von Recklinghausen's disease and pheochromocytomas

A case of malignant pheochromocytoma with neurofibromatosis type 1 having difficulty in differentiating spinal tumor

Introduction

Neurofibromatosis type 1 is a hereditary condition often associated with pheochromocytomas but rarely with malignant pheochromocytomas. Neurofibromatosis type 1 is often associated with bone lesions, which complicates the distinction between malignant and benign tumors.

Case presentation

A 46-year-old man with a medical history of neurofibromatosis type 1 presented with right abdominal pain. Computed tomography revealed a right adrenal tumor, and metaiodobenzylguanidine scintigraphy showed accumulation in the right adrenal gland and thoracic vertebrae. He was diagnosed with pheochromocytoma, and a right adrenalectomy was performed. After surgery, a bone biopsy was conducted on the spinal lesion, confirming metastasis of pheochromocytoma, prompting irradiation. After that, lung and liver metastases emerged, and chemotherapy with cyclophosphamide, vincristine, and dacarbazine was initiated; however, the disease progressed, and he died 11 months after surgery.

Conclusion

We report a case of malignant pheochromocytoma associated with neurofibromatosis type 1 in which bone metastasis was difficult to diagnose.

Endocrine and non-endocrine causes of fatigue in adults with Neurofibromatosis type 1

Context

Neurofibromatosis type 1 (NF1) is a complex system disorder, caused by alterations in RAS pathways. NF1 adults often suffer from chronic and severe fatigue, for which they are frequently referred to Internal Medicine/Endocrinology. Seeking medical help often leads to (invasive) diagnostic procedures. To prevent the personal and financial burden of this disabling fatigue, it is crucial to know the causes.

Objective

To explore somatic causes and provide practical recommendations for the approach to fatigue in adults with NF1.

Design

Cross-sectional. All adults with NF1 (N = 133) who visited our Endocrinology department underwent a systematic health screening, including a medical questionnaire, structured interview, complete physical examination, biochemical measurements and additional tests if indicated.

Main outcome measure

Prevalence of endocrine and non-endocrine health problems between NF1 adults with and without fatigue.

Results

In our cohort, 75% of NF1 adults experienced fatigue. The most frequent endocrine disorders were vitamin D deficiency (28%), obesity (18%) and hypothyroidism (8%). The most frequent non-endocrine internal disorder was high blood pressure (42%). None of the disorders differed significantly between adults with and without fatigue.

Conclusions

Endocrine and non-endocrine disorders were equally present in our cohort of NF1 adults with and without fatigue. This suggests that the high prevalence of fatigue in NF1 adults is not explained by these somatic disorders. An alternative explanation for fatigue might be deficits in cognitive functioning and other neuropsychological processes in NF1. Based on our results and review of the literature, we provide a clinical algorithm for the approach to fatigue in NF1 adults, including somatic and psychological assessment.

Metanephrine negative pheochromocytoma: a rare case report of dopamine-secreting tumor in an adolescent neurofibromatosis type 1 patient

Pheochromocytoma (PCC) occurs in 4% of pediatric neurofibromatosis type 1 (NF1) patients and is characterized by epinephrine and norepinephrine secretion. Herein, we report the first case of dopamine-secreting PCC in a 13-year-old patient with NF1. A left adrenal mass was incidentally found on abdominal computed tomography (CT ) during hypertension workup. Fractionated 24-hour urine metanephrine excretion was normal, but urine dopamine level was elevated. Focal 123I-metaiodobenzylguanidine uptake was observed on single-photon emission tomography/CT (SPECT/CT). Surgery was delayed due to small tumor size, vague symptoms, and increased dopamine level. After 6 months, focal significant uptake of the lesion on 6-[18F]fluoro-L-3,4-dihydroxyphenylalanine (18F-FDOPA) PET/CT increased and tumor size increased on abdominal CT. Laparoscopic resection was performed, and the mass was histologically confirmed as PCC. Currently, the vital signs of the patient are stable, urine dopamine level is normal, and there is no abnormal uptake of 18F-FDOPA PET/CT. This study reports a rare case of dopamine-secreting PCC. A multidisciplinary approach and focused examination are needed in metanephrine-negative, high-risk PCC patients.

Biochemical Assessment of Pheochromocytoma and Paraganglioma

Pheochromocytoma and paraganglioma (PPGL) require prompt consideration and efficient diagnosis and treatment to minimize associated morbidity and mortality. Once considered, appropriate biochemical testing is key to diagnosis. Advances in understanding catecholamine metabolism have clarified why measurements of the O-methylated catecholamine metabolites rather than the catecholamines themselves are important for effective diagnosis. These metabolites, normetanephrine and metanephrine, produced respectively from norepinephrine and epinephrine, can be measured in plasma or urine, with choice according to available methods or presentation of patients. For patients with signs and symptoms of catecholamine excess, either test will invariably establish the diagnosis, whereas the plasma test provides higher sensitivity than urinary metanephrines for patients screened due to an incidentaloma or genetic predisposition, particularly for small tumors or in patients with an asymptomatic presentation. Additional measurements of plasma methoxytyramine can be important for some tumors, such as paragangliomas, and for surveillance of patients at risk of metastatic disease. Avoidance of false-positive test results is best achieved by plasma measurements with appropriate reference intervals and preanalytical precautions, including sampling blood in the fully supine position. Follow-up of positive results, including optimization of preanalytics for repeat tests or whether to proceed directly to anatomic imaging or confirmatory clonidine tests, depends on the test results, which can also suggest likely size, adrenal vs extra-adrenal location, underlying biology, or even metastatic involvement of a suspected tumor. Modern biochemical testing now makes diagnosis of PPGL relatively simple. Integration of artificial intelligence into the process should make it possible to fine-tune these advances.

Prevalence of Endocrine Manifestations and GIST in 108 Systematically Screened Patients With Neurofibromatosis Type 1

Context

In patients with neurofibromatosis type 1 (NF1), guidelines suggest screening for pheochromocytoma by metanephrine measurement and abdominal imaging, which may lead to the discovery of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and their differential diagnosis, gastrointestinal stromal tumors (GISTs). Other endocrine manifestations such as follicular thyroid carcinoma and primary hyperparathyroidism have also been reported in a few cases.

Objective

This study aimed to describe prevalence and clinical presentation of these manifestations through systematic screening in a large cohort of patients.

Methods

In this monocentric retrospective study, 108 patients with NF1 were included and screened for endocrine manifestations and GISTs. Clinical, laboratory, molecular profile, pathology, and morphologic (abdominal computed tomography scan and/or magnetic resonance imaging) and functional imaging were collected.

