature is their combination with various endocrine and/or non endocrine lesions in the adjacent tissue. Pathological examination is important, for a correct diagnosis and for an accurate management of the patients and their families, who must be referred to expert centers.

Molecular Signatures and Their Clinical Utility in Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) are classified based on their histologic differentiation and proliferative indices, which have been used extensively to determine prognosis. Advances in next-generation sequencing and other high-throughput techniques have allowed researchers to objectively explore tumor specimens and learn about the genetic alterations associated with malignant transformation in PNETs. As a result, targeted, pathway-specific therapies have been emerging for the treatment of unresectable and metastatic disease. As we continue to trial various pharmaceutical products, evidence from studies using multi-omics approaches indicates that clinical aggressiveness stratifies along other genotypic and phenotypic demarcations, as well. In this review, we explore the clinically relevant and potentially targetable molecular signatures of PNETs, their associated trials, and the overall differences in reported prognoses and responses to existing therapies.

The Genetics of Pituitary Adenomas

The genetic landscape of pituitary adenomas (PAs) is diverse and many of the identified cases remain of unclear pathogenetic mechanism. Germline genetic defects account for a small percentage of all patients and may present in the context of relevant family history. Defects in AIP (mutated in Familial Isolated Pituitary Adenoma syndrome or FIPA), MEN1 (coding for menin, mutated in Multiple Endocrine Neoplasia type 1 or MEN 1), PRKAR1A (mutated in Carney complex), GPR101 (involved in X-Linked Acrogigantism or X-LAG), and SDHx (mutated in the so called "3 P association" of PAs with pheochromocytomas and paragangliomas or 3PAs) account for the most common familial syndromes associated with PAs. Tumor genetic defects in USP8, GNAS, USP48 and BRAF are some of the commonly encountered tissue-specific changes and may explain a larger percentage of the developed tumors. Somatic (at the tumor level) genomic changes, copy number variations (CNVs), epigenetic modifications, and differential expression of miRNAs, add to the variable genetic background of PAs.

Gonadotrophin-releasing hormone agonist-induced pituitary adenoma apoplexy and casual finding of a parathyroid carcinoma: A case report and review of literature

BACKGROUND

Pituitary apoplexy represents one of the most serious, life threatening endocrine emergencies that requires immediate management. Gonadotropin-releasing hormone agonist (GnRHa) can induce pituitary apoplexy in those patients who have insidious pituitary adenoma coincidentally.

CASE SUMMARY

A 46-year-old woman, with a history of hypertension and menorrhagia was transferred to our hospital from a secondary care hospital after complaints of headache and vomiting, with loss of consciousness 5 min after an injection of GnRHa. The drug was prescribed by her gynecologist due to the presence of uterine myomas. The clinical neurological examination revealed right cranial nerve III palsy, ptosis and movement limitation of the right eye. Our first clinical consideration was a pituitary apoplexy. Blood hormonal analysis revealed mild hyperprolactinemia and high follicle stimulating hormone level; PTH and calcium was high with glomerular filtration rate mildly to moderately decrease. A computed tomography scan, revealed an enlarged pituitary gland (3.5 cm) impinging upon the optic chiasm with bone involvement of the sella. Following contrast media administration, the lesion showed homogeneous enhancement with high-density focus that suggests hemorrhagic infarction of the tumor. Transsphenoidal endoscopic surgery was perfomed and adenomatous tissue was removed. Immunohistochemistry was positive for luteinizing hormone (LH) and follicular-stimulating hormone (FSH). A solid hypoechoic nodule (14 mm x 13 mm x 16 mm) was found in the caudal portion of the right thyroid lobe after a parathyroid ultrasound. A genetic test of Multiple Endocrine Neoplasia type 1 (MEN1) was negative. A right lower parathyroidectomy was performed and the pathologic study showed the presence of an encapsulated parathyroid carcinoma of 1.5 cm. A MEN type 4 genetic test was performed result was negative.

CONCLUSION

This case demonstrates an uncommon complication of GnRH agonist therapy in the setting of a pituitary macroadenoma and the casual finding of parathyroid carcinoma. It also highlights the importance of suspecting the presence of a multiple endocrine neoplasia syndrome and to carry out relevant genetic studies.