A series of 397 peripheral neural sheath tumors: 30-year experience at Louisiana State University Health Sciences Center

All-Endoscopic Resection of an Infraclavicular Brachial Plexus Schwannoma: Surgical Technique

Due to recent progress in shoulder arthroscopy, all-endoscopic brachial plexus (BP) dissection has progressively become a standardized procedure. Based on previously described techniques, we present an additional neurological procedure that may be performed all-endoscopically, that is, the excision of an infraclavicular BP schwannoma. Starting from a standard shoulder arthroscopy with posterior and lateral portals, additional anterior and medial portals are progressively opened outside the joint under endoscopic control to access the BP. At first, dissection of the subcoracoid space allows the identification of the posterior and lateral cords, along with the axillary artery. Then, by performing a pectoralis minor tenotomy, the medial cord and axillary vein are exposed, giving access to the whole infraclavicular plexus. Intraneural dissection is performed using arthroscopic tools such as a long beaver blade, a grasper, and a smooth dissector to progressively extract the encapsulated tumor from the nerve without any damage. Using a standardized technique, endoscopy may be an advantageous tool in selected cases of BP benign peripheral nerve sheath tumors.

Demographic, Clinical and Histopathological Features of Oral Neural Neoplasms: A Retrospective Study

Intraoral neural neoplasms though unusual may be clinically significant. The aim of this study was to categorize and evaluate oral neural tumors in a large oral pathology biopsy service. With IRB approval, a retrospective search of all neural neoplasms of the oral cavity in the archives of the University of Florida Oral Pathology Biopsy Service spanning from 1994 to 2015 was performed. Extraoral cases as well as cases with insufficient patient information were excluded. A total of 340 out of 164,578 submitted specimens in a 22 year period (0.2%) were included with a mean age of 43.3 years (range: 6-89), and 44% male and 56% female. The most commonly affected locations were: tongue (37.5%), palate (22%), lip (19%), and gingiva (14%). The microscopic diagnoses rendered, in descending order of frequency were: neurofibromas (NFs): 123 (36%), granular cell tumor (GCT): 108 (32%), schwannomas: 61 (17%), palisaded encapsulated neuromas: 39 (11%), benign neural lesion not otherwise specified: 8 (2%), and mucosal neuroma c/w multiple endocrine neoplasia type 2B (MEN 2B): 1 (< 0.5%). Six cases of NF reported a history of neurofibromatosis Type 1 (NF 1). Four cases showed multifocal lesions. Immunohistochemical staining was performed on equivocal cases (25% of the lesions) and all were confirmed by their S-100 positivity. Intraoral neural neoplasms, though uncommon should be in the differential diagnosis of oral soft tissue entities and specific consideration to syndromal linkage is paramount as this may impact patient management.

Case Report: An incidental finding of an metastases noted in a "cancer to cancer adrenal tumor " from a large malignant nerve sheath tumor of the thigh

Current guidelines are vague for the management of soft tissue sarcomas, specifically malignant peripheral nerve sheath tumors (MPNST), regarding staging the disease with the use of routine abdominal imaging. The most recent guidelines from the National Comprehensive Cancer Network (NCCN) recommends to “consider” abdominal/pelvic CT imaging for certain sub groups of sarcomas (e.g., myxoid/round cell liposarcoma, epithelial sarcoma, angiosarcoma,  leiomyosarcoma), but provide no guidance on other sarcoma subtypes regardless of tumor size. We report a case of a very large large MPNST  in a 40 year-old-female with neurofibromatosis type 1 who was incidentally found to have adrenal metastasis.

Brachial Plexus Schwannoma - Case Report and Literature Review

SUMMARY – Schwannoma as an extracranial nerve sheath tumor rarely affects brachial plexus. Due to the fact that brachial plexus schwannomas are a rare entity and due to the brachial plexus anatomic complexity, schwannomas in this region present a challenge for surgeons. We present a case of a 49-year-old female patient with a slow growing painless mass in the right supraclavicular region that was diagnosed as schwannoma and operated at our department. The case is described to remind that in case of supraclavicular tumors, differential diagnosis should take brachial plexus tumors, i.e. schwannomas, in consideration. Extra caution is also required on fine needle aspiration procedures or biopsies of schwannomas due to the possible iatrogenic injury of the nerve and adjacent structures. On operative treatment of schwannoma, complete tumor resection should be achieved while preserving the nerve.

The Surgical Management of Symptomatic Benign Peripheral Nerve Sheath Tumors of the Neck and Extremities: An Experience of 442 Cases

BACKGROUND

The occurrence of benign peripheral nerve sheath tumors (PNSTs) is not uncommon. The surgical excision of symptomatic benign PNSTs along with preservation of the affected nerve and its function is an ideal treatment option.

