Health supervision for children with neurofibromatosis

Neurofibromatosis type 1 - an update

Neurofibromatosis type 1 (NF1) is one of the most common genetic conditions. It can be inherited in an autosomal dominant manner, but almost half of cases occur de novo. NF1 is associated with café-au-lait macules, freckles in the inguinal and axillary region, neurofibromas, Lisch nodules of the iris or choroidal abnormalities, optic pathway gliomas, and distinctive bone anomalies. It has complete penetrance but highly variable disease manifestations. Certain features including café-au-lait macules, bony abnormalities, and optic pathway gliomas emerge by early childhood, but others appear later in life. A cure for NF1 has not been found, however emerging treatments have involved modulation of the RAS/MAPK signaling pathway.

Quality of Life in Children and Adolescents with Neurofibromatosis Type 1: A Single-Center Observational Study

This article obtains an overview of the health status of children and adolescents with neurofibromatosis type 1 (NF1) with a focus on the clinical course of the disease, neuropsychodiagnostic findings, and their impact on quality of life (QoL). In this observational study, data were collected from 24 children and adolescents with NF1 who were cared for at the University Hospital in Innsbruck, Austria, from 2008 to 2022. Data were collected every 6 to 12 months from routine check-ups, including clinical features and imaging findings. Results of neuropsychodiagnostic tests and the KINDL questionnaire to assess QoL were included. Of 24 patients, 15 underwent a neuropsychological examination. Attention performance was examined in 11 of them. Eight of 11 (72%) showed an attention deficit. Assessment for specific developmental disorders showed visual-spatial difficulties in 12/15 (80%) patients. The KINDL questionnaire values ranged from 58.22 to 97.92 (0 stands for reduced QoL, 100 for very good QoL). Patients with scoliosis had a lower range of QoL (56.33-73.96). No trend in QoL was observed in children and adolescents with plexiform neurofibromas, below-average intelligence or optic gliomas. NF1 patients show very different clinical courses. Regular neuropsychological assessment especially with regard to visual-spatial skills and attention deficits is necessary to offer appropriate support, promote children's development, and thus improve their QoL.

Neurofibromatosis Type 1-Associated Optic Pathway Gliomas: Current Challenges and Future Prospects

Optic pathway glioma (OPG) occurs in as many as one-fifth of individuals with the neurofibromatosis type 1 (NF1) cancer predisposition syndrome. Generally considered low-grade and slow growing, many children with NF1-OPGs remain asymptomatic. However, due to their location within the optic pathway, ~20-30% of those harboring NF1-OPGs will experience symptoms, including progressive vision loss, proptosis, diplopia, and precocious puberty. While treatment with conventional chemotherapy is largely effective at attenuating tumor growth, it is not clear whether there is much long-term recovery of visual function. Additionally, because these tumors predominantly affect young children, there are unique challenges to NF1-OPG diagnosis, monitoring, and longitudinal management. Over the past two decades, the employment of authenticated genetically engineered Nf1-OPG mouse models have provided key insights into the function of the NF1 protein, neurofibromin, as well as the molecular and cellular pathways that contribute to optic gliomagenesis. Findings from these studies have resulted in the identification of new molecular targets whose inhibition blocks murine Nf1-OPG growth in preclinical studies. Some of these promising compounds have now entered into early clinical trials. Future research focused on defining the determinants that underlie optic glioma initiation, expansion, and tumor-induced optic nerve injury will pave the way to personalized risk assessment strategies, improved tumor monitoring, and optimized treatment plans for children with NF1-OPG.

Current update on the visual outcome of optic pathway glioma associated with neurofibromatosis type-1

Purpose

Clinical and diagnostic evaluation in the follow-up of optic glioma patients with neurofibromatosis type 1 (NF-1) can be difficult. Determining whether and when to provide treatment is a significant challenge in best managing these patients. Update on current information and future directions in management is included in this review.

Current Practice

NF-associated optic pathway gliomas (OPGs) present a significant management challenge with high stakes for visual outcomes. Monitoring vision and diagnostic tests are challenging in patients of a younger age. Regardless of whether few or many optic gliomas are encountered during clinical practice.

Summary

This review of optic gliomas-NF1-associated gliomas includes the current approach and knowledge of OPG-NF1 and future directions in OPG-NF1 management. This includes the ongoing Multicenter Natural History Study and other clinical trials and outcomes in NF-1 patients with OPG.

Scoliosis Secondary to Neurofibromatosis Type I Combined With Moyamoya Syndrome: A Case Report

CASE

A 13-year-old girl presenting with scoliosis accompanied by type I neurofibromatosis (NF1) underwent deformity correction surgery. On the second postoperative day, she had sudden-onset acute cerebral infarctions and was diagnosed with moyamoya syndrome. After neurological conservative treatment, at the sixth month after surgery, her symptoms and signs were significantly improved and the daily life was not affected by herself.

CONCLUSION

NF1 scoliosis with moyamoya syndrome is an uncommon inherited disorder. Intracranial vasculopathy is hardly detected from routine preoperative examinations. The specific intracranial vascular examination should be performed for patients with NF1 scoliosis, especially those who have a positive history of cerebral ischemic or hemorrhagic symptoms.

Optic Pathway Glioma in Children with Neurofibromatosis Type 1: A Multidisciplinary Entity, Posing Dilemmas in Diagnosis and Management Multidisciplinary Management of Optic Pathway Glioma in Children with Neurofibromatosis Type 1

Introduction

Neurofibromatosis type 1 (NF1) has an incidence of 1 in 2,000 to 3,000 individuals and in 15% is associated with optic pathway glioma (OPG). Given the variability in clinical presentation and related morbidity, a multidisciplinary approach for diagnosis and management of children with NF1 and OPG is required, but often lacks coordination and regular information exchange. Herein we summarize our experience and describe the care pathways/network provided by a multidisciplinary team. The role of the distinct team members is elucidated as well as the care amendments made over time.

