Neurofibromatosis 1 in childhood

Early Detection of Malignant and Premalignant Peripheral Nerve Tumors Using Cell-Free DNA Fragmentomics

PURPOSE

Early detection of neurofibromatosis type 1 (NF1)-associated peripheral nerve sheath tumors (PNST) informs clinical decision-making, enabling early definitive treatment and potentially averting deadly outcomes. In this study, we describe a cell-free DNA (cfDNA) fragmentomic approach that distinguishes nonmalignant, premalignant, and malignant forms of PNST in the cancer predisposition syndrome, NF1.

EXPERIMENTAL DESIGN

cfDNA was isolated from plasma samples of a novel cohort of 101 patients with NF1 and 21 healthy controls and underwent whole-genome sequencing. We investigated diagnosis-specific signatures of copy-number alterations with in silico size selection as well as fragment profiles. Fragmentomics were analyzed using complementary feature types: bin-wise fragment size ratios, end motifs, and fragment non-negative matrix factorization signatures.

RESULTS

The novel cohort of patients with NF1 validated that our previous cfDNA copy-number alteration-based approach identifies malignant PNST (MPNST) but cannot distinguish between benign and premalignant states. Fragmentomic methods were able to differentiate premalignant states including atypical neurofibromas (AN). Fragmentomics also adjudicated AN cases suspicious for MPNST, correctly diagnosing samples noninvasively, which could have informed clinical management.

CONCLUSIONS

Novel cfDNA fragmentomic signatures distinguish AN from benign plexiform neurofibromas and MPNST, enabling more precise clinical diagnosis and management. This study pioneers the early detection of malignant and premalignant PNST in NF1 and provides a blueprint for decentralizing noninvasive cancer surveillance in hereditary cancer predisposition syndromes.

Preliteracy impairments in children with neurofibromatosis type 1

AIM

This cross-sectional study aimed to examine the preliteracy abilities of young children with neurofibromatosis type 1 (NF1) and to identify which of these abilities best predicted conventional literacy (spelling).

METHOD

Forty-two children with NF1 (23 males, 19 females; mean age [SD] 5y 6mo [6mo]) were compared with 32 unaffected children (15 males, 17 females; mean age [SD] 5y 4mo [6mo]). All children completed a comprehensive cognitive assessment including measures of phonological processing (phonological awareness, phonological memory, rapid automatic naming) and letter-sound knowledge.

RESULTS

Children with NF1 performed significantly poorer than the comparison group across all cognitive and preliteracy domains, with specific weaknesses evident in phonological awareness (F_1,68 =14.13, p<0.001, partial η² =0.17), phonological memory (F_1,68 =13.87, p<0.001, partial η² =0.17), and letter-sound knowledge (F_1,71 =5.65, p=0.020, partial η² =0.07). Within the group with NF1 group, over a third of children demonstrated impairment in at least one phonological processing domain and the risk of phonological impairment was 5.60 times that of unaffected children. Children's letter-sound knowledge was the strongest predictor of conventional literacy (spelling).

INTERPRETATION

This study establishes that preliteracy deficits are present and detectable in young children with NF1. As a result of the high incidence of preliteracy impairment, we recommend screening phonological awareness and letter-sound knowledge to identify risk of future learning disorders.

WHAT THIS PAPER ADDS

Young children with neurofibromatosis type 1 are at elevated risk of preliteracy deficits. The most affected domains are phonological awareness and phonological memory. Letter-sound knowledge is the strongest predictor of conventional literacy (spelling).

Epilepsy in neurofibromatosis type 1

OBJECTIVES

To describe the characteristics of epilepsy in patients with Neurofibromatosis type 1 (NF1).

METHODS

Analysis of a cohort of consecutive NF1 patients seen in our NF1 clinic during a three-year period.