OBJECTIVE

To analyze the outcome with respect to morbidity, extent of resection, and recurrence, and to review and compare our results with those reported in literature.

METHODS

A retrospective review of clinical and radiological findings of 442 patients with benign PNSTs involving the neck and extremities treated surgically from 2000 to 2014 was performed.

RESULTS

In our series, benign PNSTs involved the extremities in 290 (65.6%) patients and the brachial plexus in 146 (33%) patients, and 6 (1.4%) patients had tumors of the extracranial portion of the vagus and hypoglossal nerves in the neck. The mean age of patients was 38 yr. The presenting features were painful mass and paresthesia. Preoperative motor weakness in the extremity was noted in 15.6% of patients. The common nerves involved by the tumors were the ulnar nerve (15.8%), sciatic nerve (12.7%), and upper cervical roots (11.5%). The excision was total in 81.2%, gross total (>90%) in 17.9%, and subtotal (>50%) in 0.9% patients. In 17.6% of patients, there was severe postoperative neurogenic pain. In 28 (6.3%) patients, a new motor deficit was noted following surgery. Recurrence was seen in 2 patients in our series. The mean follow-up was 30.2 mo.

CONCLUSION

Benign PNSTs have excellent clinical outcome, and the goal for surgical treatment is total to gross total excision of the tumor with neural preservation.

Targeted next-generation sequencing of malignant peripheral nerve sheath tumor of the pterygopalatine fossa with intracranial metastatic recurrence

Malignant peripheral nerve sheath tumor (MPNST) is an uncommon neoplasm that rarely involves the head and neck region. Intracranial MPNSTs unrelated to cranial nerves are highly malignant tumors with poor overall survival, probably because of infiltrating growth into surrounding brain tissue. The pathogenesis of MPNST remains unclear. There are no conclusive explanations for the mechanisms underlying the initiation, progression, and metastasis of MPNST. In this paper, we describe a case of MPNST in the pterygopalatine fossa with intracranial metastatic recurrence and review related literatures. Meanwhile, targeted next-generation sequencing (NGS) revealed the presence of both a beta-catenin (CTNNB1) missense mutation p.Ser33Phe and a mediator complex subunit 12 (MED12) frameshift mutation p.Tyr1278fs in the recurrent intracranial tumor. Therapies that target CTNNB1 mutation, MED12 mutation, CTNNB1 activation, or Wnt pathway activation are worth future studying.

Chronic Calf Pain Caused by Fibroma-Induced Chronic Inflammation Around the Tibial and Peroneal Nerves that Was Misdiagnosed as Centralized Neuropathic Pain: A Case Report

INTRODUCTION

The etiology of calf pain varies widely; therefore, it is difficult to diagnose and requires careful history taking and physical examination by primary care unit physicians. Because ultrasonography is easy to perform, cheap, and readily available to physicians during a routine consultation, it is the first choice of modality for the evaluation of calf pain. However, simple inflammation around the nerve should also be considered as a possible etiology. Here we describe a 35-year-old man with chronic pain in the right calf that was actually caused by fibroma-induced chronic inflammation around the tibial and peroneal nerves but misdiagnosed as centralized neuropathic pain.

CASE REPORT

The patient presented with chronic pain and a tingling sensation in the right calf. He had a slowly growing tibial nerve neurilemmoma that was excised at 28 years of age; however, the pain and tingling sensation persisted. He visited several hospitals for 7 years and was misdiagnosed with peripheral nerve injury-induced neuropathic pain. At 35 years of age, he visited our hospital for further evaluation. Ultrasonography revealed a mass in the popliteal region, which was excised and confirmed to be a fibroma via histopathological analysis. Severe inflammation was observed in the operative field. His symptoms finally ameliorated after this surgery.

CONCLUSION

The findings from this case suggest that ultrasonography should be used as the primary modality for the evaluation of calf pain. Although the features of unresolved calf pain are similar to those of neuropathic pain, more curable etiologies should be considered.

Peripheral nerve sheath tumors of the upper extremity and hand in patients with neurofibromatosis type 1: topography of tumors and evaluation of surgical treatment in 62 patients

Objective: Neurofibromatosis type 1 (NF1) is an autosomal dominant tumor predisposition syndrome with a tendency to develop peripheral nerve sheath tumors (PNST). Plexiform neurofibromas (PNF) are detected in a high proportion of affected patients. The tumors can lead to severe disfigurement and are classified as precancerous. This study examines the surgical procedures that have been performed on large PNST of the upper limb and hand, and investigates whether a specific distribution pattern of the tumors can be detected in surgically treated cases.