Methods

We performed a retrospective single-center observational study, including children treated at our institution between 1990 and 2021. Inclusion criteria were clinical diagnosis of NF1, radiographic and/or histopathological diagnosis of OPG and age below 18 years. Patients being treated elsewhere were excluded from the study. Data was abstracted from each child’s health record using a standardized data collection form. Characteristics of children with NF1 and OPG were described using means (SD) and percentages. Outcomes were determined using Kaplan-Meier estimates.

Results

From 1990 to 2021, 1,337 children were followed in our institution. Of those, 195 were diagnosed with OPG (14.6%), including 94 (48.21%) females and 101 (51.79%) males. Comprehensive data were available in 150 patients. The mean (SD) age at diagnosis was 5.31(4.08) years (range: 0.8–17.04 years). Sixty-two (41.3%) patients remained stable and did not undergo treatment, whereas 88 (58.7%) patients required at least one treatment. The mean (SD) duration of follow up was 8.14 (5.46) years (range: 0.1–25.9 years; median 6.8 years). Overall survival was of 23.6 years (±1.08), comprising 5 deaths. A dedicated NF clinic, including pediatricians and a nurse, provides regular follow up and plays a central role in the management of children with NF1, identifying those at risk of OPG, coordinating referrals to Neuroradiology and other specialists as indicated. All children are assessed annually by Ophthalmology. Comprehensive care was provided by a multidisciplinary team consisting of Dermatology, Genetics, Neuro-oncology, Neuroradiology, Neurosurgery, Ophthalmology and Pediatrics.

Conclusions

The care of children with NF1 and OPG is optimized with a multidisciplinary team approach, coordinated by a central specialty clinic.

A Case Series of Plexiform Neurofibroma: The Unusual Presentations and Surgical Challenges

Neurofibromatosis type one (NF-1) is an autosomal dominant neurocutaneous disorder also known as Von Recklinghausen disease. Plexiform neurofibroma is a rare kind of NF-1 where the neurofibroma originates from nerve sheath cells or subcutaneous peripheral nerves. It is pathognomonic of NF-1, and isolated occurrence is relatively rare. We reported three cases of solitary plexiform neurofibromas with an unusual presentation. We have two cases of spontaneous bleeding isolated plexiform neurofibroma that have never been reported in the literature. Neither one of them showed signs and symptoms associated with the neurofibromatosis spectrum. This unusual presentation poses substantial challenges in diagnosis and management.

Adolescents and young adults with neurofibromatosis type 1: A descriptive study of adaptive functioning

Neurofibromatosis type 1 (NF1) is a genetic syndrome affecting about 1 in 3500 individuals; many of those affected have plexiform neurofibroma (pNF) tumors and associated symptoms and complications. Furthermore, learning and attention problems, as well as deficits in adaptive functioning, are common, often beginning in early childhood. This study aimed to describe adaptive functioning and to examine relationships between adaptive functioning and cognitive and academic variables and level of independence among adolescents and young adults (AYA) with NF1 and pNF tumors. Fifty-five AYA aged 16-31 years participated in a series of neuropsychological evaluations while parents completed the Vineland Adaptive Behavior Scales (VABS-II) as part of a larger natural history study. Over one-third (35%) of AYA were neither in school nor employed. Mean VABS-II daily living and socialization scores were low average while mean Verbal and Performance IQ scores were average. VABS-II scores were positively correlated with processing speed, executive functioning, and working memory scores. Verbal IQ was the only significant predictor of work/school status. Identification of the correlates and predictors of adaptive functioning and life achievement can help guide healthcare providers with the early identification of risk factors and possible areas for intervention.

Imaging Evaluation of Plexiform Neurofibromas in Neurofibromatosis Type 1: A Survey-Based Assessment

OBJECTIVE

To assess imaging utilization practices across clinical specialists in neurofibromatosis type 1 (NF1) for the evaluation of symptomatic and asymptomatic children and adults with or without plexiform neurofibromas (PN).

METHODS

An institutional review board-exempt survey was administered to medical practitioners caring for individuals with NF1 at the Response Evaluation in Neurofibromatosis and Schwannomatosis (REiNS) meeting in September 2019. The survey included questions on respondent demographic data (9 questions), type of imaging obtained for asymptomatic (4 questions) and symptomatic (4 questions) people with and without PN, and utilization of diffusion-weighted imaging (2 questions).

RESULTS

Thirty practitioners participated in the survey. Most were academic neuro-oncologists at high-volume (>10 patients/week) NF1 centers. Of 30 respondents, 26 had access to whole-body MRI (WB-MRI). The most common approach to an asymptomatic person without PN was no imaging (adults: 57% [17/30]; children: 50% [15/30]), followed by a screening WB-MRI (adults: 20% [6/30]; children: 26.7% [8/30]). The most common approach to a person with symptoms or known PN was regional MRI (adults: 90% [27/30]; children: 93% [28/30]), followed by WB-MRI (adults: 20% [6/30]; children: 36.7% [11/30]). WB-MRI was most often obtained to evaluate a symptomatic child with PN (37% [11/30]).