RESULTS

Of the 184 NF1 patients seen during that period, 26 had epilepsy and three had febrile seizures. Of the 26, 17 (65%) had localization-related epilepsy, seven of whom (41%) were drug resistant. Six (23%) had apparently primary generalized epilepsy (0/6 drug resistant), two (8%) Lennox-Gastaut syndrome, and one (4%) West syndrome (all three were drug-resistant). As compared to the patients with no epilepsy, those with epilepsy were more likely to have MRI findings of mesial temporal sclerosis (MTS) (23% vs. 5%, p=0.0064), and cerebral hemisphere tumors (31% vs. 10%, p=0.0079), but not of the other MRI findings including neurofibromatosis bright objects, or optic gliomas. Three of the six patients with MTS underwent temporal lobectomy with subsequent control of their seizures with confirmation of MTS on pathology in 3/3 and presence of coexisting focal cortical dysplasia (FCD) in 2/3. We also have observed three additional patients outside the above study with the association of NF1, MTS, and intractable epilepsy.

SIGNIFICANCE

Epilepsy is relatively common in NF1, often occurs in patients with brain tumors or with MTS which can coexist with FCD, can be associated with multiple types of epilepsy syndromes, and when localization-related is often drug-resistant. Patients with NF1 and MTS can respond to medial temporal lobectomy and may have coexisting medial temporal lobe cortical dysplasia.

The use of electrodessication in the treatment of cutaneous neurofibromatosis: A retrospective patient satisfaction outcome assessment

INTRODUCTION

Neurofibromatosis I (NF-1) is an autosomal dominant disease giving rise to hundreds of cutaneous neurofibromas. In addition to localised symptoms such as pain and pruritus, these lesions can have a devastating psychosocial impact. To date, there is no consensus on the optimal management of these lesions. We present the clinical and patient-reported outcomes of a series of NF-1 patients treated with electrodessication by one surgeon.

METHODS

All patients treated by electrodessication for cutaneous neurofibromas between 2012 and 2015 by one clinician were retrospectively reviewed. Clinical and patient-reported outcomes were measured using a patient satisfaction questionnaire and review of the notes.

RESULTS

Six patients were operated on during the study period (five women and one man). Prior to this new technique, patients had on average eight episodes (range 4-20) of excisional procedures under local anaesthesia removing one to five lesions. With electrodessication, patients had on average three (range 1-5) electrodessication episodes under general anaesthesia, treating hundreds of lesions per session. All patients were treated as a day case. One patient experienced a minor wound infection and another minor bleeding. Five of six patients preferred electrodessication to surgical excision.

CONCLUSION

Electrodessication enables the treatment of hundreds of neurofibromas in a single operation. The procedure has low complication rates with high levels of clinical and patient-reported outcomes.

Massive Plexiform Neurofibroma of the Neck and Larynx

Introduction Laryngeal neurofibromas are extremely rare, accounting for only 0.03 to 0.1% of benign tumors of the larynx.

Objectives To report the first case of massive neck plexiform neurofibroma with intralaryngeal (supraglottic) extension in a 5-year-old boy with neurofibromatosis type 1 and to describe its treatment.

Resumed Report This massive plexiform neurofibroma was surgically removed, relieving its significant respiratory obstructive symptoms without recurrence to date.

Conclusion Massive neck plexiform neurofibroma with supraglottic part was found in a child with neurofibromatosis type 1; it should be included in differential diagnosis of stridor and neck mass in children. It was diagnosed and removed in early in childhood without recurrence.

Adaptive behavior in young children with neurofibromatosis type 1

Neurofibromatosis-1 is the most common single gene disorder affecting 1 in 3000. In children, it is associated not only with physical features but also with attention and learning problems. Research has identified a downward shift in intellectual functioning as well, but to date, there are no published studies about the everyday adaptive behavior of children with NF1. In this study, parental reports of adaptive behavior of 61 children with NF1 ages 3 through 8 were compared to an unaffected contrast group (n = 55) that comprised siblings and community members. Significant group differences in adaptive skills were evident and were largely related to group differences in intellectual functioning. In a subsample of children with average-range intellectual functioning, group differences in parent-reported motor skills were apparent even after controlling statistically for group differences in intellectual functioning. The implications of the findings for the care of children with NF1 are discussed.