Methods: Surgical procedures on the upper extremity and hand performed on patients with NF1 were evaluated at an interval of 25 years (1992–2016). Topography of the tumors was classified according to dermatomes. The number of interventions per patient, duration of operations, and complications of the interventions were registered. An overview of the surgical treatment of PNST of the upper limb and hand was obtained from the literature, with special consideration of the genetic background of treated tumors.

Results: One hundred and sixty-three surgical interventions on the upper limb and hand were performed in 62 patients with NF1 for the treatment of large PNST, predominantly PNF (age: mean value: 27.33 years, male: 33, female: 29; right side: 25, left side: 26, bilateral: 7). Surgical procedures lasted an average of 72.47 minutes. In approximately half of the patients, one surgical procedure was sufficient. Duration of stay in hospital was on average 7–11 days. Neurological complications were rarely noted and occurred only temporarily. There were no dermatomes affected by PNF with particular frequency. However, some dermatomes were more often simultaneously affected by a PNF at the same time as others.

Conclusion: Although the distribution pattern shows some accumulation of tumor localization, tumors are distributed evenly and show very variable size and extent in individual cases. Surgical treatment of PNF of the upper limb and hand helps alleviate the physical discomfort that these patients have from their disfiguring disease. Repeated interventions are necessary relatively often in order to adapt the tumorous region to the outline of the limb and to improve its function.

Synovial sarcoma mimicking benign peripheral nerve sheath tumor

OBJECTIVE

To assess the radiographic and clinicopathologic features of synovial sarcoma of the nerve that were clinically or radiologically interpreted as benign peripheral nerve sheath tumor.

MATERIALS AND METHODS

Five patients with synovial sarcoma arising from the peripheral nerve and interpreted clinically and radiologically as peripheral nerve sheath tumors were identified. Clinicopathologic and imaging features were evaluated.

RESULTS

There were three females and two males, ranging in age from 28 to 50 (mean 35.8) years. Most patients (4/5) complained of a mass, discomfort or pain. MR images demonstrated a heterogeneous, enhancing, soft tissue mass contiguous with the neurovascular bundle. On histologic examination, most tumors were monophasic synovial sarcoma (4/5). At the time of surgery, all tumors were noted to arise along or within a peripheral nerve. All patients were alive with no evidence of disease with median follow-up of 44 (range 32-237) months. For comparison, approximately 775 benign peripheral nerve sheath tumors of the extremities were identified during the same time period.

CONCLUSIONS

Primary synovial sarcoma of the nerve can mimic peripheral nerve sheath tumors clinically and on imaging and should be included in the differential diagnosis for tumors arising from peripheral nerves.

Histopathological Spectrum of Soft-Tissue Tumors with Immunohistochemistry Correlation and FNCLCC grading: A North Indian Experience

INTRODUCTION

Soft tissue tumors (STT) are mesenchymal neoplasms with a diverse spectrum and overlapping clinical, radiological and histological features. Histopathology and immunohistochemistry (IHC) are essential to make a diagnosis. Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) Sarcoma Group grading system based on tumour differentiation, mitotic rate and necrosis helps in predicting the tumour progression and treatment response.

AIMS

The goal of this study was to analyze the incidence, histological spectrum and IHC features of STTs and to grade sarcomas according to FNCLCC grading system.

MATERIAL AND METHODS

This is a four year study conducted in the Department of Pathology of a tertiary care centre from July 2009 to June 2013. All histopathologically diagnosed STTs were evaluated for gross and microscopic appearance. IHC was done wherever needed and clinical correlation was attempted. Sarcomas were graded according to FNCLCC grading system.

RESULTS

Of the total 270 cases studied, benign, intermediate and malignant STTs were 67.0%, 7.0% and 25.9% respectively. Adipocytic, vascular and peripheral nerve sheath tumors (PNST) formed the bulk of overall STTs (34.1%, 18.5% and 11.1% respectively). Sarcomas not otherwise specified were found to be the most common soft-tissue sarcomas followed by smooth muscle sarcomas and tumors with uncertain differentiation (11.5%, 4.1%, and 3.3%, respectively). Benign STTs were seen two decades earlier and were superficial in location as compared to sarcomas. On FNCLCC grading, grade 3 soft tissue sarcomas were slightly higher in number than grade 2 (27 vs 24). On IHC a definitive diagnosis was reached in 33 malignant, all intermediate and nine benign cases.