CONCLUSIONS

More than 90% of practitioners indicated they would obtain a regional MRI in a symptomatic patient without known or visible PN. Otherwise, there was little consensus on imaging practices. Given the high prevalence of PN and risk of malignant conversion in this patient population, there is a need to define imaging-based guidelines for optimal clinical care and the design of future clinical trials.

Contralateral Breast Cancer With Multiple Primary Neoplasms in a Patient With Neurofibromatosis Type 1: A Case Report and Review of the Literature

Neurofibromatosis type 1 (NF1) is an autosomal dominant neuroectodermal disorder associated with increased risk for several neural and non-neural malignancies. The link between NF1 and breast cancer has recently been established, with patients with NF1 being at higher risk for developing breast cancer, more likely to get breast cancer at a younger age, and more likely to have their breast cancer present with more adverse prognostic factors. Although rare, several cases of NF1 patients with contralateral breast cancer have been mentioned in the literature. We report the case of one such patient who developed contralateral breast cancer 40 years after her initial breast cancer diagnosis.

Genetic syndromes predisposing to pediatric brain tumors

The application of high-throughput sequencing approaches including paired tumor/normal sampling with therapeutic intent has demonstrated that 8%-19% of pediatric CNS tumor patients harbor a germline alteration in a classical tumor predisposition gene (NF1, P53). In addition, large-scale germline sequencing studies in unselected cohorts of pediatric neuro-oncology patients have demonstrated novel candidate tumor predisposition genes (ELP1 alterations in sonic hedgehog medulloblastoma). Therefore, the possibility of an underlying tumor predisposition syndrome (TPS) should be considered in all pediatric patients diagnosed with a CNS tumor which carries critical implications including accurate prognostication, selection of optimal therapy, screening, risk reduction, and family planning. The Pediatric Cancer Working Group of the American Association for Cancer Research (AACR) recently published consensus screening recommendations for children with the most common TPS. In this review, we provide an overview of the most relevant as well as recently identified TPS associated with the most frequently encountered pediatric CNS tumors with an emphasis on pathogenesis, genetic testing, clinical features, and treatment implications.

Subclavian Artery Branch Pseudoaneurysm Rupture With Massive Hemothorax in a Patient With Neurofibromatosis Type 1

Neurofibromatosis type 1 is a rare disorder that occurs secondary to pathogenic variants in the NF1 tumor suppressor gene on chromosome 17. Characteristic clinical manifestations include multiple hyperpigmented macules, axillary and inguinal freckling, optic gliomas, and numerous skin neurofibromas. Vasculopathies are a rare complication of this disease and can affect vessels ranging from the proximal aorta to small arterioles, with pathology including arterial stenosis, aneurysms, and arteriovenous malformations. Aneurysms in these patients are often asymptomatic, and most patients with this complication appear for treatment after vessel rupture. We describe a 33-year-old man with neurofibromatosis type 1 who presented with chest pain and was ultimately found to have a ruptured left subclavian artery branch pseudoaneurysm leading to a large hemothorax.

Genetic predisposition in pediatric oncology

Identifying patients with a genetic predisposition for developing malignant tumors has a significant impact on both the patient and family. Recognition of genetic predisposition, before diagnosing a malignant pathology, may lead to early diagnosis of a neoplasia. Recognition of a genetic predisposition syndrome after the diagnosis of neoplasia can result in a change of treatment plan, a specific follow-up of adverse treatment effects and, of course, a long-term follow-up focusing on the early detection of a second neoplasia.

Responsible for genetic syndromes that predispose individuals to malignant pathology are germline mutations. These mutations are present in all cells of conception, they can be inherited or can occur de novo.

Several mechanisms of inheritance are described: Mendelian autosomal dominant, Mendelian autosomal recessive, X-linked patterns, constitutional chromosomal abnormality and non-Mendelian inheritance.

In the following review we will present the most important genetic syndromes in pediatric oncology.

Lisch nodules and iris mammillations in two siblings with familial legius syndrome

Legius syndrome is characterized by numerous café‐au‐lait macules and intertriginous freckling, but typically lacks the distinctive tumor manifestations of neurofibromatosis type 1. We report two siblings with Legius syndrome and Lisch nodules illustrating the importance of eye surveillance in these patients.

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.

Factors associated with parental knowledge of neurofibromatosis type 1 (NF1): Parental affected status and genetic counseling

Neurofibromatosis type 1 (NF1) is a genetic condition characterized by various cutaneous, neurological and psychological manifestations. The present study examined whether parental knowledge of NF1 is associated with a parent's NF1 status, affected or unaffected, and exposure to genetic counseling. Parents of children with NF1 were invited to complete an online survey answering true or false and multiple-choice questions to evaluate their overall knowledge of NF1. The study included 274 respondents, of which NF1 knowledge scores were significantly higher for unaffected parents (p < .001), and for parents who reported previously meeting with a genetic counselor (p < .001). Items pertaining to NF1-related cancer were least likely to be answered correctly. The results of the current study revealed lower overall NF1 knowledge in affected parents and knowledge gaps identifying areas where focused NF1 education may be beneficial.

An overview of 20 years of genetic studies in pheochromocytoma and paraganglioma

Paragangliomas and pheochromocytomas (PPGL) are rare neuroendocrine tumours characterized by a strong genetic determinism. Over the past 20 years, evolution of PPGL genetics has revealed that around 40% of PPGL are genetically determined, secondary to a germline mutation in one of more than twenty susceptibility genes reported so far. More than half of the mutations occur in one of the SDHx genes (SDHA, SDHB, SDHC, SDHD, SDHAF2), which encode the different subunits and assembly protein of a mitochondrial enzyme, succinate dehydrogenase. These susceptibility genes predispose to early forms (VHL, RET, SDHD, EPAS1, DLST), syndromic (RET, VHL, EPAS1, NF1, FH), multiple (SDHD, TMEM127, MAX, DLST, MDH2, GOT2) or malignant (SDHB, FH, SLC25A11) PPGL. The discovery of a germline mutation in one of these genes changes the patient's follow-up and allows genetic screening of affected families and the presymptomatic follow-up of relatives carrying a mutation.

