Presenting symptoms in children with neurofibromatosis type 2

Classification of schwannomas and the new naming convention for "neurofibromatosis-2": Genetic updates and international consensus recommendation

Despite their similar nomenclature, Neurofibromatosis type 1 (NF1) and "Neurofibromatosis type 2" are discrete and clinically distinguishable entities. The name of "neurofibromatosis type 2" has been changed to NF2-related schwannomatosis, to reflect the fact that neurofibromas do not occur in this syndrome and therefore the name "Neurofibromatosis" is factually incorrect. Furthermore, multiple schwannomas, a hallmark feature of NF2, can also occur in patients with mutations in genes including SMARCB1 and LZTR1, all exhibiting overlapping clinical features. Current understanding suggests that schwannomatosis (SWN) encompasses a range of clinical presentations consisting of clearly defined, separate subtypes which share a common phenotype of schwannomas. Recognizing these newly emerging subtypes, the International Consensus Group on Neurofibromatosis Diagnostic Criteria (I-NF-DC) proposed a revised nomenclature for NF2 and related disorders in 2022. This review article focuses on this critical update in diagnostic terminology, highlighting the key gene-related SWN subtypes relevant to neuroradiologists. By emphasizing molecular testing alongside clinical features, the revised system facilitates a more precise diagnosis, potentially paving the way for personalized treatment strategies. Additionally, the flexible structure accommodates future discoveries of genes associated with SWN.

Death in a bathtub of an adolescent with neurofibromatosis type 2 exhibiting meningioangiomatosis with white matter involvement

Neurofibromatosis type 2 (NF2) is a neurocutaneous syndrome characterized by the development of multiple benign tumors, including vestibular schwannomas and meningiomas, in the nervous system. Seizures are rarely associated with NF2, and the lethality of this condition typically stems from tumor growth and related complications, leaving the incidence of sudden death largely unreported. This report discribes a 16-year-old girl with a history of NF2 and occasional seizures who died unexpectedly in a bathtub. Postmortem examination revealed multiple tumors in the cranial nerves (schwannoma), under the dura mater (meningioma), and in the upper cervical cord (neurofibroma). Typical signs of drowning, such as foam in the airways, were not present. Upon histological examination, meningioangiomatosis (MA) was observed in the cerebellum and the cerebral cortex, specifically in the frontal lobe, temporal lobe, and insula. The MA extended into the white matter, exhibiting severe perivascular fibrosis and cystic dilatation of perivascular spaces in the frontal lobe and cerebellum. Additionally, glial microhamartomas were detected both around and separate from the MA. These autopsy findings suggest that sudden unexpected death in epilepsy (SUDEP) was the cause of death rather than drowning. Moreover, while NF2-associated MA is typically asymptomatic, unlike sporadic MA, which commonly presents with seizures, the spread of MA into the white matter is unusual in an NF2 patient. Therefore, MA with the white matter involvement could have been a factor causing the seizures and the occurrence of SUDEP in this NF2 patient.

Spectrum of cutaneous lesions in a cohort of patients with neurofibromatosis type 2

BACKGROUND

Neurofibromatosis type 2 (NF2) is a rare autosomal dominant syndrome with a predisposition to the development of central nervous system tumors, ophthalmic manifestations, and dermatological lesions. The latter are present in 70-95% of patients and can precede the evolution of other tumors. However, they are not included in the diagnostic criteria and are frequently undervalued during follow-up.

METHODS

An observational cross-sectional study characterizing cutaneous lesions in a cohort of NF2 patients was carried out. Dermatological examinations were performed, and lesions were classified into neural cutaneous tumors (superficial, SNCT, and deep, DNCT), hyperpigmented patches (HyperP), and hypopigmented patches (HypoP). The Dermatology Life Quality Index (DLQI) and EQ-5D questionnaires were applied to evaluate the impact on quality of life.

RESULTS

Nineteen patients with a mean age of 36 years were included. Sixteen (84%) patients had cutaneous lesions, mostly developed 10 or more years before the diagnosis. SNCT, DNCT, and HyperP showed similar frequencies (58%). HypoP were observed in only one patient. HyperP developed, on average, earlier than NCT (9.6 vs. 16.5 SNCT, 17.0 DNCT; years). The excised lesions had different histological patterns, including neurofibromas, schwannomas, and a hybrid tumor. Most patients reported a low impact of cutaneous manifestations on the quality of life (DLQI 0 or 1).