Results

Twenty-four patients (22.2% of the cohort, 16 female, mean age 42.6 years) presented with pheochromocytomas that were unilateral in 65.5%, benign in 89.7%, and with a ganglioneural component in 20.7%. Three female patients (2.8% of the cohort, aged 42-63 years) presented with well-differentiated GEP-NETs, and 4 (3.7%) with GISTs. One patient had primary hyperparathyroidism, 1 patient had medullary microcarcinoma, and 16 patients had goiter, multinodular in 10 cases. There was no correlation between pheochromocytoma and other NF1 tumoral manifestations, nor correlations between pheochromocytoma and NF1 genotype, despite a familial clustering in one-third of patients.

Conclusion

The pheochromocytoma prevalence in this NF1 cohort was higher (>20%) than previously described, confirming the interest of systematic screening, especially in young women. The prevalence of GEP-NETs and GISTs was about 3%, respectively. No phenotype-genotype correlation was observed.

Co-occurrence of mutations in NF1 and other susceptibility genes in pheochromocytoma and paraganglioma

Introduction

The percentage of patients diagnosed with pheochromocytoma and paraganglioma (altogether PPGL) carrying known germline mutations in one of the over fifteen susceptibility genes identified to date has dramatically increased during the last two decades, accounting for up to 35-40% of PPGL patients. Moreover, the application of NGS to the diagnosis of PPGL detects unexpected co-occurrences of pathogenic allelic variants in different susceptibility genes.

Methods

Herein we uncover several cases with dual mutations in NF1 and other PPGL genes by targeted sequencing. We studied the molecular characteristics of the tumours with co-occurrent mutations, using omic tools to gain insight into the role of these events in tumour development.

Results

Amongst 23 patients carrying germline NF1 mutations, targeted sequencing revealed additional pathogenic germline variants in DLST (n=1) and MDH2 (n=2), and two somatic mutations in H3-3A and PRKAR1A. Three additional patients, with somatic mutations in NF1 were found carrying germline pathogenic mutations in SDHB or DLST, and a somatic truncating mutation in ATRX. Two of the cases with dual germline mutations showed multiple pheochromocytomas or extra-adrenal paragangliomas - an extremely rare clinical finding in NF1 patients. Transcriptional and methylation profiling and metabolite assessment showed an "intermediate signature" to suggest that both variants had a pathological role in tumour development.

Discussion

In conclusion, mutations affecting genes involved in different pathways (pseudohypoxic and receptor tyrosine kinase signalling) co-occurring in the same patient could provide a selective advantage for the development of PPGL, and explain the variable expressivity and incomplete penetrance observed in some patients.

An Uncommon Presentation of Pheochromocytoma in Neurofibromatosis Type 1 and the Importance of Long-Term Follow-Up

Neurofibromatosis type 1 (NFT1) is a disease caused by mutations in the tumor suppressor gene NF1. It is associated with a higher incidence of chromaffin cell tumors which are usually adrenal, unilateral and benign. The presence of these tumors during pregnancy is extremely rare and frequently associated with fatal outcomes. We report the case of a female patient with NFT1, who presented with paroxysmal spells of headache, palpitations, dizziness and pre-cordial discomfort, starting immediately after the delivery of her third child. Diagnostic work-up came to reveal a bilateral pheochromocytoma and the patient underwent bilateral adrenalectomy. Over 12 years after the initial surgery, metastatic disease was diagnosed, and a reintervention was performed. This is a rare presentation of bilateral malignant pheochromocytoma in a patient with NFT1, with postpartum occurrence of the first symptoms. This text focuses the important details and challenges found at each stage of diagnosis and follow-up.

[Pheochromocytoma associated with primary hyperparathyroidism and type 1 neurofibromatosis]

Neurofibromatosis type 1 (NF-1) is a predominantly inherited genetic disease with prevalence of 1 per 2500-3000 newborns and based on clear clinical criteria. In addition to common neurofibromas and gliomas of the visual pathways, these patients have a higher risk of various benign and malignant tumors throughout their lives including tumors of the central nervous system, membranes of peripheral nerves, gastrointestinal stromal tumors and leukemia. Endocrine diseases and neoplasms also occur in patients with NF-1 and can include extrarenal paraganglioma, primary hyperparathyroidism, gastroenteropancreatic neuroendocrine tumors, thyroid tumors and other adrenal neoplasms. We demonstrate multiple neuroendocrine neoplasia (MEN 2A) of neurofibromatosis type 1 combined with pheochromocytoma and primary hyperparathyroidism in a woman with a long history of palpitations, paroxysmal hypertension and osteoporosis. Biochemical analysis revealed severe hypercalcemia with elevated parathyroid hormone indicating primary hyperparathyroidism, as well as high fractionated normetanephrine and metanephrine in the urine as a sign of catecholamine-releasing pheochromocytoma/paraganglioma. Further scintigraphy revealed signs of solitary parathyroid adenoma causing primary hyperparathyroidism and right-sided pheochromocytoma. Clinical diagnosis of MEN-2 syndrome is based on combination of at least two major MEN-2-associated endocrine tumors. Resection of parathyroid adenoma and pheochromocytoma normalized biochemical parameters and blood pressure. Combination of pheochromocytoma with primary hyperparathyroidism and type 1 neurofibromatosis is discussed.

Challenges in Anaesthetic Management in a Case of Facial Plexiform Neurofibromatosis Posted for Debulking Surgery

A patient diagnosed with facial plexiform neurofibromatosis type 1 who is 18 years old and is scheduled for tumour resection and debulking surgery of his face is the subject of this study. The purpose of this paper is to describe the anaesthetic treatment that was administered to this patient. In addition, we analyze the relevant literature, with a particular emphasis on the implications of modifying neurofibromatosis to achieve anaesthesia. Our patient was found to have multiple huge tumours all over his face. When he first arrived, he experienced cervical instability as a result of the enormous mass on the back of his head and in the region of his scalp. He also expected to have difficulty maintaining an airway and breathing through a bag and mask. To protect the patient's airway, a video laryngoscopy was performed, and a difficult airway cart was maintained on standby in the event it was required. In conclusion, the purpose of this case study was to demonstrate the relevance of comprehending the one-of-a-kind anaesthetic requirements of persons diagnosed with neurofibromatosis type 1 who are about to undergo surgical procedures. Neurofibromatosis is an extremely uncommon kind of disease that requires the anesthesiologist's undivided attention in surgical settings. Careful pre-operative planning and competent intra-operative treatment are required when dealing with patients who are expected to have difficult airway management.

