Atypical and malignant peripheral nerve-sheath tumors of the brachial plexus: report of three cases and review of the literature

Patient demographics, tumor characteristics, and outcomes following surgical treatment of benign and malignant brachial plexus tumors: a systematic review

BACKGROUND

Various treatment options have been introduced for the management of primary tumors of the brachial plexus (BP), ranging from conservative therapy to wide local excision with/without postoperative chemoradiotherapy. However, no consensus exists regarding optimal treatment strategies based on collated and published data.

OBJECTIVE

The aim of this study was to investigate the clinicopathological characteristics and outcome of patients with primary tumors of the BP who underwent surgical treatment.

DATA SOURCES

A systematic search of the four main online databases, including Web of Science (WOS), PubMed, Scopus, and Google Scholar, was conducted.

STUDY SELECTION

All related articles addressing the clinical outcome and role of surgical interventions for management of primary tumors of the BP.

INTERVENTION

Optimal surgical and radiotherapeutic interventions for benign and malignant lesions based on the pathologic characteristics and location of primary BP tumors.

RESULTS

A total of 687 patients (693 tumors) with a mean age of 41.7±8.7 years old were evaluated. In total, 629 (90.8%) tumors were benign, and 64 (9.2%) were malignant, with a mean tumor size of 5.4±3.1 cm. The location of the tumor was reported for 639 patients. For these tumors, 444 (69.5%) originated from the supraclavicular region, and 195 (30.5%) were infraclavicular. The trunks were the most common location for tumor involvement, followed by the roots, cords, and terminal branches. Gross total resection was achieved in 432 patients and subtotal resection (STR) was performed in 109 patients. With neurofibromas, STR still resulted in good outcomes. The outcomes following treatment of malignant peripheral nerve sheath tumors were poor regardless of the type of resection. In general, symptoms related to pain and sensory issues resolved rapidly postoperatively. However, the resolution of motor deficits was often incomplete. Local tumor recurrence occurred in 15 (2.2%), patients and distant metastasis was observed in only eight (1.2%) cases. The overall mortality was 21 (3.1%) patients among the study population.

LIMITATIONS

The main limitation was the lack of level I and II evidence.

CONCLUSIONS

The ideal management strategy for primary BP tumors is complete surgical resection. However, in some cases, particularly for neurofibromas, STR may be preferable to preserve maximal neurological function. The degree of surgical excision (total or subtotal) mainly depends on the pathological characteristics and primary location of the tumor.

Malignant Peripheral Nerve Sheath Tumors of the Brachial Plexus: A Single-Center Experience on Diagnosis, Management, and Outcomes

INTRODUCTION

The incidence of malignant peripheral nerve sheath tumors (MPNSTs) is 0.001%. Commonly, MPNST arise in neurofibromatosis; however, they can occur sporadically, de novo or from a preexisting neurofibroma. Malignant peripheral nerve sheath tumors are aggressive tumors with high rates of local recurrence and metastasis. The prognosis is poor with 5-year survival rates of 15% to 50%. Unfortunately, given the rarity of these tumors, it is not clear how to best manage these patients. The purposes of this study were (1) to discuss our experience with MPNST and particularly our difficulties with diagnosis and management, and (2) to review the literature.

MATERIALS AND METHODS

We report on all tumors of the brachial plexus excised between 2013 and 2019. We report 3 cases of MPNST, their treatment, and their outcomes.

RESULTS

Thirteen patients underwent surgical excision of an intrinsic brachial plexus mass. Three of these patients (2 male, 1 female; average age, 36 years) were diagnosed with an MPNST. Two patients with an MPNST had neurofibromatosis type 1. All patients with an MPNST had a tumor >8 cm, motor and sensory deficits, and pain. All 3 patients with MPNST underwent a magnetic resonance imaging (MRI) before diagnosis. The average time from initial symptom onset to MRI was 12.3 months. Only 1 of the MRIs suggested a malignant tumor, with no MRI identifying an MPNST. One patient underwent an excisional biopsy, and 2 had incisional biopsies. Because of the lack of diagnosis preoperatively, all patients had positive margins given the limited extent of surgery. Returning for excision in an attempt to achieve negative margins in a large oncologically contaminated field was not possible because defining the boundaries of the initial surgical field was unachievable; therefore, the initial surgery was their definitive surgical management. All patients were referred to oncology and received radiation therapy.