Phakomatoses

Phakomatoses present with characteristic findings on the skin, central or peripheral nervous system, and tumors. Neurofibromatosis type 1 is the most common syndrome and is characterized by Café-au-lait macules, intertriginous freckling, Lisch nodules, and tumors including neurofibromas, malignant peripheral nerve sheath tumors, and gliomas. Tuberous Sclerosis Complex is characterized by benign hamartomas presenting with hypomelanotic macules, shagreen patches, angiofibromas, confetti lesions and tumors including cortical tubers, subependymal nodules, subependymal giant cell astrocytomas and tumors of the kidney, lung, and heart. Managing these disorders requires disease specific supportive care, tumor monitoring, surveillance for selected cancers, and treatment of comorbid conditions.

Café au Lait Macules and Associated Genetic Syndromes

Café au lait macules (CALMs) are a common, isolated dermatologic finding in the general population. But when do these irregularly shaped, jagged-edged, flat, hyperpigmented birthmarks suggest something that may warrant referral? Most pediatric providers are familiar with the association of CALMs and neurofibromatosis type 1. There are, however, other genetic conditions associated with these seemingly benign skin spots. This article provides an overview of CALMs, followed by a summary of several conditions associated with CALMs ranging from the most common (neurofibromatosis type 1) to rare, ring chromosome syndromes. It reviews the associated gene(s), pattern of inheritance, incidence, presenting symptoms, diagnosis, and management for these genetic conditions.

The Diagnosis and Management of Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1), NF2, and schwannomatosis are related, but distinct, tumor suppressor syndromes characterized by a predilection for tumors in the central and peripheral nervous systems. NF1 is one of the most common autosomal dominant conditions of the nervous system. NF1 has a high degree of variability in clinical presentation, which may include multiple neoplasms as well as cutaneous, vascular, bony, and cognitive features. Some of these manifestations overlap with other genetic conditions. Accurate diagnosis of NF1 is important for individualizing clinical care and genetic counseling. This article summarizes the clinical features, diagnostic work-up, and management of NF1.

Dysfunctional coping is related to impaired skin-related quality of life and psychological distress in patients with neurofibromatosis type 1 with major skin involvement

BACKGROUND

Low skin-related quality of life (QoL) is usually associated with low levels of self-confidence and self-esteem and with high levels of anxiety and depression symptoms. The way patients cope with a physical disease impacts significantly on their psychosocial adjustment to the disorder and on their emotional functioning.

OBJECTIVES

To explore how coping strategies, skin-related QoL, psychological distress and self-esteem interact in a sample of individuals with neurofibromatosis type 1 (NF1).

METHODS

Seventy-two adult patients with NF1 completed the following questionnaires: Coping Orientation to Problem Experiences (COPE), Skindex-29, Padua Skin-Related QoL questionnaire (PSRQ), State-Trait Anxiety Inventory-X2 form (STAI-X2), Depression Questionnaire (DQ) and Rosenberg Self-Esteem Scale (RSES). The k-modes algorithm was used to identify clusters of patients based on four variables: sex, NF1 severity, number and distribution of cutaneous neurofibromas. Individuals in different clusters were compared with regard to their scores; correlations between scores were analysed within each cluster.

RESULTS

Two main clusters were identified: individuals in Cluster 1 had a larger number and more widespread distribution of neurofibromas compared with Cluster 2. Patients in Cluster 1 scored higher only on several PSRQ and Skindex-29 scales. Among patients in Cluster 1, the COPE 'avoidance strategies' scale was significantly correlated with the PSRQ 'physical distress and impairments' scale, the Skindex-29 'physical symptoms' and 'functioning' scales, the STAI-X2, the DQ and the RSES.

CONCLUSIONS

Patients with major skin involvement have reduced skin-related QoL. Among them, current findings tentatively suggest that the higher the use of dysfunctional coping, the more impaired are QoL, psychological distress and self-esteem. What's already known about this topic? Neurofibromatosis type 1 (NF1) can affect the quality of life (QoL) in adolescent and adult patients. Low skin-related QoL is usually associated with low levels of self-confidence and self-esteem and with high levels of anxiety and depression symptoms. Questionnaires evaluating skin-related QoL, anxiety, depression, self-esteem and coping are available. What does this study add? Patients with a large number and a widespread distribution of cutaneous neurofibromas have reduced skin-related QoL compared with patients with minor skin involvement. The newly developed Padua Skin-Related QoL questionnaire allows the simultaneous evaluation of discomfort and comfort skin-related QoL dimensions in patients with NF1. Among patients with major skin involvement, the higher the use of dysfunctional coping, the more impaired are skin-related QoL, psychological distress and self-esteem. Our data suggest that patients with NF1 with major skin involvement who endorse dysfunctional beliefs about their own coping abilities might benefit from psychological counselling and coping skills treatments aiming to both improve perceived self-efficacy and learn more adaptive coping strategies.