Development of the adult PedsQL™ neurofibromatosis type 1 module: initial feasibility, reliability and validity

BACKGROUND

Neurofibromatosis type 1 (NF1) is a common autosomal dominant genetic disorder with significant impact on health-related quality of life (HRQOL). Research in understanding the pathogenetic mechanisms of neurofibroma development has led to the use of new clinical trials for the treatment of NF1. One of the most important outcomes of a trial is improvement in quality of life, however, no condition specific HRQOL instrument for NF1 exists. The objective of this study was to develop an NF1 HRQOL instrument as a module of PedsQL™ and to test for its initial feasibility, internal consistency reliability and validity in adults with NF1.

METHODS

The NF1 specific HRQOL instrument was developed using a standard method of PedsQL™ module development - literature review, focus group/semi-structured interviews, cognitive interviews and experts' review of initial draft, pilot testing and field testing. Field testing involved 134 adults with NF1. Feasibility was measured by the percentage of missing responses, internal consistency reliability was measured with Cronbach's alpha and validity was measured by the known-groups method.

RESULTS

Feasibility, measured by the percentage of missing responses was 4.8% for all subscales on the adult version of the NF1-specific instrument. Internal consistency reliability for the Total Score (alpha =0.97) and subscale reliabilities ranging from 0.72 to 0.96 were acceptable for group comparisons. The PedsQL™ NF1 module distinguished between NF1 adults with excellent to very good, good, and fair to poor health status.

CONCLUSIONS

The results demonstrate the initial feasibility, reliability and validity of the PedsQL™ NF1 module in adult patients. The PedsQL™ NF1 Module can be used to understand the multidimensional nature of NF1 on the HRQOL patients with this disorder.

Neurogenic tumors of soft tissue

Neurogenic tumors are an uncommon yet important category of soft tissue tumors in children and adolescents because of their frequent association with various genetic syndromes. The heterogeneous cellular composition of the peripheral nerve and the wide metaplastic capacity of the neural crest and its derivatives generate a variety of neoplasms with neurogenic differentiation. This article reviews the clinicopathologic features and differential diagnosis of neurogenic tumors in the first two decades of life, and highlights use of selected ancillary methods for diagnosis.

Intracerebral malignant peripheral nerve sheath tumor in a child with neurofibromatosis Type 1 and middle cerebral artery aneurysm treated with endovascular coil embolization

Among the neoplastic conditions that affect patients with neurofibromatosis Type 1 (NF1) are malignant peripheral nerve sheath tumors (MPNSTs), which typically arise from peripheral nerves of the limbs, trunk, and lumbar and brachial plexuses. Ionizing radiation is an established risk factor for MPNST development, especially in susceptible patients such as those with NF1. Patients with NF1 are also at risk for intracranial aneurysms, which are increasingly being successfully managed with endovascular therapies. The authors describe the case of a 9-year-old, previously healthy girl who presented in extremis with a right frontal intracerebral hemorrhage resulting from a ruptured right middle cerebral artery (MCA) trifurcation aneurysm. Following urgent decompressive craniectomy, the patient underwent endovascular coil embolization of the MCA aneurysm without complication. Given her mother's history of NF1, the child underwent genetic testing, which disclosed signs positive for NF1. The patient recovered well, but follow-up MR imaging and MR angiography performed at 14 months demonstrated a large frontotemporal mass encasing the right MCA trifurcation. The patient underwent frontotemporal craniotomy and subtotal resection of the mass, which was histologically found to be an intracranial MPNST. The patient received chemotherapy and focal radiation therapy and remains alive at 6 months postresection. To the authors' knowledge, this represents the only known case of intracranial neoplasm arising in the region of an intracranial aneurysm repaired by endovascular coil embolization. While patients with NF1 represent a population with genetic susceptibility to radiation-induced tumors, the pathogenesis of intracerebral MPNSTs remains poorly understood.

The cognitive profile of preschool-aged children with neurofibromatosis type 1

Few studies have examined the cognitive profile of young children with NF1. In this study, 26 children with NF1 (M(age) = 5 years 3 months) were compared with 21 peer comparisons (M(age) = 4 years 8 months) and available normative data on neuropsychological measures. Children with NF1 demonstrated the characteristic downward shift in IQ, poor visuospatial constructional skills, and inattention. Working memory deficits were common in parental ratings. These findings suggest that at least some of the cognitive deficits associated with NF1 can be identified in the preschool-age group, highlighting the need for early assessment and intervention.