Other Less Prevalent Tumors of the Central Nervous System

The presented tumors in this chapter are somewhat very rare, and their management is still debated due to the scarcity of information about their cell of origin, behavior, and biology. Treatment options are still limited, but we are confident that in the near future by discovering the genetic and biological mechanisms that drive tumor growth we will be able to offer new target therapies that should be flanked by surgery, radiotherapy, and chemotherapeutic agents actually in use. The purpose of this chapter is to highlight the most important known characteristics of these tumors offering the chance to recognize the disease and then offer the best opportunity for treatment to patients. The 5th WHO Classification Central Nervous System features substantial changes by moving further to advance the role of molecular diagnostics in CNS tumor classification, but remaining rooted in other established approaches to tumor characterization, including histology and immunohistochemistry, and probably, the category of many tumors will change. Here, the most important characteristics of each neoplasm are summarized focusing on genetic mechanisms and molecular pathways, their histopathologic footprints, signs and symptoms, radiologic features, therapeutic approaches, and prognosis as well as follow-up protocols. Schematic classifications are also presented to offer a better understanding of the pathology.

Bibliometric analysis of the top 100 most-cited articles in neurofibromatosis

Background:

Neurofibromatosis (NF) is an umbrella term that refers to three distinct disease entities: NF Type 1, Type 2, and schwannomatosis. Here, we reviewed the scientific performance and the most influential publications on NF.

Methods:

A keyword-based search was performed using the Scopus database. The top 100 articles were grouped based on NF types and the studied entities. The differences between the articles, authors, and journals were quantified based on certain parameters. Other parameters were collected for the complete citational analysis.

Results:

The top 100 articles were published between 1961 and 2020. The most trending period of research was in the 1990s and articles studying the clinical aspect and the underlying genetic correlation made up 84% of all articles from the list. The United States of America (USA) had the highest number of contributions (69 articles, 69%). The top institute of contribution to the list was the Howard Hughes Medical Institute, USA (14 articles, 14%). Author-based analysis reveals that the neurologist D. H. Gutmann from St. Louis Children’s Hospital, USA, was the most active and authored 11 articles (11%) on the list.

Conclusion:

The publication trends show that articles studying medical and surgical management were of little interest. The top 100 articles did not include any randomized control trials, and the highest level of evidence was obtained from reviews of pooled knowledge as well as population-based and longitudinal studies.

Neurofibromatosis from Head to Toe: What the Radiologist Needs to Know

Neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2) are autosomal dominant inherited neurocutaneous disorders or phakomatoses secondary to mutations in the NF1 and NF2 tumor suppressor genes, respectively. Although they share a common name, NF1 and NF2 are distinct disorders with a wide range of multisystem manifestations that include benign and malignant tumors. Imaging plays an essential role in diagnosis, surveillance, and management of individuals with NF1 and NF2. Therefore, it is crucial for radiologists to be familiar with the imaging features of NF1 and NF2 to allow prompt diagnosis and appropriate management. Key manifestations of NF1 include café-au-lait macules, axillary or inguinal freckling, neurofibromas or plexiform neurofibromas, optic pathway gliomas, Lisch nodules, and osseous lesions such as sphenoid dysplasia, all of which are considered diagnostic features of NF1. Other manifestations include focal areas of signal intensity in the brain, low-grade gliomas, interstitial lung disease, various abdominopelvic neoplasms, scoliosis, and vascular dysplasia. The various NF1-associated abdominopelvic neoplasms can be categorized by their cellular origin: neurogenic neoplasms, interstitial cells of Cajal neoplasms, neuroendocrine neoplasms, and embryonal neoplasms. Malignant peripheral nerve sheath tumors and intracranial tumors are the leading contributors to mortality in NF1. Classic manifestations of NF2 include schwannomas, meningiomas, and ependymomas. However, NF2 may have shared cutaneous manifestations with NF1. Lifelong multidisciplinary management is critical for patients with either disease. The authors highlight the genetics and molecular pathogenesis, clinical and pathologic features, imaging manifestations, and multidisciplinary management and surveillance of NF1 and NF2. Online supplemental material is available for this article. ^©RSNA, 2022.

Improved renal function in neurofibromatosis type 1 patients

Neurofibromatosis type 1 (NF1), or von Recklinghausen disease, is an autosomal dominant disease that presents with various symptoms, including café‐au‐lait spots and neurofibromas. NF1 patients occasionally suffer from renal artery vasculopathy, which impairs renal function, while results of a previous report suggested that male NF1 patients have a low creatinine level in peripheral blood. The assessment of renal function in NF1 patients remains inadequate. In this study, renal function in NF1 was assessed. We recruited 308 patients consisting of 149 NF1 patients (77 males and 72 females) and 159 control patients (102 males and 57 females). Creatinine, blood urea nitrogen and haemoglobin A1c in peripheral blood as well as protein, occult blood and sugar in urine were examined. In addition, the estimated glomerular filtration rate was calculated. The mean age and body mass index did not differ significantly between the NF1 patients and controls for both sexes. For both sexes, i) the mean creatinine value was significantly lower in the NF1 patients than in the controls; ii) the mean blood urea nitrogen value did not differ significantly between the NF1 patients and controls; iii) the mean blood urea nitrogen‐to‐creatinine ratio was significantly higher in the NF1 patients than in the controls; iv) the mean estimated glomerular filtration rate was significantly higher in the NF1 patients than in the controls; and v) the mean haemoglobin A1c value was significantly lower in the NF1 patients than in the controls. In conclusion, NF1 patients may have improved renal function. The clinical significances should be further examined.

When a Multidisciplinary Approach Is Life-Saving: A Case Report of Cardiogenic Shock Induced by a Large Pheochromocytoma

BACKGROUND

Pheochromocytoma is known for its instantaneous presentation, especially in the younger population. Hemodynamic instability may be the cause of severe complications and impede patients' ability to undergo surgical treatment. These tumours are surgically difficult to treat due to the risk of catecholamine release during their manipulations, and when they are large, the tumour size represents an additional challenge. In our report, cardiogenic shock developed due to increases in systemic vascular resistance, and the lesion's size induced surgeons to perform open surgery.

CASE PRESENTATION

A 46-year-old female patient was admitted to our intensive care unit with hypertension and later cardiogenic shock. Systolic dysfunction was noted, along with severely increased systemic vascular resistance. A CT scan showed a left-sided 8.5 cm adrenal mass, which was confirmed as pheochromocytoma using meta-iodobenzylguanidine scintigraphy. Anaesthesiologists and the surgical team planned an effective strategy of treatment. Given the lesion's size and its apparent invasion of the neighbouring organs, open adrenalectomy (after prolonged hemodynamic stabilisation) was considered safer. The surgery was successful, and the patient remains free from disease two years after the initial event.

CONCLUSIONS

Large pheochromocytoma can be safely and effectively treated with open surgery by experienced hands but only by seeking to reach hemodynamic stabilisation and minimising the release of catecholamine before and during surgery.