Development of a multidisciplinary clinic of neurofibromatosis type 1 and other neurocutaneous disorders in Greece. A 3-year experience

Given the complexity of neurocutaneous syndromes, a multidisciplinary approach has been advocated in order to provide optimum care. Subjects and Methods: Retrospective analysis of a cohort of 157 patients during a 3-year period, seen at a newly developed neurocutaneous clinic in a pediatric tertiary care hospital in Athens (Greece); and systematic chart review of the patients diagnosed with neurofibromatosis type 1 during this time period. Results: The most frequent neurocutaneous syndromes were neurofibromatosis type 1 (NF1) in 89 patients and tuberous sclerosis complex in 17. In 20.38% of patients a neurocutaneous syndrome was not confirmed. Approximately 2/3 of the NF1 patients underwent genetic analysis, and for 76.67% of them, a pathogenic mutation on the NF1 gene was revealed. Eighty-one patients manifested with generalized NF1 and eight with mosaic NF1. Dermatological manifestations included café-au-lait macules in all patients, followed by axillary and/or inguinal freckling (n = 57), external plexiform neurofibromas (n = 17), and cutaneous and subcutaneous neurofibromas (n = 11). Approximately half of patients had learning disabilities and attention deficit hyperactivity disorder, followed by mental retardation (n = 9), autistic spectrum disorders (n = 4), headaches (n = 3) and seizures (n = 2). Neuroimaging showed characteristic areas of hyperintensity on T2-weighted images in 74.07% of patients and optic pathway glioma in 19.75%. Two patients developed malignant peripheral sheath nerve tumor. Conclusions: Neurocutaneous syndromes are clinically heterogeneous and the surveillance of potential clinical complications is challenging. The availability of genetic diagnosis and novel imaging methods in this group of disorders is likely to further expand their clinical spectrum. Guidelines for assessment and management will need to be modified based on new available data.

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.

Imaging biomarkers for malignant peripheral nerve sheath tumors in neurofibromatosis type 1

OBJECTIVE

To determine the utility of quantitative metrics obtained from fMRI using diffusion-weighted imaging (DWI)/apparent diffusion coefficient (ADC) mapping compared with metabolic (¹⁸F-fluorodeoxyglucose [FDG]-PET/CT) imaging in patients with neurofibromatosis type 1 (NF1) for the characterization of peripheral nerve sheath tumors (PNSTs) as benign or malignant.

METHODS

This Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant study retrospectively reviewed imaging of 55 PNSTs in 21 patients with NF1. Imaging included anatomic (unenhanced T1, fluid-sensitive, contrast-enhanced T1-weighted), functional DWI (b = 50, 400, 800 s/mm²) and ADC mapping, magnetic resonance sequences, and FDG-PET/CT imaging. Anatomic (size), functional (minimum ADC values), and metabolic (maximum standardized uptake values [SUVmax]) imaging characteristics were recorded. ADC values were correlated with SUVmax. With histologic correlation for all malignant PNSTs (MPNSTs) or clinical or imaging stability (>12 months) for benign lesions used as reference standards, diagnostic accuracy was calculated.

RESULTS

Of 55 PNSTs, there were 19 (35%) malignant and 36 (65%) benign PNSTs. Benign PNSTs were overall smaller than MPNSTs (largest diameter 4.3 ± 1.3 vs 8.2 ± 3.3 cm, respectively, p = 0.014). Benign PNSTs had higher ADCmin (×10^-3 mm²/s) than MPNSTs (1.6 ± 0.4 vs 0.6 ± 0.2, respectively, p < 0.0001) and lower SUVmax than MPNSTs (3.2 ± 1.8 vs 8 ± 3.9, p < 0.0001, respectively). ADCmin correlated inversely with SUVmax (correlation coefficient r = -0.0.58, p < 0.0001). Maintaining a sensitivity of 100% with threshold values of ADCmin ≤1 or SUVmax >3.2, DWI yielded a specificity of 94% while FDG-PET/CT offered a specificity of 83%.

CONCLUSIONS

Both quantitative metabolic imaging and functional imaging offer high sensitivity for the characterization of PNSTs in NF1; however, DWI/ADC mapping offers increased specificity and may be a more useful modality.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with NF1, MRI using DWI/ADC mapping accurately distinguishes malignant and benign PNSTs.

Health Supervision for Children With Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is a multisystem disorder that primarily involves the skin and peripheral nervous system. Its population prevalence is approximately 1 in 3000. The condition is usually recognized in early childhood, when pigmentary manifestations emerge. Although NF1 is associated with marked clinical variability, most children affected follow patterns of growth and development within the normal range. Some features of NF1 can be present at birth, but most manifestations emerge with age, necessitating periodic monitoring to address ongoing health and developmental needs and minimize the risk of serious medical complications. In this report, we provide a review of the clinical criteria needed to establish a diagnosis, the inheritance pattern of NF1, its major clinical and developmental manifestations, and guidelines for monitoring and providing intervention to maximize the health and quality of life of a child affected.