CONCLUSIONS

Malignant peripheral nerve sheath tumors must be suspected in enlarging masses (>5 cm) with the constellation of pain, motor, and sensory deficits. Computed tomography- or ultrasound-guided core needle biopsy under brachial plexus block or sedation is required for definitive diagnosis to allow for a comprehensive approach to the patient's tumor with a higher likelihood of disease-free survival.

The gene diagnosis of neurofibromatosis type I with headache as the main symptom: A case report and review of the literature

Neurofibromatosis type I (NF1) is an autosomal dominant disease. Some NF1 patients experience atypical clinical manifestations, genetic testing is not widely available, and the types of mutations vary; thus, they are prone to misdiagnosis and missed diagnosis. Although headache is not included in the diagnostic criteria for NF1, the incidence of headache in NF1 patients is not low. We report an NF1 family in which the proband presented with prominent headache and atypical clinical presentation, with limited skin pigmentation. We identified a frameshift mutation (c.1541_1542del, p. Q514Rfs*) in the NF1 gene by whole-exome sequencing of this family, and the patients were diagnosed with NF1. We hope to attract the attention of clinicians to these patients and improve genetic testing as soon as possible to increase the diagnosis rate.

Electrodiagnostic Assessment of Plexopathies

Disorders of the brachial and lumbosacral plexus are complex and may occur as a consequence of trauma, compression, inflammatory disorders, malignant infiltration, or delayed effects of radiation therapy. An understanding of plexus anatomy and surrounding structures will allow the electromyographer to facilitate an efficient and comprehensive assessment of the plexus. A careful and thorough electrodiagnostic assessment allows for localization within the plexus and may provide important information about underlying pathology and prognosis.

Intracranial metastasis from a malignant peripheral nerve sheath tumor in a patient with neurofibromatosis type 1: A case study and literature review

INTRODUCTION

Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are a rare type of soft tissue sarcoma. While these tumors often metastasize, intracranial metastases of MPNSTs have only been rarely noted.

METHODS

Using Pubmed, Google Scholar, and Science Direct we conducted a systematic review of the literature to identify all reported cases of MPNSTs with metastases to the brain since the inception of these databases through January 2020. Data were extracted and data analysis was completed using python statistical packages.

RESULTS

Only 26 cases (including present study) of MPNSTs resulting in intracranial metastases have been reported in the literature. Eight of these 26 cases occurred in patients who were previously diagnosed with Neurofibromatosis Type 1 (NF1). Additionally, one patient had been previously diagnosed with Neurofibromatosis Type 2 (NF2). The average reported time from diagnosis of a MPNST to the time of diagnosis with intracranial metastasis was 36 months, with a median time of 14 months. The average reported survival time for patients after being diagnosed with intracranial metastasis was 5.9 months. The cases that utilized a combination of therapeutic intervention including surgical resection, radiotherapy and chemotherapy saw the greatest improvement of survival times.

CONCLUSION

MPNSTs with brain metastases are extremely rare and have a poor prognosis with a 6 months median survival after metastasis. While combination therapy is indicated, further studies on treatment are needed to determine survival benefits. Early and effective initial diagnosis of MPNST before brain metastases occurs is likely to give the best chance of increased overall survival.

Management of benign nerve sheath tumors of the brachial plexus: relevant diagnostic and surgical features. About a series of 17 patients (19 tumors) and review of the literature

