An algorithmic approach to the management of peripheral nerve tumours.

This article reviews the pathology and management of peripheral nerve tumours, including a framework for investigation and decision-making. Most tumours are benign, including schwannomas and neurofibromas, but malignant peripheral nerve sheath tumours can occur. The risk of malignant change is remote for schwannomas but higher for neurofibromas, particularly in neurofibromatosis type 1. Magnetic resonance imaging is useful for defining the relationship of a swelling with adjacent nerves but is not definitive for tissue diagnosis. Increasing size, pain and neurological deficit suggest malignant change and TruCut needle biopsy is indicated, although there is a risk of sampling error. Excision biopsy preserving nerve function may be carried out for benign tumours to relieve symptoms. Malignant tumours require a multidisciplinary approach. Complete surgical excision with clear margins is the only curative treatment and may be supplemented with radiotherapy and chemotherapy. However, prognosis remains poor, particularly for patients with neurofibromatosis.

Immunotherapeutic treatments for spinal and peripheral nerve tumors: a primer.

OBJECTIVE: Spinal and peripheral nerve tumors are a heterogeneous group of neoplasms that can be associated with significant morbidity and mortality despite the current standard of care. Immunotherapy is an emerging therapeutic option to improve the prognoses of these tumors. Therefore, the authors sought to present an updated and unifying review on the use of immunotherapy in treating tumors of the spinal cord and peripheral nerves, including a discussion on mechanism of action, drug delivery, current treatment techniques, and preclinical and clinical studies. METHODS: Current data in the literature regarding immunotherapy were collated and summarized. Targeted tumors included primary and secondary spinal tumors, as well as peripheral nerve tumors. RESULTS: Four primary modalities of immunotherapy (CAR T cell, monoclonal antibody, viral, and cytokine) have been reported to target spine and peripheral nerve tumors. Of the primary spinal tumors, spinal cord astrocytomas had the most preclinical evidence supporting immunotherapy success with CAR T-cell therapy targeting the H3K27M mutation, whereas spinal schwannomas and ependymomas had the most evidence reported for monoclonal antibody therapy preclinically. Of the secondary spinal tumors, primary CNS lymphomas demonstrated some clinical response to immunotherapy, whereas multiple myeloma and bone tumor experiences with immunotherapy were largely limited to concept only. Within peripheral nerve tumors, the use of immunotherapy to treat neurofibromas in the setting of syndromes has been suggested in theory, and possible immunotherapeutic targets have been identified in malignant peripheral nerve tumors. To date, there have been 2 clinical trials involving spine tumors and 2 clinical trials involving peripheral nerve tumors that have reported results, all of which are promising but require validation. CONCLUSIONS: Immunotherapy to treat spinal and peripheral nerve tumors has become an emerging area of research and interest. A large amount of preclinical data supporting the translation of this therapy into practice, aimed at ameliorating the poor prognoses of specific tumors, have been reported. Future clinical studies for translation will focus on the optimal therapy type and administration route to best target these tumors, which often preclude total surgical resection given their proximity to the neural and vascular elements of the spine.

Review of Perineural Invasion in Keratinocyte Carcinomas.

Perineural invasion is an infiltrative process of peripheral nerves by the primary neoplasm within the immediate vicinity. Aggressive forms of keratinocyte carcinomas, such as basal cell and squamous cell carcinomas, may feature perineural invasion, which is often associated with tumor recurrence and poorer prognosis. Diagnosis requires a high clinical suspicion. Imaging and histopathology are used to assess for extent of disease while surgical excision with complete circumferential peripheral and margin assessment is the treatment goal. However, there is still significant uncertainty about adjuvant chemotherapy and definitive management guidelines. Here, we summarize the current understanding of this complex pathogenic process, the clinical presentation, and the significance of perineural inflammation. We also discuss the recommendations about staging, prognosis, adjuvant radiotherapy, and general guidelines for managing keratinocyte carcinomas with perineural invasion. A better understanding of perineural invasion is essential to improve diagnosis, tailor interventions, and mitigate patient morbidity and mortality.

Peripheral nerve neurolymphomatosis: Clinical features, treatment, and outcomes.

This series characterises nine patients with neurohistopathologically proven peripheral nerve neurolymphomatosis. A search of the hospital neuropathology database from 2002 to 2019 identified biopsy proven cases. Clinical data, investigation modalities, treatments, and outcomes were collated. Median age at neuropathy onset was 47 y, the neuropathy commonly as the initial lymphoma disease manifestation. Most (8/9) presented with painful asymmetrical sensory disturbance, with additional cranial nerve involvement in three. Neurophysiology typically demonstrated multiple axonal mononeuropathies. Cerebrospinal fluid protein was often raised (6/8). Magnetic resonance imaging suggested peripheral nerve infiltration in 6/9 and positron emission tomography CT in 4/9. Bone marrow biopsy was abnormal in 6/8. Treatment involved systemic or intrathecal chemotherapy and radiotherapy. Median survival was 23 mo. Neurolymphomatosis is a rare but important cause of neuropathy, particularly in those lacking systemic evidence of lymphoma as correct aggressive treatment can prolong survival. Nerve biopsy is essential to classify lymphoma type and rule out alternatives.