The RASopathies: Biology, genetics and therapeutic options

The RASopathies are a group of genetic diseases in which the Ras/MAPK signaling pathway is inappropriately activated as a result of mutations in genes encoding proteins within this pathway. As their causative mutations have been identified, this group of diseases has expanded to include neurofibromatosis type 1 (NF1), Legius syndrome, Noonan syndrome, CBL syndrome, Noonan syndrome-like disorder with loose anagen hair, Noonan syndrome with multiple lentigines, Costello syndrome, cardiofaciocutaneous syndrome, gingival fibromatosis and capillary malformation-arteriovenous malformation syndrome. Many of these genetic disorders share clinical features in common such as abnormal facies, short stature, varying degrees of cognitive impairment, cardiovascular abnormalities, skeletal abnormalities and a predisposition to develop benign and malignant neoplasms. Others are more dissimilar, even though their mutations are in the same gene that is mutated in a different RASopathy. Here, we describe the clinical features of each RASopathy and contrast them with the other RASopathies. We discuss the genetics of these disorders, including the causative mutations for each RASopathy, the impact that these mutations have on the function of an individual protein and how this dysregulates the Ras/MAPK signaling pathway. As several of these individual disorders are genetically heterogeneous, we also consider the different genes that can be mutated to produce disease with the same phenotype. We also discuss how our growing understanding of dysregulated Ras/MAPK signaling had led to the development of new therapeutic agents and what work will be critically important in the future to improve the lives of patients with RASopathies.

Pediatric Metastatic Pheochromocytoma and Paraganglioma: Clinical Presentation and Diagnosis, Genetics, and Therapeutic Approaches

Although pediatric pheochromocytomas and paragangliomas (PPGLs) are rare, they have important differences compared to those in adults. Unfortunately, without timely diagnosis and management, these tumors have a potentially devastating impact on pediatric patients. Pediatric PPGLs are more often extra-adrenal, multifocal/metastatic, and recurrent, likely due to these tumors being more commonly due to a genetic predisposition than in adults. This genetic risk results in disease manifestations at an earlier age giving these tumors time to advance before detection. In spite of these problematic features, advances in the molecular and biochemical characterization of PPGLs have heralded an age of increasingly personalized medicine. An understanding of the genetic basis for an individual patient's tumor provides insight into its natural history and can guide clinicians in management of this challenging disease. In pediatric PPGLs, mutations in genes related to pseudohypoxia are most commonly seen, including the von Hippel-Lindau gene (VHL) and succinate dehydrogenase subunit (SDHx) genes, with the highest risk for metastatic disease associated with variants in SDHB and SDHA. Such pathogenic variants are associated with a noradrenergic biochemical phenotype with resultant sustained catecholamine release and therefore persistent symptoms. This is in contrast to paroxysmal symptoms (e.g., episodic hypertension, palpitations, and diaphoresis/flushing) as seen in the adrenergic, or epinephrine-predominant, biochemical phenotype (due to episodic catecholamine release) that is commonly observed in adults. Additionally, PPGLs in children more often present with signs and symptoms of catecholamine excess. Therefore, children, adolescents, and young adults present differently from older adults (e.g., the prototypical presentation of palpitations, perspiration, and pounding headaches in the setting of an isolated adrenal mass). These presentations are a direct result of genetic determinants and highlight the need for pediatricians to recognize these differences in order to expedite appropriate evaluations, including genetic testing. Identification and familiarity with causative genes inform surveillance and treatment strategies to improve outcomes in pediatric patients with PPGL.

Neurofibromatosis and HIV infection in a pregnant woman

Although pregnant neurofibromatosis or HIV patient established a high-risk group, this report demonstrated that a careful planning and widespread valuations should be associated with a favorable prognosis for both mother and newborn.

A Novel, Likely Pathogenic MAX Germline Variant in a Patient With Unilateral Pheochromocytoma

Context

Inherited MYC-associated factor X (MAX) gene pathogenic variants (PVs) increase risk for pheochromocytomas (PCCs) and/or paragangliomas (PGLs) in adults and children. There is little clinical experience with such mutations.

Objective

This report highlights an important approach.

Methods

Clinical assessment, including blood chemistry, imaging studies, and genetic testing were performed.

Results

A 38-year-old Hispanic woman was diagnosed with PCC in 2015, treated with adrenalectomy, and referred to endocrinology clinic. Notably, she presented to her primary care physician 3 years earlier complaining of left flank pain, intermittent diaphoresis, and holocranial severe headache. We confirmed severe hypertension (180/100 mm Hg) over multiple antihypertensive regimens. Biochemical and radiological studies workup revealed high plasma metanephrine of 255 pg/mL (normal range, < 65 pg/mL) and plasma normetanephrine of 240 pg/mL (normal range, < 196 pg/mL). A noncontrast computed tomography scan of the abdomen revealed a 4.2 × 4.3 × 4.9-cm, round-shaped and heterogenous contrast enhancement of the left adrenal gland, and a 2-mm nonobstructive left kidney stone. A presumptive diagnosis of secondary hypertension was made. After pharmacological therapy, laparoscopic left adrenalectomy was performed and confirmed the diagnosis of pheochromocytoma. Based on her age, family history, and a high suspicion for genetic etiology, genetic testing was performed that revealed the presence of a novel likely pathogenic variant involving a splice consensus sequence in the MAX gene, designated c0.64-2A > G.

Conclusion

The phenotype of MAX PV-related disease and paraganglioma are highlighted. The novel c0.64-2A > G mutation is reported here and should be considered in the diagnostic workup of similar cases.

Genetics of pheochromocytoma and paraganglioma

PURPOSE OF REVIEW

This review summarizes our current understanding of germline and somatic genetics and genomics of pheochromocytomas and paragangliomas (PCC/PGL), describes existing knowledge gaps, and discusses future research directions.

RECENT FINDINGS

Germline pathogenic variants (PVs) are found in up to 40% of those with PCC/PGL. Tumors with germline PVs are broadly categorized as Cluster 1 (pseudohypoxia), including those with SDH, VHL, FH, and EPAS1 PVs, or Cluster 2 (kinase signaling) including those with NF1, RET, TMEM127, and MAX PVs. Somatic driver mutations exist in some of the same genes (RET, VHL, NF1, EPAS1) as well as in additional genes including HRAS, CSDE1 and genes involved in cell immortalization (ATRX and TERT). Other somatic driver events include recurrent fusion genes involving MAML3.

SUMMARY

PCC/PGL have the highest association with germline PVs of all human solid tumors. Expanding our understanding of the molecular pathogenesis of PCC/PGL is essential to advancements in diagnosis and surveillance and the development of novel therapies for these unique tumors.