Can we differentiate malignant peripheral nerve sheath tumor from benign neurofibroma without invasive sampling

One of the most important benign tumors in neurofibromatosis type 1 (NF1) is plexiform neurofibroma, and there is a risk of developing malignant peripheral nerve sheath tumor (MPNST) throughout life approximately 10%. However lesion characterization by anatomical imaging methods are not possible. Because of that most of cases goes to biopsy. Using of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) for lesion characterization can be helpful in NF1 patients. We aimed to present an example of the efficacy of FDG-PET/CT in distinguishing benign neurofibroma from MPNST. A 6-year-old male patient who had NF1 admitted to emergency service due to high fever. Acute upper respiratory tract infection was diagnosed; antipyretic and abundant fluid intake was suggested. When high fever continued, the patient referred to our hospital on detection of axillary lymphadenopathy. Leukocytosis was detected in patient's blood count. Sedimentation was 54 mm/h, C-reactive protein 166 g/L, and lactate dehydrogenase 276U/L. Blood and throat cultures did not show pathogenic bacteria. In serological tests, VZV-IgG, EBV-VCA-IgG, and CMV-IgG were avidite positive; Hepatitis B Ag, Anti-HIV, Anti-HAV IgG and IgM, Anti-HCV, EBV-VCA IgM, and VZV-IgM were negative. Based on these results, cervical and thoracic contrast-enhanced computed tomography was performed on preliminary diagnosis of MPNST. Solid lesions with rounded margins, large one being 49 mm in size, that extend from superior mediastinum to posterior mediastinum, left axillary region, and left part of neck were detected, and they were surrounding the vascular structures. Since neurofibroma, MPNST, and lymphoma could not be distinguished, patient referred to FDG-PET/CT scanning. In FDG-PET/CT, highest lesion maximum standardized uptake value (SUV_max) was 1.5; SUV_max lesion/SUV_max liver 1.0, and SUV_max/ SUV mean liver 1.5. Biopsy from mediastinal and axillary region did not have LN structure and was positive for S-100 immunostaining, and patient was diagnosed as benign neurofibroma. We believe that there is no need for biopsy in lesions considered benign based on FDG-PET/CT parameters.

Rare NF1 microdeletion syndrome in an Omani patient

Neurofibromatosis-1 phenotype combined with webbed neck and short stature in a young Omani patient was revealed to be due to a de novo germ-line heterozygous 1.7 Mb microdeletion at 17q11.2. This lead to the diagnosis of NF1 microdeletion syndrome.

Translating genomic risk into an early detection strategy for sarcoma

Sarcomas have a strong genetic etiology, and the study of families affected by sarcomas has informed much of what we now understand of modern cancer biology. The recent emergence of powerful genetic technologies has led to astonishing reductions in costs and increased throughput. In the clinic, these technologies are revealing a previously unappreciated and rich landscape of genetic cancer risk. In addition to both known and new cancer risk mutations, genomic tools are cataloguing complex and polygenic risk patterns, collectively explaining between 15-25% of apparently sporadic sarcoma cases. The impact on clinical management is exemplified by Li-Fraumeni Syndrome, the most penetrant sarcoma syndrome. Whole body magnetic resonance imaging can identify surgically resectable cancers in up to one in ten individuals with Li-Fraumeni Syndrome. Taken together, parallel developments in genomics, therapeutics and imaging technologies will drive closer engagement between genetics and multidisciplinary care of the sarcoma patient in the 21st century.

Neurocutaneous Disorders

PURPOSE OF REVIEW

This article presents an up-to-date summary of the genetic etiology, diagnostic criteria, clinical features, and current management recommendations for the most common neurocutaneous disorders encountered in clinical adult and pediatric neurology practices.

RECENT FINDINGS

The phakomatoses are a phenotypically and genetically diverse group of multisystem disorders that primarily affect the skin and central nervous system. A greater understanding of the genetic and biological underpinnings of numerous neurocutaneous disorders has led to better clinical characterization, more refined diagnostic criteria, and improved treatments in neurofibromatosis type 1, Legius syndrome, neurofibromatosis type 2, Noonan syndrome with multiple lentigines, tuberous sclerosis complex, Sturge-Weber syndrome, and incontinentia pigmenti.

SUMMARY

Neurologists require a basic knowledge of and familiarity with a wide variety of neurocutaneous disorders because of the frequent involvement of the central and peripheral nervous systems. A simple routine skin examination can often open a broad differential diagnosis and lead to improved patient care.

Malignant peripheral nerve sheath tumours and neurofibromatosis 1: A case series and recommendations for care

Background: The incidence of malignant peripheral nerve sheath tumours (MPNST) in patients with neurofibromatosis 1 (NF1) is significantly higher than that of the general population. NF1-associated MPNST occur at a younger age and carry a worse prognosis than sporadic MPNST.Aim: This case series describes four cases of MPNST in patients with NF1.Setting: The study was performed in a public academic hospital in the Western Cape province of South Africa.Method: Demographics, disease status, histopathology, treatment and outcome data were collected retrospectively from medical charts and through review of histological slides.Results: The median age was 36.5 years. All tumours were > 5 cm at presentation and located on the trunk. One patient presented with metastatic disease. There was a mean delay of 3.5 months from presentation to initiation of treatment. Three patients underwent wide excision, with one receiving adjuvant chemotherapy and radiotherapy. At a median follow-up of 20 months from histological diagnosis only one patient was alive in clinical remission. Two patients had succumbed to progressive disease at 8 and 16 months from diagnosis and one patient with terminal metastatic disease was lost to follow-up.Conclusion: In this series the patients presented with advanced, often unresectable lesions for which single modality therapy was not curative. An adult NF1 health surveillance guideline for resource-constrained environments could lead to early diagnosis and treatment of MPNST and other complications in NF1 patients.

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.