Malignant peripheral nerve sheath tumors: Analysis of the national cancer database.

OBJECTIVES: Malignant peripheral nerve sheath tumor (MPNST) is a rare type of soft tissue sarcoma (STS) that carries significant mortality. Given the rarity of MPNST, current knowledge on the disease is limited. We aim to characterize patient, tumor, and treatment factors, and determine variables associated with 5-year overall survival (OS) in individuals with MPNST. MATERIALS AND METHODS: We utilized the National Cancer Database (NCDB) to identify adult patients diagnosed with MPNST from 2004 to 2015, and analyze patient, tumor, treatment, and survival data. American Joint Committee on Cancer (AJCC 8) staging criteria for STS was utilized. RESULTS: In our cohort of 2,858 patients with MPNST, median age at diagnosis was 47. The 5-year OS rate was 52%. Age, race, tumor size, and treatment regimen significantly predicted 5-year OS on univariate analysis. AJCC 8 stage appeared to predict 5-year OS in head and neck tumors (though not significantly), but not trunk and extremity tumors. CONCLUSION: While our cohort of patients with MPNST are typically relatively young and healthy, 5-year OS is only 52%. Notably, age extremes, large tumor size, and certain treatment regimens are associated with worse outcomes. While AJCC 8 staging guidelines may have some value in predicting OS in head and neck tumors, they do not reliably risk stratify patients with trunk and extremity MPNST. Ultimately, MPNST is associated with high mortality with few modifiable risk factors, and survival may not be adequately predicted by current staging systems.

[Treatment of malignant peripheral nerve sheath tumors: case reports and a literature review]. / Lechenie zlokachestvennykh opukholei obolochek perifericheskikh nervov: sluchai iz praktiki i obzor literatury.

Malignant peripheral nerve sheath tumors (MPNSTs) are soft tissue sarcomas that develop from peripheral nerve sheath cells (T. Hirose, B.W. Scheithauer). These tumors are characterized by aggressive growth with an unfavorable outcome and may develop de novo or through malignant transformation of schwannomas, neurofibromas, or ganglioneuromas. MPNSTs are characterized by a rapid course and a poor prognosis. In this article, we reported cases of patients with malignant peripheral nerve tumors of the brachial plexus trunks and spinal localization.

Spinal Atypical Rhabdoid Teratoid Tumor in an Adult Woman: Case Report and Review of the Literature.

BACKGROUND: Atypical rhabdoid teratoid tumors are very rare embryonal tumors that typically affect children younger than 3 years old and are encountered intracranially. CASE DESCRIPTION: Here, we describe the case of a 19-year-old woman who presented with gait disturbances and coccydynia. Imaging revealed a cauda equina mass. The tumor was partially resected. Histology reported loss of SMARCB1/INI1 expression and therefore the diagnosis of atypical rhabdoid teratoid was established. The patient underwent radiation treatment, but within 3 months 2 relapses were manifested. CONCLUSIONS: Atypical rhabdoid teratoids are exceptionally rare in adults and are seldom found in spine; only 8 such cases have been reported in the medical literature. They are invariantly characterized by multiple relapses and dismal prognosis. The clinician must be attentive of leptomeningeal disseminations and 22q11 deletion-associated comorbidities.

Peripheral nerve injuries in the pediatric population: a review of the literature. Part III: peripheral nerve tumors in children.

INTRODUCTION: Peripheral nerve tumors type, inciedence and treatment in the pediatric population should be analyzed. METHODS: We have performed an extense literature review of this subject. RESULTS: incidence and distribution are similar to those observed in adults. The most common peripheral nerve tumors in children are neurofibromas and schwannomas. Malignant peripheral nerve sheath tumors are also observed, specially associated with genetic syndromes, like neurofibromatosis and Carney complex. CONCLUSION: In this review, peripheral nerve tumors have been divided into three categories to aid with understanding: reactive and hyperplastic lesions, benign tumors, and malignant tumors. The most frequent lesions have been described.

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

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

Plexus and peripheral nerve metastasis.