Case report of a man with multiple paragangliomas and pathogenic germline variants in both NF1 and SDHD

We report a novel case of multiple paragangliomas in a patient who was identified with pathogenic variants in both NF1 and SDHD genes. The proband is a man with known familial NF1 disease, diagnosed clinically in childhood. Multiple head and neck paragangliomas (HNPGL) were found during investigations for acute left sided neurological symptoms, in the region of his known plexiform neurofibroma. He was referred for genetic counselling. He underwent surgery to remove a left carotid body tumor (CBT). A pheochromocytoma and paraganglioma gene panel was tested. Blood and HNPGL tumor DNA were analyzed by whole exome sequencing. In addition to the NF1 truncating variant c.5107delA, p.(Ser1703AlafsTer7), the SDHD truncating pathogenic variant c.3G > A, p.(Met1?) was found. Tumor sequencing showed no LOH of SDHD or NF1, but monoallelic loss of 11p15 and 11q12.2-q12.3 was observed. Co-occurrence of pathogenic variants in multiple cancer susceptibility genes is rare but possible, identified by the increased use of panel testing. This is the first description of a patient presenting with NF1 and SDHD dual pathology, with HNPGL development due to SDHD. This case illustrates the central role of genetic sequencing in PPGLs and the strong genotype-phenotype correlations of different genes.

Association between pheochromocytoma and neurofibromatosis type I: a rare entity in the African population

The association of pheochromocytoma in patients with neurofibromatosis type I has rarely been reported in low-income countries, especially on the African continent. A 43-year-old woman with neurofibromatosis type I was diagnosed with a right adrenal pheochromocytoma in Pretoria, South Africa. To our knowledge, this report is the first case to be published of a patient with neurofibromatosis type I diagnosed with a pheochromocytoma in Pretoria, and one of three cases on the African continent. The rarity may be due to the two associated conditions being under-reported, undiagnosed, misdiagnosed or possibly the association is rare on the African continent. The clinician dealing with these two conditions should be aware of the association.

Phakomatoses and Endocrine Gland Tumors: Noteworthy and (Not so) Rare Associations

Phakomatoses encompass a group of rare genetic diseases, such as von Hippel-Lindau syndrome (VHL), neurofibromatosis type 1 (NF1), tuberous sclerosis complex (TSC) and Cowden syndrome (CS). These disorders are due to molecular abnormalities on the RAS-PI3K-Akt-mTOR pathway for NF1, TSC and CS, and to hypoxia sensing for VHL. Phakomatoses share some phenotypic traits such as neurological, ophthalmological and cutaneous features. Patients with these diseases are also predisposed to developing multiple endocrine tissue tumors, e.g., pheochromocytomas/paragangliomas are frequent in VHL and NF1. All forms of phakomatoses except CS may be associated with digestive neuroendocrine tumors. More rarely, thyroid cancer and pituitary or parathyroid adenomas have been reported. These susceptibilities are noteworthy, because their occurrence rate, prognosis and management differ slightly from the sporadic forms. The aim of this review is to summarize current knowledge on endocrine glands tumors associated with VHL, NF1, TSC, and CS, especially neuroendocrine tumors and pheochromocytomas/paragangliomas. We particularly detail recent advances concerning prognosis and management, especially parenchyma-sparing surgery and medical targeted therapies such as mTOR, MEK and HIF-2 α inhibitors, which have shown truly encouraging results.

Screening for Hereditary Pheochromocytoma in a Patient with Neurofibromatosis Type 1: A Case Report

Pheochromocytoma (PHEO) is a rare tumour that arises from adreno-medullary chromaffin cells and secretes catecholamines. These hormones are also secreted by paragangliomas, which derive from extra-adrenal cells of the sympathetic paravertebral ganglia. At least one-third of PHEOs are familial. Neurofibromatosis type 1 (NF1), or von Recklinghausen's disease, is diagnosed upon clinical criteria, and the study of PHEO is advised if hypertension is present. The incidence of PHEO in NF1 is 0.1-5.7% and explains hypertension in 20-50% of these patients. Recent advances in the treatment of this condition and preoperative preparation allow us to reduce its high cardiovascular morbimortality. Here we present the case of a 31-year-old female with known NF1 who presented with 5 months' history of non-specific symptoms and an episode of intraoperative hypertensive crisis. The workup detected a left sided PHEO, which was treated surgically. Our case illustrates the high prevalence of hereditary PHEO and how its presentation can go unnoticed. It reinforces the significance of screening for PHEO in patients with NF1.

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.

Pheochromocytoma crisis in a patient with newly diagnosed neurofibromatosis type 1

Pheochromocytoma occasionally engenders catecholamine-induced hypertension crisis. Pheochromocytoma is clinically identified in 0.1%-5.7% of patients with neurofibromatosis type 1 (NF1), which is 10 times more frequently than in healthy individuals. This report describes a case of newly diagnosed NF1 presenting with pheochromocytoma crisis, with severe electrolyte depletion and deteriorating recurrent ventricular tachycardia storm. Characteristic skin lesions such as café-au-lait macules and neurofibromas contributed to the diagnosis of NF1 and pheochromocytoma. No recurrence of electrolyte depletion was found after the adrenalectomy. Primary care physicians must distinguish the characteristic skin lesions of NF1, such as café-au-lait macules and neurofibromas and recognise the risk for pheochromocytoma.

Neurofibromatosis Type 1 with Concurrent Multiple Endocrine Disorders: Adenomatous Goiter, Primary Hyperparathyroidism, and Acromegaly

We encountered a 70-year-old Japanese woman with neurofibromatosis type 1 (NF1) who had a history of pheochromocytoma and concurrently developed adenomatous goiter, primary hyperparathyroidism, and acromegaly. The patient had a somatotroph adenoma of the adenohypophysis that predisposed her to multinodular goiter. Three parathyroid tumors were detected by cervical ultrasonography and cervicothoracic computed tomography. Genetic analyses did not reveal genetic alterations (e.g. loss-of-function mutation) in the causative genes of endocrine tumors, including MEN1, RET, VHL, CDKN1B, and CDKN2C. The NF1 gene could not be analyzed genetically due to the patient's refusal. The pathophysiologic mechanisms of endocrinopathy concurrence in NF1 remain to be elucidated.

Screening for Hereditary Pheochromocytoma in a Patient with Neurofibromatosis Type 1: A Case Report

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Imaging Features of Neurofibromatosis Type 1 in the Abdomen and Pelvis

OBJECTIVE. Loss of the neurofibromatosis type 1 (NF1) tumor suppressor protein causes uninhibited activation of the RAS oncogene, which leads to tumorigenesis in patients with NF1. This case-based review discusses imaging manifestations of NF1 in the abdomen and pelvis, highlighting key genetic associations and management to elucidate features different from the general population. CONCLUSION. The spectrum of pathologic findings includes gastrointestinal tumors such as gastrointestinal stromal tumors, genitourinary lesions including urogenital neurofibromas, vascular entities such as renal artery stenosis, and less common associations like lymphoma.