CONCLUSIONS

Cutaneous lesions are frequent in NF2 and may precede the diagnosis by several years. Their identification is important to establish the diagnosis earlier and potentially reduce morbidity and mortality.

Neurofibromatosis Type-2 presenting with vision impairment

Neurofibromatosis Type-2 (NF2) is an autosomal dominant genetic tumour-predisposing condition caused by mutations in the NF2 gene located on chromosome 22q12. It is characterized by multiple benign tumours of the central and peripheral nervous systems and meninges, causing high morbidity. Herein, presentation of a rare case of NF2 in a 36-year-old female who presented with right eye visual disturbances, followed by tinnitus with hearing impairment. The visual disturbance developed into blindness. Magnetic resonance imaging (MRI) was performed, which showed a right-side cerebellopontine angle vestibular schwannoma and multiple meningiomas around the brain. According to the MRI findings, the patient was diagnosed with NF2. This case report aims to elucidate the importance of early brain imaging in any visual disturbances in young adults and to highlight the key role of medical imaging in the diagnosis of rare cases. Moreover, this describe the MRI features and the diagnostic accuracy for the tumours occurring in NF2 in detail.

A review of bilateral sudden sensorineural hearing loss in pediatric patients

OBJECTIVE

Bilateral, sudden sensorineural hearing loss (SSNHL) in the pediatric population is a rare phenomenon potentially detrimental to language acquisition and social development. This study comprehensively reviews and analyzes existing literature to determine any correlation or commonality in etiologies, presentations, and management of this condition.

METHODS

PubMed, Cochrane, Scopus, and Web of Science databases were systematically searched for articles related to pediatric SSNHL from 1970 to 2021. Case series, case reports, and cohort studies were included. Data on patient demographics, etiology, diagnostic testing, management, and hearing recovery were collected.

RESULTS

Excluding duplicates, 553 unique titles were identified by established search criteria, of which 342 titles were relevant to pediatric sudden hearing loss. Forty-six papers reported cases of bilateral SSNHL, totaling 145 individual cases. Not included in the analysis were 45 cases documented as non-organic hearing loss. The average age of the total 145 included patients was 8.5 years and 51 were male. Reported etiologies included cytomegalovirus (n = 3), meningitis (n = 13), mumps (n = 5), ototoxin exposure (n = 13), and enlarged vestibular aqueduct (n = 9). Tinnitus (n = 30) was the most reported concurrent symptom, followed by vertigo (n = 21). Systemic steroid therapy was the most common treatment and, when follow up was reported, most patients (51.2%) had complete or partial recovery of hearing.

CONCLUSIONS

This is a comprehensive review of pediatric bilateral SSNHL. Though often idiopathic, etiologies also include infectious, structural, and autoimmune. Treatment largely consists of systemic steroid therapy, with variables rates of recovery. Further studies on intratympanic administration of steroids may guide future treatment.

[New classification and approaches to the treatment of schwannomatosis]

Schwannomatoses is a new classification unit for all the hereditary diseases caused by chromosome 22 damage followed by multiple benign neoplasms of the peripheral and central nervous system. Schwannomatosis occurs as a result of damage to different genes: NF2, SMARCB1, LZRT1, loss of heterozygosity of the long arm of chromosome 22. Nevertheless, clinical manifestations are similar. Molecular diagnostics not only confirms the diagnosis, but also predicts the course of disease. Thus, the most severe clinical manifestations are observed in patients with violation of semantic sequences and reading frame shift in exons 2-13 of the NF2 gene. A more favorable course with less number of tumors is observed in patients with somatic mosaicism. Stereotactic irradiation and surgery are the main treatment options for schwannomatosis. However, there is evidence of effective targeted therapy with bevacizumab (inhibitor of vascular endothelial growth factor). Bevacizumab is used in patients with bilateral vestibular schwannomas and high risk of hearing loss, as well as for intramedullary tumor growth control.

Management of neurofibromatosis type 2 and schwannomatosis associated peripheral and intraspinal schwannomas: influence of surgery, genetics, and localization

Introduction

Peripheral and intraspinal schwannomas are common and clinically complex pathologies in patients with Neurofibromatosis Type 2 (NF2) and Schwannomatosis (SWNT). Functional preservation and pain relief are the major goals in treating these tumors.

Methods

This retrospective observational study investigates the clinical and functional outcome of 205 operated peripheral (n = 148, 72%) and intraspinal (n = 57, 28%) schwannomas in 85 patients (53 NF2, 32 SWNT) treated at our department between 2006 and 2017. Associated factors such as genetics, age, and location were evaluated.