Exome sequencing for paediatric-onset diseases: impact of the extensive involvement of medical geneticists in the diagnostic odyssey

Currently, offering whole-exome sequencing (WES) via collaboration with an external laboratory is increasingly common. However, the receipt of a WES report can be merely the beginning of a continuing exploration process rather than the end of the diagnostic odyssey. The laboratory often does not have the information the physician has, and any discrepancies in variant interpretation must be addressed by a medical geneticist. In this study, we performed diagnostic WES of 104 patients with paediatric-onset genetic diseases. The post-exome review of WES reports by the clinical geneticist led to a more comprehensive assessment of variant pathogenicity in 16 cases. The overall diagnostic yield was 41% (n = 43). Among these 43 diagnoses, 51% (22/43) of the pathogenic variants were nucleotide changes that have not been previously reported. The time required for the post-exome review of the WES reports varied, and 26% (n = 27) of the reports required an extensive amount of time (>3 h) for the geneticist to review. In this predominantly Chinese cohort, we highlight the importance of discrepancies between global and ethnic-specific frequencies of a genetic variant that complicate variant interpretation and the significance of post-exome diagnostic modalities in genetic diagnosis using WES. The challenges faced by geneticists in interpreting WES reports are also discussed.

In-depth reviews by clinical geneticists can improve the diagnostic accuracy of exome sequencing data for children with unexplained genetic disorders, especially in non-Western populations that are under-represented in genomic databases. Working with children predominantly of Han Chinese origin, Brian Chung from the University of Hong Kong and coworkers sequenced the entire protein-coding portion of the genome for 104 patients with pediatric-onset genetic disease. Specially trained geneticists analyzed the DNA data to resolve any ambiguous interpretations, link the molecular findings with clinical records, identify ethnic-specific differences and, when necessary, request additional assays. This extra review process was sometimes laborious, taking several hours of the physician’s time, but ultimately led to a more comprehensive assessment in 16 of the 43 diagnoses successfully made. This overall diagnostic yield—41%—was comparable to previous studies in other populations.

A porcine model of neurofibromatosis type 1 that mimics the human disease

Loss of the NF1 tumor suppressor gene causes the autosomal dominant condition, neurofibromatosis type 1 (NF1). Children and adults with NF1 suffer from pathologies including benign and malignant tumors to cognitive deficits, seizures, growth abnormalities, and peripheral neuropathies. NF1 encodes neurofibromin, a Ras-GTPase activating protein, and NF1 mutations result in hyperactivated Ras signaling in patients. Existing NF1 mutant mice mimic individual aspects of NF1, but none comprehensively models the disease. We describe a potentially novel Yucatan miniswine model bearing a heterozygotic mutation in NF1 (exon 42 deletion) orthologous to a mutation found in NF1 patients. NF1+/ex42del miniswine phenocopy the wide range of manifestations seen in NF1 patients, including café au lait spots, neurofibromas, axillary freckling, and neurological defects in learning and memory. Molecular analyses verified reduced neurofibromin expression in swine NF1+/ex42del fibroblasts, as well as hyperactivation of Ras, as measured by increased expression of its downstream effectors, phosphorylated ERK1/2, SIAH, and the checkpoint regulators p53 and p21. Consistent with altered pain signaling in NF1, dysregulation of calcium and sodium channels was observed in dorsal root ganglia expressing mutant NF1. Thus, these NF1+/ex42del miniswine recapitulate the disease and provide a unique, much-needed tool to advance the study and treatment of NF1.

Pediatric High Grade Gliomas in the Context of Cancer Predisposition Syndromes

Germline mutations in cancer causing genes result in high risk of developing cancer throughout life. These cancer predisposition syndromes (CPS) are especially prevalent in childhood brain tumors and impact both the patient’s and other family members’ survival. Knowledge of specific CPS may alter the management of the cancer, offer novel targeted therapies which may improve survival for these patients, and enables early detection of other malignancies. This review focuses on the role of CPS in pediatric high grade gliomas (PHGG), the deadliest group of childhood brain tumors. Genetic aspects and clinical features are depicted, allowing clinicians to identify and diagnose these syndromes. Challenges in the management of PHGG in the context of each CPS and the promise of innovative options of treatment and surveillance guidelines are discussed with the hope of improving outcome for individuals with these devastating syndromes.

Consequences of diagnosing a tumor predisposition syndrome in children with cancer: A literature review

Up to 8.5% of children with cancer have a genetic cause for their cancer: a tumor predisposition syndrome (TPS). Diagnosing a TPS is of great importance, as it may have major consequences for clinical care. Patients with TPSs require specific monitoring and management. We present an overview of the cancer-related and noncancer-related consequences for the 36 most common TPSs.

Developing Cervical Hematoma Following Jaw Thrust Maneuver Triggered Diagnosis of Neurofibromatosis: A Case Report and Brief Literature Review

A 25-year-old man underwent an excision of a thigh mass under general anesthesia without any complication. After the operation, he developed oxygen desaturation requiring a jaw thrust maneuver. A rapidly expanding hematoma on the right side of the neck was formed shortly after the application of the maneuver. The patient was returned to the operation room for a neck exploration. Damage to the facial artery and vein was noted. Further evaluations confirmed the diagnosis of Neurofibromatosis type 1 (NF-1). It is recommended that considering the probable risk of arising hematoma in NF-1 patients, application of jaw thrust maneuver should be performed meticulously.

Ophthalmic manifestations in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a relatively common multisystemic inherited disease and has been extensively studied by multiple disciplines. Although genetic testing and confirmation are available, NF1 remains a clinical diagnosis. Many manifestations of NF1 involve the eye and orbit, and the ophthalmologist, therefore, plays a significant role in the diagnosis and treatment of NF1 patients. Improvements in diagnostic and imaging instruments have provided new insight to study the ophthalmic manifestations of the disease. We provide a comprehensive and up-to-date overview of the ocular and orbital manifestations of NF1.