Complex Vascular Revascularization in a Young Woman with Type 1 Neurofibromatosis

We present an uncommon case of a 16-year-old woman with type 1 neurofibromatosis and renovascular hypertension due to bilateral renal stenosis associated with asymptomatic digestive artery stenosis. Our patient was treated by several autologous bypasses to the superior mesenteric artery and the left and right renal arteries. She had no postoperative complications and good clinical and imaging outcomes at 10 years. Furthermore, there are few data on the vascular impairment of this rare disease, thus justifying its presentation.

Understanding the Biological Activities of Vitamin D in Type 1 Neurofibromatosis: New Insights into Disease Pathogenesis and Therapeutic Design

Vitamin D is a fat-soluble steroid hormone playing a pivotal role in calcium and phosphate homeostasis as well as in bone health. Vitamin D levels are not exclusively dependent on food intake. Indeed, the endogenous production-occurring in the skin and dependent on sun exposure-contributes to the majority amount of vitamin D present in the body. Since vitamin D receptors (VDRs) are ubiquitous and drive the expression of hundreds of genes, the interest in vitamin D has tremendously grown and its role in different diseases has been extensively studied. Several investigations indicated that vitamin D action extends far beyond bone health and calcium metabolism, showing broad effects on a variety of critical illnesses, including cancer, infections, cardiovascular and autoimmune diseases. Epidemiological studies indicated that low circulating vitamin D levels inversely correlate with cutaneous manifestations and bone abnormalities, clinical hallmarks of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumour predisposition syndrome causing significant pain and morbidity, for which limited treatment options are available. In this context, vitamin D or its analogues have been used to treat both skin and bone lesions in NF1 patients, alone or combined with other therapeutic agents. Here we provide an overview of vitamin D, its characteristic nutritional properties relevant for health benefits and its role in NF1 disorder. We focus on preclinical and clinical studies that demonstrated the clinical correlation between vitamin D status and NF1 disease, thus providing important insights into disease pathogenesis and new opportunities for targeted therapy.

Paragangliomas Throughout the Body: Hereditary Syndromes and Imaging Features Including 3D Cinematic Rendering

Paragangliomas are highly vascular neuroendocrine tumors that arise from embryonic neural crest cells. They may either be hormonally active (sympathetic) or silent (parasympathetic). Approximately one-third are hereditary, and patients may develop multiple paragangliomas. Presurgical planning involves medical management as well as interventional and/or surgical techniques that must address vascular supply. Contrast-enhanced CT is the best initial anatomical study and shows the hypervascularity and feeding vessels. 3D cinematic rendering using multiplanar light sources can highlight spatial relationships of a mass to adjacent structures and help in surgical planning. This article will review the clinical presentation of paragangliomas, genetic syndromes, presurgical management, and tumor behavior and imaging appearance by location with a particular emphasis on 3D cinematic rendering.

Pheochromocytoma Multisystem Crisis and Masquerading Disseminated Histoplasmosis in a Neurofibromatosis Type 1 Patient With Bilateral Adrenal Tumors

Pheochromocytomas are rare catecholamine-secreting neuroendocrine tumors that can occasionally progress to life-threatening disease, including a multisystem crisis. Patients with Neurofibromatosis type 1 (NF1) may develop pheochromocytomas, and the consequent chronic elevation of plasma catecholamine levels could further complicate various cardiovascular and pulmonary manifestations they may have. A 37-year-old African American female with NF1 presented with severe dyspnea, chills, myalgia, vomiting, and abdominal pain. Within several hours of hospital admission, she developed progressive agitation and died from circulatory collapse. An autopsy revealed disseminated histoplasmosis with necrotizing granulomatosis in her lungs, mediastinum, liver, and spleen, as well as bilateral pheochromocytomas with one tumor showing marked hemorrhage. Additionally, she had cardiac hypertrophy, myocarditis, pulmonary edema, apical bullae, features of pulmonary hypertension and interstitial fibrosis. Disseminated histoplasmosis caused by the fungal organism Histoplasma capsulatum is rarely described in immunocompetent individuals. This case is presented to illustrate that chronic hypercatecholaminemia caused by pheochromocytomas may potentially mask disseminated fungal infections which in turn could induce pheochromocytoma multisystem crisis in susceptible patients with neurofibromatosis.

Neurofibromatosis Type 1 with the Development of Pheochromocytoma and Breast Cancer

A 40-year-old woman presented with a left adrenal incidentaloma. Based on the presence of café-au-lait spots, cutaneous neurofibroma, and family history, she was diagnosed with neurofibromatosis type 1 (NF1). Adrenal incidentaloma screening showed an elevated normetanephrine level; the left adrenal mass showed the uptake of I-123 meta-iodobenzylguanidine. She underwent left adrenalectomy, and pheochromocytoma was diagnosed. One year later, the results of a biopsy of a palpable mass in the left breast suggested invasive ductal carcinoma. The patient underwent neoadjuvant chemotherapy followed by left breast-conserving surgery. We herein report a rare case of an NF1 patient who developed both pheochromocytoma and breast cancer.

Pheochromocytoma and gastrointestinal stromal tumours in an adult neurofibromatosis type 1 patient: a rare co-occurrence

The risk of tumours including pheochromocytoma and gastrointestinal stromal tumour (GIST) has been reported to be higher in neurofibromatosis type 1 (NF1) patients. The concomitant occurrence of these two tumours was rare in NF1 patient and most were symptomatic. In this case report, we describe the case of a 47-year-old man with NF1 who presented with microscopic haematuria. Neither hypertension nor any gastrointestinal symptoms were reported by the patient. While investigating for haematuria, left adrenal mass and arterial enhancing lesions in the small bowel were incidentally documented during computerised urography. The patient subsequently underwent a left adrenalectomy and small bowel resection. The pheochromocytoma and multiple GIST tumours were diagnosed based on pathology. Here, we discuss the rare association of pheochromocytoma and GIST and the asymptomatic presentation of those tumours in an NF1 patient. We further suggest that in NF1 patients a heightened level of vigilance can help identify this infrequent combination.

Abdominal neoplastic manifestations of neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant hereditary tumor syndrome, with a wide clinicopathologic spectrum. It is defined by characteristic central nervous system, cutaneous and osseous manifestations, and by mutations in the NF1 gene, which is involved in proliferation via p21, RAS, and MAP kinase pathways. Up to 25% of NF1 patients develop intra-abdominal neoplastic manifestations including neurogenic (commonly plexiform neurofibromas and malignant peripheral nerve sheath tumors), interstitial cells of Cajal (hyperplasia, gastrointestinal stromal tumors), neuroendocrine, and embryonal tumors (rhabdomyosarcoma). Nonspecific symptoms, multifocal disease, or coexistence of 2 or more tumor types make patients challenging to diagnose and manage. Screening for intra-abdominal tumors in NF1 patients remains controversial, and currently no guidelines are established. Management decisions are complex and often informed by single-center experiences or case studies in the literature, though the field is rapidly evolving. Thus, NF1 patients should be followed in specialist centers familiar with their wide spectrum of pathology and with multidisciplinary care including specialized pathology and radiology. This review will (1) provide a contemporaneous synthesis of the literature and our multi-institutional clinical experiences with intra-abdominal neoplasms in NF1 patients, (2) present a classification framework for this heterogeneous group of disorders, and (3) outline approaches to screening, surveillance, diagnosis, and management.