Lesions of the corpus callosum in children with neurofibromatosis 1

Our aim was to determine the rate of focal lesions of the corpus callosum in children with neurofibromatosis type 1, and to characterize their natural history. Magnetic resonance imaging scans of the brain in 79 children with neurofibromatosis type 1 who were followed at the Neurology Clinic of Schneider Children's Medical Center (Petah Tiqwa, Israel) from 1990-2005 were reviewed. Focal lesions of the corpus callosum were identified in 11 (14%). These included unidentified bright objects in 7 patients (9%), and a neoplastic process in 4 (5%). Follow-up ranged from 1-16 years. Two of 4 tumors had enlarged during follow-up, and one was excised. Neurofibromatosis type 1 may be associated with a 14% prevalence of corpus callosum lesions. Owing to the apparently high frequency of callosal neoplasms in this population (5% in our series), and their tendency to enlarge, careful evaluation and prolonged follow-up are warranted.

Complex vascular reconstruction of abdominal aorta and its branches in the pediatric population

BACKGROUND

Subdiaphragmatic aortic diseases in children are rare and form a heterogeneous group. The pediatric patient presents unique challenges because of their size, concerns about proper timing and conduit for repair, and anticipating expected growth.

METHODS

We performed a retrospective review of operations involving the abdominal aorta and called branches in children between January 2003 and April 2007, focusing on the details of preoperative evaluation, operative technique, and outcomes. The pertinent literature is reviewed.

RESULTS

Twenty-two children (age, 2 days to 17 years) were included. Mean follow-up was 28 months. Aneurysms were seen in 5 children; the remainder had stenotic disease. Aneurysms were typically asymptomatic and diagnosed incidentally, whereas stenotic lesions most commonly presented with hypertension (HTN). Fourteen complex vascular repairs were performed. All of the children with aneurysms underwent prompt surgery. The children with stenoses had operations for poorly controlled HTN, claudication, and/or mesenteric ischemia. Most patients with stenotic disease were treated medically for HTN and were followed closely while awaiting optimal size and availability of autogenous conduit for reconstruction. Cryopreserved allograft was used in 3 of the aneurysm operations. Dacron grafts were used to repair 5 aortic stenotic lesions. Renal and mesenteric revascularizations were performed with saphenous vein grafts. Pediatric, general, and transplant surgeons and nephrologic and cardiologic teams were integral to evaluation and management. No major operative complications occurred.

CONCLUSION

Proper management of pediatric aortic vascular disease requires a multidisciplinary approach. It is best to use autologous grafts whenever possible. Children with stenotic disease should be treated medically for hypertension until they are large enough for an autologous graft reconstruction. Children with aneurysmal disease are at risk for embolism and thrombosis and therefore usually treated immediately using artificial graft material, if necessary.

Health supervision for children with neurofibromatosis

Neurofibromatosis 1 is a multisystem disorder that primarily involves the skin and nervous system. Its population prevalence is 1 in 3500. The condition usually is recognized in early childhood, when cutaneous manifestations are apparent. Although neurofibromatosis 1 is associated with marked clinical variability, most affected children do well from the standpoint of their growth and development. Some features of neurofibromatosis 1 are present at birth, and others are age-related abnormalities of tissue proliferation, which necessitate periodic monitoring to address ongoing health and developmental needs and to minimize the risk of serious medical complications. This clinical report provides a review of the clinical criteria needed to establish a diagnosis, the inheritance pattern of neurofibromatosis 1, its major clinical and developmental manifestations, and guidelines for monitoring and providing intervention to maximize the growth, development, and health of an affected child.