Brachial plexus (BP) tumors are rare, potentially difficult-to-manage lesions. The method is retrospective chart analysis. Among the 17 patients, four had neurofibromatosis and one schwannomatosis (NF +). The latter has bilateral BP tumors that remain stable on MRI at a 6.5 year follow-up. Another NF + patient has bilateral non-operable BP plexiform neurofibromas. The complaints of the 15 operated patients were radiated pain, a mass, local pain, paresthesia, a neurological deficit (n = 15, 12, 7, 10, 7). On MRI, the tumors appeared as nodular or ovoid large masses. Four operated tumors were proximal, reaching the foramen. The FDG-PET scan (n = 4) always showed tumor hypermetabolism. A preoperative percutaneous biopsy was done in three patients before neurosurgical consultation; one of them developed neurogenic pain and a sensory deficit following two percutaneous biopsies for a misinterpreted cervical lymphadenopathy. Surgery was performed using a supra-, infra-, supra- + infra-clavicular or posterior subscapular approach (n = 8, 3, 3, 1). Intraoperative electrophysiology was used in all patients. Complete or gross total resection was achieved in 14 patients. Two patients had fascicle reconstruction with grafts. Pathology revealed 13 schwannomas and two neurofibromas. Neurogenic pain transiently developed or worsened after surgery in five patients. At last follow-up, a mild deficit remained in four patients (preexisting in three). No recurrence had occurred. We conclude that a thorough examination of any patient with a cervical or axillary mass is crucial to avoid misinterpretation as a lymphadenopathy. MRI is the best imaging modality. Most BP benign tumors can be completely and safely resected through the use of microsurgical techniques and intraoperative electrophysiology.

Medullary metastasis of a malignant peripheral nerve sheath tumor: A case report

The present study reports a case of medullary metastasis without lung metastasis that occurred as a result of a malignant peripheral nerve sheath tumor (MPNST). An 81-year-old woman presented with a MPNST in the left brachial plexus, arising from the cervical nerve root. The patient underwent carbon ion radiotherapy; however, tumor recurrence was identified in the left shoulder. Subsequently, the patient underwent wide excision. Three weeks subsequent to surgery, imbalance and dysarthria developed suddenly. Dysphagia emerged and left upper limb pain disappeared on the day after symptom development. Magnetic resonance imaging (MRI) revealed that this was due to metastasis to the medulla. Five days subsequent to the onset of dysarthria, the patient succumbed due to respiratory failure. To the best of our knowledge, no previous cases of medullary metastasis arising from a MPNST in the absence of lung metastasis have been reported. MRI is a useful examination tool for the identification of brain metastases; however, the high cost of MRI as a routine examination must be considered due to the rarity of brain metastases. Therefore, methods to detect brain metastasis warrant further investigation.

Management of brachial plexus region tumours and tumour-like conditions: relevant diagnostic and surgical features in a consecutive series of eighteen patients

BACKGROUND

Tumours of the brachial plexus region are rare and most publications are case reports or studies with a small series of patients. The aim of this study is to present our experience in managing these lesions.

METHODS

We review 18 patients with tumours in the brachial plexus region submitted to surgical treatment in a 6 year period, including their clinical presentation, neuro-imaging data, surgical findings and outcome.

FINDINGS

The tumours comprised a heterogeneous group of lesions, including schwannomas, neurofibromas, malignant peripheral nerve sheath tumour (MPNST), sarcomas, metastases, desmoids and an aneurysmal bone cyst. The most common presentation was an expanding lump (83.33%). Eleven tumours were benign and 7 were malignant. Neurofibromatosis was present in only 2 patients (11.11%). Gross total resection was achieved in 14 patients and sub-total resection in the others. Only 3 patients presented with new post-operative motor deficits. The incidence of complications was low (16.5 %).

CONCLUSIONS

The majority of tumours were benign and most of them could be excised with a low incidence of additional deficits. Some of the malignant tumours could be controlled by surgery plus adjuvant therapy, but this category is still associated with high morbidity and mortality rates.

Update on the management of familial central nervous system tumor syndromes

Hereditary central nervous tumor syndromes are a varied group of conditions that include neurofibromatosis type 1 and 2, tuberous sclerosis, Von Hippel-Lindau disease, and Cowden, Turcot, and Gorlin syndromes. The responsible genes have been identified in most of these disorders. These genes typically act as tumor suppressor genes, maintain normal cellular function and homeostasis, and regulate cell growth and differentiation. Familial central nervous system tumors are mostly inherited as autosomal dominant traits and involve germline mutations. Neoplastic development occurs when a somatic mutation inactivates the second allele. These patients also present unique challenges for their management. This review highlights the clinical manifestations, molecular genetics, pathophysiology, and current treatment options of these disorders with a focus on neuro-oncologic manifestations of the diseases.