Giant phaeochromocytoma presenting with an acute stroke: reappraising phaeochromocytoma surveillance for the neurofibromatosis type 1 phakomatosis

Neurofibromatosis type 1 (NF1) is a multisystem genetic disorder associated with reduced lifespan attributed largely to malignancy and vascular causes. One of the tumours associated with NF1 is phaeochromocytoma. The phaeochromocytoma has earned the moniker, a 'great mimicker', due to its varied means of presentation. We present a patient with NF1 who was diagnosed with a giant 20 cm phaeochromocytoma after suffering from an ischaemic stroke. Current guidelines do not advocate surveillance of phaeochromocytoma in asymptomatic patients with NF1, unlike other genetic syndromes associated with phaeochromocytoma. However, there is increasing evidence that this approach may not help in the early detection and treatment of this potentially life-threatening disease. Our patient remained hypertensive after surgery despite achieving biochemical cure. The suggested chronicity of the underlying tumour in our patient is a reminder to practising clinicians to rethink our strategy in identifying phaeochromocytoma in adults with NF1.

Brief Report: The Prevalence of Neurofibromatosis Type 1 among Children with Autism Spectrum Disorder Identified by the Autism and Developmental Disabilities Monitoring Network

Neurofibromatosis type 1 (NF1) is an inherited neurocutaneous disorder associated with neurodevelopmental disorders including autism spectrum disorder (ASD). The frequency of ASD/NF1 co-occurrence has been subject to debate since the 1980s. This relationship was investigated in a large population-based sample of 8-year-old children identified with ASD (N = 12,271) by the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring (ADDM) Network. Twenty-two (1-in-558) children with ASD had diagnosed NF1, exceeding NF1 general population estimates by four to five fold. Children with ASD/NF1 versus ASD without NF1 were significantly less likely to receive a community-based ASD diagnosis (p = 0.04) and understand non-verbal communication (p = 0.001). These findings underscore the importance of including social-communication ability among relevant developmental concerns in children with NF1.

A novel approach in pediatric telegenetic services: geneticist, pediatrician and genetic counselor team

Purpose

Our aim was to improve access to genetic services in an underserved region by developing a collaborative telegenetic service delivery model with a pediatrician, medical geneticist, and genetics counselor (GC).

Methods

Protocols for the evaluation of common genetic indications were developed. Patients referred with indications suggestive of a syndromic etiology were scheduled to see the geneticist directly via telegenetics. Other patients were scheduled to see the pediatrician and GC in person before follow-up with the geneticist if indicated. Patients seen by the geneticist and/or pediatrician/GC were enumerated and the next available appointment was tracked. Patient satisfaction surveys were conducted.

Results

Of the 265 patients evaluated during the study period, 116 (44%) were evaluated by a pediatrician and GC in person first, after which 82 (71% of those evaluated) required further follow-up with the geneticist. The next available appointment with a pediatrician and GC never exceeded 6 weeks, while new appointments with a geneticist ranged from 3 to 9 months. All patients reported high satisfaction with this genetic service model.

Conclusion

The pediatrician/GC clinic provides a model of collaborative care that is a medical home neighbor and exemplifies the integration of genetics into primary care. The telegenetics clinic offers a viable solution to providing competent and convenient access to a geneticist for patients in chronically underserved regions.

Pheochromocytomas are diagnosed incidentally and at older age in neurofibromatosis type 1

INTRODUCTION

Guidelines do not currently recommend routine systematic hormonal screening for pheochromocytoma (PHEO) in all/normotensive patients with neurofibromatosis type 1 (NF1), in contrast to other PHEO-predisposing genetic syndromes such as Von Hippel-Lindau syndrome and multiple endocrine neoplasia type 2.

OBJECTIVES

To characterize and compare parameters of PHEO in patients with NF1 to patients with or without other germline mutations.

METHODS

A retrospective chart review of patients with histologically proven PHEO at the Centre hospitalier de l'Université de Montréal from 2000 through 2015.

RESULTS

Neurofibromatosis type 1 was diagnosed clinically in nine patients in our cohort of 145 PHEO (6·2%). The mean age at diagnosis was 48 ± 14 years, and seven patients had hypertension. No PHEO was diagnosed by systematic clinical screening. The mode of presentation was adrenal incidentalomas in five patients. Urinary metanephrines were elevated in 5/9 cases. Mean tumour diameter was 3·5 cm (min-max 1·5-12·5 cm). One had bilateral PHEO and none were malignant to date. Statistically significant differences were noted when comparing PHEO in NF1 to other genetic syndromes (n = 20), in terms of age at diagnosis (mean 48 vs 30 years P < 0·05), initial mode of presentation (no PHEO detected by routine screening in NF1 vs 40% in other genetic syndromes P < 0·05) and familial history of catecholamine-secreting tumour (none in NF1 vs 55% in patients with other genetic syndrome P < 0·05).

CONCLUSIONS

Pheochromocytoma in NF1 occurs in older patients with no family history compared to other syndromes; it is mostly unilateral, secretory and benign. The older age at diagnosis of PHEO could be secondary to delay in identification due to lack of systematic screening for PHEO in NF1.

Neurocutaneous Disorders in Children

Neurofibromatosis (NF), including type 1 (NF1), type 2 (NF2), and schwannomatosis; tuberous sclerosis complex (TSC); and Sturge-Weber syndrome are 3 neurocutaneous disorders that typically present in childhood. Early recognition by the pediatrician can be critical to surveillance for treatable complications and genetic counseling. These conditions are diagnosed clinically, but genetic testing is available to clarify an uncertain diagnosis or help with genetic counseling. Although many of the complications can only be treated symptomatically, advances in understanding of the pathogenesis are opening new approaches to molecularly targeted therapeutics, which promise to alter the natural history of the conditions in the years to come.