Results

Persisting drug-resistant pain was the most common symptom (84%, n = 173) and indication for surgery (54%, n = 110). Improvement in pain intensity was postoperatively seen in 81%. Peripheral nerve schwannomas exhibited worse pain intensity preoperatively compared to intraspinal lesions (p = 0.017 NF2, p = 0.029 SWNT). More total resections could be achieved in 93% of SWNT vs. 82% of NF2-associated tumors, p = 0.030). NF2 patients with intraspinal lesions were more neurologically affected (p < 0.05). Perioperative comparison of both tumor syndromes showed more neurological deficits (p = 0.027), and less pain (p = 0.024) in NF2-associated tumors. Mosaic NF2 patients had worse pain levels before surgery, and SWNT patients had a worse neurological function and more pain compared to non-mosaic or non-mutated cases.

Conclusions

Resection of peripheral and intraspinal schwannomas is an effective and low-risk treatment in both NF2 and SWNT. Patients with severe pain have a particular benefit from surgical treatment. Intraspinal lesions are associated with worse neurological function whereas peripheral lesions showed a higher pain intensity. The influence of mutations needs to be further investigated in larger cohorts.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-022-04061-0.

Dermatologic manifestations in paediatric neurofibromatosis type 2: a cross sectional descriptive multicentric study

Background

Neurofibromatosis type 2 (NF2) is characterized by bilateral vestibular schwannoma (VS) more often in adults but a severe paediatric form with multiple neurological tumours is also described. In this population, a early diagnosis is important to prevent the onset of neurological complications but is difficult, particularly without a familial history. Cutaneous manifestations, which may precede VS or neurological tumours by several years, may contribute to an early diagnosis, but specific studies are lacking. The objective of this study was to characterize cutaneous manifestations of NF2 in a paediatric population.

Results

This observational, descriptive and multicentric study was conducted from April 2019 to April 2020 in seven academic French hospitals. We included patients ≤ 18 years old who fulfilled the Manchester diagnostic criteria or had a pathogenic mutation identified in the NF2 gene. All patients underwent a dermatological examination guided by a standardized questionnaire. 21 children were included, of whom 20 had at least one skin tumour (mean number 5 ± 4.6 [range 0–15]), which led to a diagnosis in four cases. In the other 17 cases, the diagnosis of NF2 was based on neurosensory complications (n = 10), family screening (n = 4) or ocular signs (n = 3). Before the NF2 diagnosis, 15 children had at least one “undiagnosed” cutaneous tumour that did not lead to a specific management. Patients’ dermatological examination also revealed < 6 non specific café au lait macules (n = 15), hypopigmented macules (n = 12) with more than 3 lesions in 4 cases, and purple reticulated macules of the trunk (n = 4).

Conclusion

Dermatological lesions are frequent and early in children with NF2 but rarely lead to the diagnosis. Cutaneous schwannomas are the most frequent but are often underdiagnosed. Café au lait macules are frequent, but atypical and mostly in small numbers. Multiple hypopigmented macules seem suggestive although inconsistent. The sensitivity of reticulated capillary malformation-like lesions remains to be assessed by further studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02379-6.

Management of Sporadic Vestibular Schwannomas in Children—Volumetric Analysis and Clinical Outcome Assessment

Vestibular schwannomas (VS) usually manifest between the 5th and 8th decade of life. Most pediatric cases are associated with Neurofibromatosis type 2 and sporadic VS are rare in this age group. Few case series have been published. We report on our institutional series of sporadic VS in children. We included all cases between 2003 and 2021; 28 of 1635 patients harbored a sporadic VS and were younger than 21 years old. A retrospective review of clinical parameters and surgical data as well as outcomes was performed. All procedures were performed via a retrosigmoid approach. Preoperative imaging was assessed, and tumor volumetry was performed. Mean follow-up was 28 months, symptomatology was diverse. Most children and adolescents presented with hearing loss and tinnitus. All cases with multiple preoperative magnetic resonance imaging scans showed volumetric tumor growth between 1 and 18%/month (mean 8.9 ± 5.6%). Cystic tumor morphology and bone erosion was seen in larger tumors. Gross total resection was possible in 78% of patients and no recurrence was observed. All patients with subtotal resection showed tumor regrowth. Sporadic VS in children are rare and present with a high clinical variability. Surgical resection is the primary therapy and is feasible with favorable results comparable to the adult age group.