Dural arteriovenous fistula of the greater sphenoid wing region in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) has been infrequently associated with different cerebrovascular conditions that may lead to either ischemic or hemorrhagic stroke. Intracranial dural arteriovenous fistulas have not been described in NF1 patients. In this paper we present a unique case of an 8-year-old child with florid NF1 that presented a greater sphenoid wing dural arteriovenous fistula draining directly through the superior ophthalmic vein and causing exophthalmos. The fistula was cured by direct trans-superior ophthalmic vein approach, by means of detachable coils. Only a few cases of dural fistulas in the lesser sphenoidal wing region have been described in the literature but a fistula of the greater sphenoid wing has not been previously described.

The self-concept of children and adolescents with neurofibromatosis type 1

BACKGROUND

Neurofibromatosis type 1 (NF1) is a genetic disorder associated with cognitive deficits, learning problems, medical complications and cosmetic disfigurement. Despite the wide-ranging impact of NF1, very few studies have examined the psychosocial adjustment of individuals with NF1, and in particular, self-concept. The aims of this study were threefold: (i) to examine the self-concept of children and adolescents with NF1; (ii) to compare the self-concept of children with NF1 (NF1 only), children with NF1 and learning difficulties [NF1 + LA (low achievement)], and children with NF1 and attention deficit hyperactivity disorder (ADHD) (NF1 + ADHD); and (iii) to examine the academic self-concept of these three groups relative to objective criteria - academic achievement and teacher ratings of academic competence.

METHODS

Measures of self-concept, academic achievement and intelligence were administered to 49 children and 26 adolescents with NF1. Parents and teachers completed behavioural rating scales.

RESULTS

The majority of children and adolescents with NF1 reported positive global self-concept, with some exceptions on specific domains. Children and adolescents with NF1 reported significantly poorer self-concept for physical abilities. Adolescents also reported significantly poorer self-concept for mathematics and general self when compared with normative mean values. Clinical severity of NF1 was not a significant predictor of self-concept for physical appearance or physical abilities. Despite a significant difference between NF1 only, NF1 + LA and NF1 + ADHD groups on measures of academic achievement and teacher ratings of academic competence, there was no significant difference between the groups for academic domains of self-concept, or any other domain of self-concept. All three groups reported inflated academic self-perceptions relative to objective criteria.

CONCLUSION

Children and adolescents with NF1 are most likely to develop negative self-concepts about their physical and sporting abilities. Inflated academic self-perceptions are discussed in light of the positive illusory bias, which may serve as an adaptive or protective function.

[Familial clinical manifestation in patients with neuromesoectodermic defect]

We relate the association of two distinct cases of neuromesoectodermosis occurred in a family, one manifested as neurofibromatosis type 1 and the other as tuberous sclerosis. The two anomalies at cousins, caused by different genetic mutations and transmitted by autosomal dominant inheritance, suggest a possible relation between them. Also, clinical manifestations are described, their consequences and the diagnostic criteria of both illnesses, emphasizing the importance of the precocious diagnosis.

Cochlear implantation in a patient with neurofibromatosis type 1 and profound hearing loss: evidence to support a cochlear site of lesion

OBJECTIVE

To determine the efficacy of cochlear implantation in an individual with neurofibromatosis type 1 and profound hearing loss and to determine, to the extent possible in a living subject, the site of lesion of the hearing loss in an individual with neurofibromatosis type 1.

STUDY DESIGN

Postoperative assessment of an adult male with neurofibromatosis type 1.

SETTING

The study was completed in the Departments of Otolaryngology and Audiology, University of Massachusetts Medical Center, Massachusetts.

PATIENTS

One adult male with neurofibromatosis type 1 and bilateral, chiefly profound, sensorineural hearing loss.

INTERVENTIONS

The subject underwent cochlear implantation as treatment of bilateral, chiefly profound sensorineural hearing loss.

MAIN OUTCOME MEASURES

Outcome measures include results of electrical auditory brainstem response testing, electrical compound action potential measures, and speech recognition scores.

RESULTS

Results of testing revealed expected latencies of waves II, III, and V of the electrical auditory brainstem response, measurable compound action potentials across virtually the entire length of the electrode array, and high levels of open-set, auditory-only speech understanding.