CONCLUSION

The incidence of intermediate and malignant STTs is increasing due to early detection and better diagnosis by ancillary techniques like IHC. FNCLCC grading helps to prognosticate the malignant STTs thus guiding further plan of action while in some tumors like MPNST and Angiosarcoma it has no prognostic significance.

Management of peripheral nerve sheath tumors: 17 years of experience at Toronto Western Hospital

OBJECTIVE A surgical series of 201 benign and malignant peripheral nerve sheath tumors (PNSTs) was assessed to characterize the anatomical and clinical presentation of tumors and identify predictors of neurological outcome, recurrence, and extent of resection. METHODS All surgically treated PNSTs from the Division of Neurosurgery at Toronto Western Hospital from 1993 to 2010 were reviewed retrospectively. Data were collected on patient demographics, clinical presentation, surgical technique, extent of resection, postoperative neurological outcomes, and recurrence. RESULTS One hundred seventy-five patients with 201 tumors had adequate follow-up for analysis. There were 182 benign and 19 malignant PNSTs. Of the benign lesions, 133 were schwannomas, 21 of which were associated with a diagnosis of schwannomatosis. There were 49 neurofibromas, and 26 were associated with neurofibromatosis Type 1 (NF1). Patients presenting with schwannomas were significantly older than those with neurofibromas. Schwannomas were more readily resected than neurofibromas, with the extent of resection of the former influenced by tumor location. Patients with benign PNSTs typically presented with a painful mass and less frequently with motor deficits. The likelihood of worsened postoperative motor function was decreased in patients with fully resected tumors or preoperative deficits. Recurrence of schwannomas and neurofibromas were seen more frequently in patients diagnosed with NF3 and NF1, respectively. Subtotal resection was associated with the increased recurrence of all benign lesions. CONCLUSIONS Outcomes following resection of benign PNSTs depend on tumor histopathology, tumor location, and genetic predisposition syndrome. Gross-total resection should be attempted for benign lesions where possible. The management of malignant PNSTs remains challenging, requiring a multimodal approach.

High-resolution ultrasonography and shear-wave sonoelastography of a cystic radial nerve Schwannoma

Peripheral nerve tumors are often evaluated with magnetic resonance imaging (MRI), although there are many advantages offered with high-resolution ultrasonography (HRUS). This case report emphasizes the value of HRUS in the diagnosis and management of a patient with a cystic radial nerve Schwannoma. In addition, information on tumor stiffness, obtained with shear-wave sonoelastography (SWE), is presented.

Case Report: Sciatic nerve schwannoma - a rare cause of sciatica

Herein we report a rare case of a sciatic nerve schwannoma causing sciatica in a 69-year-old female. Sciatic nerve schwannoma is a rare entity. It should always be considered as a possible cause of sciatica in patients that present with symptoms of sciatica with no prolapsed disc in the lumbar spine and a negative crossed straight leg raise test. Timely diagnosis and complete excision of the lesion leads to complete resolution of the symptoms of such patients.

Surgical Treatment of Sacral Neurogenic Tumor: A 10-year Experience with 64 Cases

OBJECTIVE

To explore the outcomes of surgical treatment of sacral neurogenic tumors

METHODS

Between 1 January 2003 and 31 December 2012, data on 64 patients with sacral neurogenic tumors treated with surgery were retrospectively analyzed. The mean age of the 64 cases (35 males and 29 females) was 37.2 years (range, 21-69 years); 38 had neurilemmomas and 26 neurofibromas. Thirty-four of the tumors involved S 1 and S 2 , 11 S 3 or lower, and 19 were single presacral soft tissue masses. Tumors were removed via anterior, posterior or combined anteroposterior approaches. Patients with unstable sacroiliac joints underwent iliolumbar fixation.

RESULTS

Depending on the extent of tumor involvement, one of three surgical approaches was used: a single anterior approach (19 patients), single posterior approach (25 patients), or a combined anteroposterior approach (20 patients). The mean operation time was 3 h (range, 2-6 h) and the mean blood loss 878 mL (range, 400-3120 mL). The mean duration of follow-up was 58.2 months (range, 24-93 months). These surgeries had the following complications. Three patients had massive intraoperative hemorrhage and posterior back pain and discomfort postoperatively. One patient had intraoperative ureteral injuries requiring intraoperative ureteral catheterization. In two patients, the tumor involved the S 1 nerve roots bilaterally, necessitating their removal, which resulted in obvious lower limb motion and sphincteric dysfunction. In 13 patients with unilateral tumor involvement of the nerve roots of S 1 and lower spinal levels, only the contralateral nerve roots of the S1 and lower levels were preserved; eight of these patients had impaired bladder and bowel function. Posterior incisions failed to heal in 10 patients, secondary wound healing occurred in nine of them and one required a gluteus maximus myocutaneous flap. Three patients developed postoperative cerebrospinal fluid leaks that were and alleviated by waist belt compression bandaging and placing them in the Trendelenburg position. Eight patients developed tumor recurrences postoperatively; pathological examination of the tissue excised in the second surgeries revealed malignant changes in the three patients with neurilemmomas. There were no intraoperative deaths. Rod fractures occurred in three of the 18 patients requiring iliolumbar reconstruction.