Cancer in the form of solid tumors, leukemia, and lymphoma can infiltrate and metastasize to the peripheral nervous system, including the cranial nerves, nerve roots, cervical, brachial and lumbosacral plexuses, and, rarely, the peripheral nerves. This review discusses the presentation, diagnostic evaluation, and treatment options for metastatic lesions to these components of the peripheral nervous system and is organized based on the anatomic distribution. As skull base metastases (also discussed in Chapter 14) result in cranial neuropathies, these will be covered in detail, as well as cancers that directly infiltrate the cranial nerves. Particular emphasis is placed on the clinical, imaging, and electrodiagnostic features that differentiate neoplastic plexopathies from radiation-induced plexopathies. Neurolymphomatosis, in which malignant lymphocytes invade the cranial nerves, nerve roots, brachial and lumbosacral plexuses, and peripheral nerves, is a rare manifestation of lymphoma and leukemia. Diagnoses of neurolymphomatosis are often missed or delayed given its varied presentations, resulting in poorer outcomes. Thus this disease will also be discussed in depth.

Intraneural perineurioma: a retrospective study of 19 patients.

Intraneural perineurioma is a benign neoplasm of peripheral nerve sheath with perineurial cell origin that typically affects teenagers and young adults and tends to result in a motor-predominant neuropathy. The aim of our study is to present the epidemiology, clinical presentation, way of diagnosis and management plan in a consecutive patient series. Ninteen patients diagnosed as having intraneural perineurioma were retrospectively chart reviewed. Diagnosis was done by MRI and/or biopsy with morphological, immunohistochemical staining study confirmation. Patients assessments included gender, age, symptoms, tumor localization, radiological aspect, management and pathological confirmation.Sex ratio was 10 males to 9 females with mean age of 31.2 (15-64). All the patients presented with motor deficit, ten with sensory deficit. Upper limb was involved in 11 cases (among them 4 lesions of brachial plexus), the lower limb in 8 cases. On magnetic resonance imaging, 16 patients showed a nerve enlargement whereas 5 presented with atypical fusiform tumor. Eighteen patients were operated for excision biopsy and/or palliative treatment for their motor deficit. Anatomopathological analysis confirmed the diagnosis in seventeen cases with a morphological pseudo-onion bulb shape and/or specific immunohistochemical assay. One patient had only palliative treatment without excision biopsy. Our data confirmed the equal penetration of intraneural perineurioma to both sex and affected limb. Because of the benignity of the tumor, the surgical treatment focused on optimizing the functional outcome. A prospective study with long term follow-up is required for this under-diagnosed tumor.

Peripheral Interventions for Painful Stump Neuromas of the Lower Limb: A Systematic Review.

OBJECTIVES: Painful stump neuromas in lower limb amputees are a significant burden on a person's quality of life due to interference with wearing prostheses and therefore the ability to walk. Treating painful stump neuromas is a challenge perhaps reflected by the lack of clinical guidelines. MATERIALS AND METHODS: A systematic review was conducted to evaluate the efficacy of all treatments tried in the management of symptomatic neuromas in the lower limb amputation stump in order to establish whether one treatment is superior. RESULTS: Twenty-two studies were included in the final review which examined 14 different treatments both surgical and nonsurgical. Results showed that no single treatment showed superiority. DISCUSSION: The 4 treatments that showed most promise included targeted nerve implantation, traction neurectomy, nerve-to-nerve anastomosis, and perineurial gluing. The short follow-up times and small sample sizes of the studies highlighted the need for more robust clinical studies.

Review of periorbital nerve enlargement and biopsy techniques.

Periorbital nerve enlargement commonly indicates perineural invasion of malignancy or inflammatory conditions. This study reviews the role of supraorbital and infraorbital nerve biopsies in patients presenting with radiographic enlargement and to elucidate the surgical technique involved. A retrospective chart review (1997-2014) was performed at a single tertiary center. Patients with radiographic confirmation of enlarged supraorbital/infraorbital nerves that underwent biopsy were included. Charts were reviewed for: patient demographics and history, clinical symptoms and findings, radiographic findings, surgical method, and treatment. Five patients (4 female, 1 male) met inclusion criteria. Average age was 72.4 years (range 36-90). Four patients had history of cutaneous malignancy. All presented with diplopia and/or dysesthesias. Clinical examination confirmed decreased V1 and/or V2 sensation for 4 patients. Imaging revealed enlargement of V1, V2, and/or V3 in all patients. Infraorbital nerve biopsies were performed in 3 patients via transconjunctival fornix-based orbitotomy with subperiosteal dissection along orbital floor followed by unroofing of infraorbital canal. The remaining 2 underwent supraorbital nerve biopsy via sub-brow incision onto superior orbital rim with reflection of periosteum. Biopsies confirmed squamous cell carcinoma(3), mucoepidermoid carcinoma(1), and idiopathic orbital inflammation(1). Three patients initiated treatment in <1 month. One decided to follow-up closer to home, one was lost to follow-up. For patients presenting with enlarged supraorbital/infraorbital nerves, biopsy can rapidly confirm the underlying condition and facilitate early treatment. A sub-brow approach offers direct access to supraorbital nerve while transconjunctival fornix-based anterior orbitotomy with canal unroofing allows access to infraorbital nerve.