Co-occurrence of neurofibromatosis type 1 and optic nerve gliomas with autosomal dominant polycystic kidney disease type 2

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) and neurofibromatosis type 1 (NF1) are both autosomal dominant disorders with a high rate of novel mutations. However, the two disorders have distinct and well-delineated genetic, biochemical, and clinical findings. Only a few cases of coexistence of ADPKD and NF1 in a single individual have been reported, but the possible implications of this association are unknown.

METHODS

We report an ADPKD male belonging to a family of several affected members in three generations associated with NF1 and optic pathway gliomas. The clinical diagnosis of ADPKD and NF1 was performed by several image techniques.

RESULTS

Linkage analysis of ADPKD family was consistent to the PKD2 locus by a nonsense mutation, yielding a truncated polycystin-2 by means of next-generation sequencing. The diagnosis of NF1 was confirmed by mutational analysis of this gene showing a 4-bp deletion, resulting in a truncated neurofibromin, as well. The impact of this association was investigated by analyzing putative genetic interactions and by comparing the evolution of renal size and function in the proband with his older brother with ADPKD without NF1 and with ADPKD cohorts.

CONCLUSION

Despite the presence of both conditions there was not additive effect of NF1 and PKD2 in terms of the severity of tumor development and/or ADPKD progression.

‘Adrenal rush’ in a patient with Neurofibromatosis-1

Neurofibromatosis-1 (NF-1) is a genetic neuro-cutaneous disorder that is associated with an increased prevalence of pheochromocytoma (PHEO). However, this association may not be commonly anticipated by physicians, as patients may be normotensive. In addition, NF-1 patients can be asymptomatic and/or normotensive. These factors can result in a delayed or missed diagnosis of pheochromocytoma leading to catastrophic complications. Currently, it is recommended to perform annual blood pressure monitoring in patients with NF-1 and to test for pheochromocytoma only if found to be hypertensive. However, recent studies show that this practice may lead to underdiagnosis of pheochromocytoma. Therefore, suggesting routine biochemical testing for pheochromocytoma in all patients with NF-1.

In this case report, we discuss the factors which can lead to a delayed diagnosis of pheochromocytoma in a patient with known NF-1 and hypertension.

Detection of severe hypertension in a patient with neurofibromatosis type 1 during anesthesia induction: a case report

Background

Neurofibromatosis type 1 has a higher prevalence of pheochromocytoma and paraganglioma than the general population: 1.0–5.7% versus 0.2–0.6%. Currently, there are no generally accepted guidelines for screening for pheochromocytoma and paragangliomas in asymptomatic patients with neurofibromatosis type 1.

Case presentation

Severe hypertension developed during anesthesia induction in our patient, a 44-year-old Chinese man with neurofibromatosis type 1. We screened for catecholamine level after glioma resection, and the patient was diagnosed with combined pheochromocytoma and paraganglioma.

Conclusions

A delay in diagnosis or lack of a diagnosis in pheochromocytoma and paraganglioma may increase the perioperative morbidity and mortality risk due to excess catecholamine secretion. Therefore, routine pheochromocytoma and paraganglioma screening preoperatively in patients with neurofibromatosis type 1 is very important.

Ewing sarcoma in a child with neurofibromatosis type 1

We report here on a case of Ewing sarcoma (ES) occurring in a child with neurofibromatosis type 1. The sarcoma had an EWSR1-ERG translocation as well as loss of the remaining wild-type allele of NF1. Loss of the NF1 wild-type allele in the tumor suggests that activation of the Ras pathway contributed to its evolution. Review of available public data suggests that secondary mutations in the Ras pathway are found in ∼3% of ESs. This case suggests that Ras pathway activation may play a role in tumor progression in a subset of ESs.

Glioblastoma in adults with neurofibromatosis type I: A report of two cases

Neurofibromatosis type I (NF1) is a familial tumor syndrome with an autosomal-dominant inheritance. NF1-associated tumors often include neurofibromas, malignant peripheral nerve sheath tumors and pilocytic astrocytomas of the optic nerve. The presentation of NF1 patients with glioblastoma is a rare occurrence, with only a handful of cases reported in the literature. We report two cases of glioblastomas occurring in adults with NF1 and briefly review the relevant literature.

Clinical Presentation and Outcomes of Phaeochromocytomas/Paragangliomas in Neurofibromatosis Type 1

Introduction: Patients with neurofibromatosis type 1 (NF1) are at risk of developing phaeochromocytomas/paragangliomas (PHAEO/PG). Unlike in other familial PHAEO/PG syndromes, there are no published guidelines regarding screening in asymptomatic or normotensive patients with NF1. This strategy may be associated with preventable morbidities in those patients who ultimately present with symptomatic PHAEO/PG. Objective: To describe the mode of presentation and the incidence of adverse clinical outcomes attributed to PHAEO/PG in NF1. Methods: A retrospective study was performed in a tertiary referral centre in collaboration with a national complex NF1 centre. Hospital records and databases between 1998–2018 were searched. Results: Twenty-seven patients with NF1 and PHAEO/PG were identified. In all but one, PHAEO/PG was diagnosed after NF1. The median age at the time of diagnosis of PHAEO/PG was 43 years (range 22–65) and 21/27 (78%) were females. The diagnosis was mostly incidental in 13/27 (48%) while classical PHAEO/PG symptoms were found in 15/27 (56%), and hypertension was found in 14/27 (52%) of NF1 patients prior to PHAEO/PG diagnosis. No patient had undergone biochemical screening for PHAEO/PG. Metastatic disease was evident in 2/27 patients, 8 suffered potentially avoidable complications attributed to PHAEO/PG (including two deaths). Conclusion: The course of PHAEO/PG in NF1 is associated with an unpredictable presentation and potentially avoidable adverse outcomes. We recommend that routine biochemical screening for PHAEO/PG should be part of the care package offered to all patients with NF1 by regular measurements of plasma free or urinary fractionated metanephrines starting from early adolescence and repeated every 3 years.

Pheochromocytoma/Paraganglioma: Is This a Genetic Disorder?