CONCLUSIONS

This is the first case report describing the outcome of cochlear implantation in a patient with neurofibromatosis type 1. Composite test results support the absence of VIIIth nerve degeneration or other anomalies, indicating a cochlear site of lesion for the hearing loss in this patient. Based on the results of this investigation, standard cochlear implantation should be considered a viable option and the first line of therapy for the treatment of bilateral, severe to profound sensorineural hearing loss in patients with neurofibromatosis type 1 and normal, VIIIth nerve radiographic findings.

Epilepsy in neurofibromatosis 1

Neurofibromatosis 1 is the most common neurocutaneous disease. Neurologic manifestations are mainly represented by tumors such as optic gliomas, focal areas of high T2-weighted signal known as unidentified bright objects, and mental retardation or learning disabilities. The prevalence of seizures has been reported to range from 3.8 to 6%. In the present study, we evaluated prevalence, type, and etiology of epilepsy in a neurofibromatosis 1 population. A retrospective analysis of 198 patients affected by neurofibromatosis 1 was performed. Fourteen patients (7%) were found to be epileptic. Every patient underwent electroencephalographic examination and neuroimaging investigations. Thirteen were submitted to magnetic resonance imaging (MRI) study and one to computed tomographic (CT) scanning. Single-photon emission computed tomographic and positron emission tomographic studies were performed in a few selected cases. Seizures were partial in 12 of these (85%) and generalized in 2 (15%). In nine (64%), epilepsy was secondary to brain lesions: five of these had cerebral tumors (three with epilepsy as the fist symptom), three had cortical malformation, and one had mesial temporal sclerosis. Seizures were controlled rapidly in eight (57%) and drug resistant in four (29%). Two patients were lost at follow-up. All patients with uncontrolled seizures had severe mental retardation, and three of these had malformations of cortical development. Our observations and our re-evaluation of the literature indicate that patients with neurofibromatosis 1 have an increased risk of epilepsy related to intracranial masses and cytoarchitectural abnormalities, and seizures can represent the first symptom of a tumor or cortical malformation. Brain MRI and, in selected cases, functional studies appear to be useful in patients with neurofibromatosis 1 who present with seizures, especially if associated with mental retardation.

Neurocognitive dysfunction in children with neurofibromatosis type 1

The cognitive dysfunction associated with neurofibromatosis type 1 (NF1) is an intriguing aspect of this phenotypically heterogeneous genetic neurocutaneous disorder. A broad range of both nonverbal and verbal learning disabilities are evident in approximately 30% to 65% of children with NF1. Deficits in IQ, executive function, attention, and motor skills have also been documented. Current challenges lie in discovering the underlying multifactorial etiologies of the cognitive abnormalities found in NF1. Likely answers lie in neuroanatomic correlates as seen on neuroimaging as well as in molecular and genetic advances into the role of neurofibromin, the protein product of the NF1 gene. The development of NF1 animal models with learning and memory difficulties similar to those seen in humans demonstrates promising preliminary evidence that medical treatment of cognitive abnormalities may one day be possible.

Neurofibromas in children with neurofibromatosis 1

Neurofibromatosis 1 is a common autosomal dominant disease reported in approximately 1 in 3000 individuals. Although some features of neurofibromatosis 1, such as café-au-lait spots and Lisch nodules, are clinically silent, neurofibromas cause a significant degree of morbidity, mortality, and cosmetic disfigurement. Childhood through early adulthood is a vulnerable period for the growth of these lesions. Neurofibromas are a heterogeneous group of benign tumors that grow from intraneural and extraneural tissues. These tumors take on different morphology, grow at variable rates, and occur in multiple locations. Symptoms arise as neurofibromas enlarge, compressing and distorting local structures. The unpredictable nature of neurofibromas has a serious impact on the quality of life of patients with neurofibromatosis 1, and their management is challenging for physicians. Surgical removal remains the mainstay of treatment. However, advances in the understanding of the genetics and pathogenesis of neurofibromatosis 1 have led to the development of promising new biologically directed therapies. The purpose of this review is to summarize the defining characteristics, incidence, clinical course, management options, and outcome of neurofibromas in children with neurofibromatosis 1.