The efficacy of lapatinib and nilotinib in combination with radiation therapy in a model of NF2 associated peripheral schwannoma.

Neurofibromatosis type 2 (NF2), a neurogenetic condition manifest by peripheral nerve sheath tumors (PNST) throughout the neuroaxis for which there are no approved therapies. In vitro and in vivo studies presented here examine agents targeting signaling pathways, angiogenesis, and DNA repair mechanisms. In vitro dose response assays demonstrated potent activity of lapatinib and nilotinib against the mouse schwannoma SC4 (Nf2 -/-) cell line. We then examined the efficacy of everolimus, nilotinib, lapatinib, bevacizumab and radiation (RT) as mono- and combination therapies in flank and sciatic nerve in vivo NF2-PNST models. Data were analyzed using generalized linear models, two sample T-tests and paired T-tests, and linear regression models. SC4(Nf2 -/-) cells implanted in the flank or sciatic nerve showed similar rates of growth (p = 0.9748). Lapatinib, nilotinib and RT significantly reduced tumor growth rate versus controls in the in vivo flank model (p = 0.0025, 0.0062, and 0.009, respectively) whereas bevacizumab and everolimus did not. The best performers were tested in the in vivo sciatic nerve model of NF2 associated PNST, where chemoradiation outperformed nilotinib or lapatinib as single agents (nilotinib vs. nilotinib + RT, p = 0.0001; lapatinib versus lapatinib + RT, p < 0.0001) with no observed toxicity. There was no re-growth of tumors even 14 days after treatment was stopped. The combination of either lapatinib or nilotinib with RT resulted in greater delays in tumor growth rate than any modality alone. This data suggest that concurrent low dose RT and targeted therapy may have a role in addressing progressive PNST in patients with NF2.

[Neurology]. / Neurologie.

Aducanumab reduces the burden of amyloid plaques in Alzheimer's disease, with significant improvement of clinical scores. Endovascular thrombectomy is recommended in patients with acute stroke with proximal occlusion of the anterior circulation. CGRP antagonists and botulinum toxin are effective in migraine. ZIKA virus infection has been linked to the Guillain-Barré syndrome. Edaravone has been approved for amyotrophic lateral sclerosis. Two monoclonal antibodies (ocrelizumab and daclizumab) and siponimod show positive results in multiple sclerosis. Thalamotomy of ventral intermediate nucleus (by gamma-knife or by magnetic resonance-guided focused ultrasound) is effective in drug-resistant essential tremor. The dose-dependent risk of foetal malformations associated with valproate and topiramate is confirmed.

L'aducanumab réduit la présence de plaques amyloïdes dans la maladie d'Alzheimer, avec amélioration significative des scores cliniques. Dans l'AVC aigu, la thrombectomie endovasculaire est recommandée en présence d'une occlusion proximale de la circulation antérieure. La toxine botulinique est efficace dans la migraine chronique. L'infection à virus Zika est associée au syndrome de Guillain-Barré. L'édaravone a été approuvé pour la sclérose latérale amyotrophique. Deux anticorps monoclonaux (ocrélizumab et daclizumab) et le siponimod montrent des résultats positifs dans la sclérose en plaques. La thalamotomie du noyau ventral intermédiaire par gamma-knife et par ultrasons focalisés guidés par résonance magnétique est efficace dans le tremblement pharmaco-résistant. Le risque dose-dépendant de malformations fœtales liées au valproate et au topiramate est confirmé.

Tumors of the hand.

Tumors of the hand comprise a vast array of lesions involving skin, soft tissue and bone. The majority of tumors in the hand are benign. Malignant tumors, although rare, do occur and frequently have unique characteristics in this specific anatomic location. Careful staging, histological diagnosis and treatment are essential to optimize clinical outcome. However, straightforward most of the time, hand tumor management does have pitfalls; caution is advised, as a missed or delayed diagnosis or an improperly executed biopsy may have devastating consequences. This article reviews the clinical spectrum of the most common benign and malignant bone and soft tissue tumors of the hand and discusses the clinicopathological findings, imaging features and current concepts in treatment for these tumors.

Unique Considerations in Spinal Cord Stimulator Placement in Pediatrics: A Case Report.

Spinal cord stimulation can be a valuable treatment option in the management of neuropathic pain in select pediatric patients. We present a unique case of a 16-year-old girl with Klippel-Trenaunay-Weber syndrome and scoliosis who required the placement of a spinal cord stimulator (SCS) for severe sciatic nerve neuropathic pain after a right above-knee amputation. Several attempts at lead placement were required before successful pain coverage was achieved because of late recognition of significant vertebral body rotation. This case highlights important considerations in pediatric SCS placement including a careful review of the spinal cord anatomy before the placement of an SCS.