Risk Stratification for Immediate Postoperative Hearing Loss by Preoperative BAER (Brainstem Auditory Evoked Response) and Audiometry in NF2-Associated Vestibular Schwannomas

Simple Summary

Hearing preservation is one of the major goals in the surgical treatment of Neurofibromatosis Type 2 (NF2) associated vestibular schwannomas (VS) and hearing diagnostics are important monitoring parameters and intraoperative tools to pursue this goal. Our monocentric retrospective analysis aimed to predict postoperative hearing deterioration or loss based on preoperative audiometry and neurophysiological (brainstem auditory evoked potentials, BAEP) findings. In this respect and according to our data evaluation in 100 NF2-associated VS of 72 patients both parameters seem to be prognostic markers, particularly BAEP findings. Large discrepancies between both audiometry and BAEPs which were identified in twenty-one cases of our cohort appear to be at high risk of significant postoperative hearing worsening.

Abstract

Both brainstem auditory evoked potentials (BAEP) and audiometry play a crucial role in neuro-oncological treatment decisions in Neurofibromatosis Type 2 associated (NF2) vestibular schwannoma (VS) as hearing preservation is the major goal. In this study, we investigated the risk of immediate postoperative hearing deterioration (>15 dB and/or 15% loss in pure-tone average [PTA]/ speech discrimination score [SDS] in a cohort of 100 operated VS (ears) in 72 NF2 patients by retrospective analysis of pre- and postoperative hearing data (PTA, SDS, American Association of Otolaryngology–Head and Neck Surgery [AAO-HNS], and brainstem auditory evoked potential [BAEP] class) taking into account relevant influencing factors, particularly preoperative audiometry and BAEP status and the extent of resection. Immediately after surgery, the hearing was preserved in 73% of ears and approximately ~60% of ears kept their hearing classes. Preoperative BAEP (p = 0.015) and resection amount (p = 0.048) significantly influenced postoperative hearing outcome. The prediction model for postoperative hearing deterioration/loss between preoperative BAEP and AAO-HNS class showed increased risk by increasing BAEP class. Twenty-one tumors/ears were identified with large BAEP and AAO-HNS class discrepancies (≥2 points) and were associated with a high (48–100%) risk of deafness after surgery in ears with preoperative available hearing. Overall, the results were heterogeneous but the better both BAEP and audiometry class before surgery, the higher the chance of hearing maintenance afterwards. Large resection amounts (e.g., 100% risk in near-total resections) exhibit a significant (p < 0.05) higher risk compared to smaller amounts (e.g., 10/20% in laser-coagulated/partially resected tumors). Our results emphasized the indispensable role of both hearing monitoring in form of audiometry and neurophysiology (BAEP) in the pre-and perioperative monitoring of NF2-associated VS. Both BAEP and audiometry are good prognostic markers for the postoperative hearing outcome. The extent of resection should be strictly guided by and adjusted to the intraoperative neurophysiological monitoring.

Age at Onset and Presenting Symptoms of Neurofibromatosis Type 2 as Prognostic Factors for Clinical Course of Vestibular Schwannomas

The presenting symptoms of the tumor suppressor gene syndrome neurofibromatosis type 2 (NF2) are often non-specific and unrelated to the disease hallmark bilateral vestibular schwannomas (VS). However, age at onset and presenting symptoms may have predictive values for the clinical course of VS. In this retrospective single-center study, we addressed this issue by reviewing 106 patients with 194 VS. Presenting symptoms attributable to VS commonly occur in 87% of adults and 31% of children. Age at onset significantly correlates with tumor volumes at presentation (p = 0.034). In addition, age at onset significantly correlates with pure-tone average (p = 0.0001), speech discrimination scores (p = 0.001), age at beginning of hearing loss (p = 0.0001), age at deafness (p = 0.0001), and age at first surgery (p = 0.0001). Patients presenting with VS related symptoms had significantly (p < 0.05) worse hearing values at presentation and after surgery. These patients also exhibited higher growth rates and tumor volumes compared to patients with non-VS related presenting symptoms, but this difference did not reach the significance level of p < 0.05. Due to the late appearance of these symptoms, the time of beginning hearing loss, surgery and deafness is significantly delayed (p < 0.05) compared to patients not presenting with VS. In summary, age at onset and type of presenting symptom provide excellent prognostic parameters for predicting VS- and hearing-related clinical course.