Pheochromocytomas and paragangliomas (PCC/PGL) are neuroendocrine tumors of the adrenal medulla and extra-adrenal ganglia which often over-secrete catecholamines leading to cardiovascular morbidity and even mortality. These unique tumors have the highest heritability of all solid tumor types with up to 35-40% of patients with PCC/PGL having a germline predisposition. PURPOSE OF REVIEW: To review the germline susceptibility genes and clinical syndromes associated with PCC/PGL. RECENT FINDINGS: There are over 12 PCC/PGL susceptibility genes identified in a wide range of pathways. Each gene is associated with a clinical syndrome with varying penetrance for both primary and metastatic PCC/PGL and often includes increased risk for additional tumors besides PCC/PGL. Patients with sporadic or hereditary PCC/PGL should be monitored for life given the risk of multiple primary tumors, recurrence, and metastatic disease. All patients with PCC/PGL should be referred for consideration for clinical genetic testing given the high heritability of disease.

Precision Surgery for Pheochromocytomas and Paragangliomas

Since Felix Fränkel's account of pheochromocytoma in 1886, great discoveries and vast advancements in the diagnosis, genetics, anatomical and functional imaging techniques, and surgical management of pheochromcytoma and paraganglioma (P-PGL) have been made. The improved insight in the pathophysiology of P-PGL and more accurate detection methods enable physicians to tailor the treatment plan to an individual based on the genetic profile and tumor behavior. This review will cover briefly the clinical features, diagnosis, genetic mutations, and imaging modalities that are used to guide current surgical management of these rare and interesting endocrinopathies.

Recent Advances in the Diagnosis and Pathogenesis of Neurofibromatosis Type 1 (NF1)-associated Peripheral Nervous System Neoplasms

The diagnosis of a neurofibroma or a malignant peripheral nerve sheath tumor (MPNST) often raises the question of whether the patient has the genetic disorder neurofibromatosis type 1 (NF1) as well as how this will impact the patient's outcome, what their risk is for developing additional neoplasms and whether treatment options differ for NF1-associated and sporadic peripheral nerve sheath tumors. Establishing a diagnosis of NF1 is challenging as this disorder has numerous neoplastic and non-neoplastic manifestations which are variably present in individual patients. Further, other genetic diseases affecting the Ras signaling cascade (RASopathies) mimic many of the clinical features of NF1. Here, we review the clinical manifestations of NF1 and compare and contrast them with those of the RASopathies. We also consider current approaches to genetic testing for germline NF1 mutations. We then focus on NF1-associated neurofibromas, considering first the complicated clinical behavior and pathology of these neoplasms and then discussing our current understanding of the genomic abnormalities that drive their pathogenesis, including the mutations encountered in atypical neurofibromas. As several neurofibroma subtypes are capable of undergoing malignant transformation to become MPNSTs, we compare and contrast patient outcomes in sporadic, NF1-associated and radiation-induced MPNSTs, and review the challenging pathology of these lesions. The mutations involved in neurofibroma-MPNST progression, including the recent identification of mutations affecting epigenetic regulators, are then considered. Finally, we explore how our current understanding of neurofibroma and MPNST pathogenesis is informing the design of new therapies for these neoplasms.

Phaeochromocytoma/paraganglioma and adverse clinical outcomes in patients with neurofibromatosis-1

INTRODUCTION

Phaeochromocytomas/paragangliomas (PHAEO/PG) are linked to hereditary syndromes including neurofibromatosis type 1 (NF-1). Current guidelines do not recommend biochemical screening for PHAEO/PG in asymptomatic or normotensive patients with NF-1. This strategy may miss preventable morbidities in those patients who ultimately present with symptomatic PHAEO/PG. Our aim was to review the literature and extract data on mode of presentation and the incidence of reported adverse outcomes.

METHODS

PubMed and EMBASE literature search using the keywords "Phaeochromocytoma", "Paraganglioma" and "Neurofibromatosis" was performed looking for reported cases from 2000 to 2018.

RESULTS

73 reports of NF-1 patients with PHAEO/PG were found. Patients were predominately women (n=40) with a median age of 46 years (range 16-82). PHAEO/PG was found incidentally in most patients, 36/73 did not present with typical symptoms while 27 patients were normotensive at diagnosis. 31 patients had adverse outcomes including metastases and death.

CONCLUSION

Given the protean presentation of PHAEO/PG, relying on symptomology and blood pressure status as triggers for screening is associated with adverse outcomes. Further studies are required to ascertain whether biochemical screening in asymptomatic and normotensive patients with NF-1 can reduce the rate of adverse outcomes.

65 YEARS OF THE DOUBLE HELIX: Endocrine tumour syndromes in children and adolescents

As medicine is poised to be transformed by incorporating genetic data in its daily practice, it is essential that clinicians familiarise themselves with the information that is now available from more than 50 years of genetic discoveries that continue unabated and increase by the day. Endocrinology has always stood at the forefront of what is called today 'precision medicine': genetic disorders of the pituitary and the adrenal glands were among the first to be molecularly elucidated in the 1980s. The discovery of two endocrine-related genes, GNAS and RET, both identified in the late 1980s, contributed greatly in the understanding of cancer and its progression. The use of RET mutation testing for the management of medullary thyroid cancer was among the first and one of most successful applications of genetics in informing clinical decisions in an individualised manner, in this case by preventing cancer or guiding the choice of tyrosine kinase inhibitors in cancer treatment. New information emerges every day in the genetics or system biology of endocrine disorders. This review goes over most of these discoveries and the known endocrine tumour syndromes. We cover key genetic developments for each disease and provide information that can be used by the clinician in daily practice.

An Autopsy Case of Sudden Death in Neurofibromatosis Type 1 With Pheochromocytoma and Myocarditis

An autopsy case of sudden death in a 33-year-old man with neurofibromatosis type 1 (von Recklinghausen disease), pheochromocytoma, and myocarditis is reported. The decedent was found in his bedroom in cardiopulmonary arrest. Polypoid, elastic dermal papules on the neck, chest, abdomen, and back, and flat dark-brown macules on the chest and abdomen were observed. Flat, ovoid, dark-brown freckles were present in both axillae. Examination of the right adrenal gland revealed a tumor measuring 5 cm × 5 cm × 3 cm. Microscopic examination of the myocardium revealed moderate neutrophilic and lymphocytic infiltrates. In the right adrenal gland, tumor cells contained abundant granular eosinophilic cytoplasm and exhibited cell-nesting with an alveolar pattern (Zellballen). Polygonal cells were seen together with rich vascular networks. Immunohistochemical analyses showed cells diffusely positive for chromogranin A and dopamine β-hydroxylase. Furthermore, blood from the right heart and the right common iliac vein contained high concentrations of serum epinephrine, norepinephrine, and dopamine. Death was attributed to adrenal crisis: circulatory failure caused by excessive catecholamines produced by the pheochromocytoma. In addition, myocarditis, which had been induced chronically by catecholamines, would have also contributed adversely to the clinical course. Pheochromocytoma and myocarditis should be considered when sudden death occurs in the setting of neurofibromatosis type 1.