CONCLUSIONS

The clinical characteristics of sacral neurogenic tumors make them easy to diagnose. The approach to resection should be determined by the location and size of the tumor. Patients with huge tumors may lose considerable blood intraoperatively and a have higher risk rate of postoperative complications.

Peripheral Nerve Schwannoma: A Review of Varying Clinical Presentations and Imaging Findings

A schwannoma or neurilemmoma is a benign, isolated, noninvasive, and encapsulated tumor originating from Schwann cells of the peripheral nerve sheath. The incidence of a schwannoma occurring in the foot and ankle is rare, with prevalence rate of 1% to 10%. Schwannomas have no sex predilection, and they commonly occur in patients in their fourth decade. Malignant transformation of benign schwannoma is unusual; however, it is important to note that malignant variants of schwannomas do exist and account for about 5% to 10% of all soft tissue sarcomas. We present 3 cases of benign schwannoma in the lower extremity. All 3 patients presented with varying clinical symptoms, including pain, paresthesia, weakness, and a palpable mass. A schwannoma was eventually diagnosed in all 3 patients. We discuss and review the known entities of peripheral nerve schwannoma and describe the clinical and imaging findings and therapeutic strategies for treating and diagnosing peripheral nerve schwannoma.

Large Cervical Vagus Nerve Tumor in a Patient with Neurofibromatosis Type 1 Treated with Gross Total Resection: Case Report and Review of the Literature

Neurofibromas are benign peripheral nerve sheath tumors that occur commonly in individuals with neurocutaneous disorders such as neurofibromatosis type 1. Vagal nerve neurofibromas, however, are a relatively rare occurrence. We present the case of a 22-year-old man with neurofibromatosis type 1 with a neurofibroma of the left cervical vagal nerve. The mass was resected through an anterior approach without major event. In the postoperative course, the patient developed left vocal cord paralysis treated with medialization with injectable gel. We then present a comprehensive review of the literature for surgical resection of vagal nerve neurofibromas.

Transischiorectal fossa approach for resection of pudendal nerve schwannoma: case report

Pudendal nerve schwannomas are very rare, with only two cases reported in the English-language literature. The surgical approaches described in these two case reports are the transgluteal approach and the laparoscopic approach. The authors present the case of a patient with progressive pelvic pain radiating ipsilaterally into her groin, vagina, and rectum, who was subsequently found to have a pudendal schwannoma. The authors used a transischiorectal fossa approach and intraoperative electrophysiological monitoring and successfully excised the tumor. This approach has the advantage of direct access to Alcock's canal with minimal disruption of the pelvic muscles and ligaments. The patient experienced complete relief of her pelvic pain after the procedure.

Tumors of the peripheral nervous system: analysis of prognostic factors in a series with long-term follow-up and review of the literature

OBJECT

Only a few published studies of the surgical treatment of benign peripheral nerve sheath tumors (BPNSTs), malignant peripheral nerve sheath tumors (MPNSTs), and peripheral non–neural sheath tumors (PNNSTs) have analyzed the results and possible prognostic factors using multivariate analysis. The authors report on their surgical series of cases of BPNSTs, MPNSTs, and PNNSTs with long-term follow-up and analyze the role of selected factors with respect to the prognosis and risk of recurrence of these tumors using multivariate analysis. They also review the pertinent literature and discuss their results in its context.

METHODS

The authors retrospectively reviewed data from cases involving patients who underwent resection of a peripheral nerve tumor between January 1983 and December 2013 at their institution. Of a total of 200 patients, 150 patients (with 173 surgically treated tumors) had adequate follow-up data available for analysis. Pain was assessed using a visual analog scale (VAS), and motor and sensory function were assessed by means of the Louisiana State University grading system. They also analyzed the relationship between tumor recurrence and patient sex, patient age, diagnosis of neurofibromatosis (NF), tumor histopathology, tumor size, tumor location, and extent of resection (subtotal vs gross-total resection), using univariate and multivariate analyses.

RESULTS

There was a statistically significant improvement in the mean VAS pain score (preoperative 3.96 ± 2.41 vs postoperative 0.95 ± 1.6, p = 0.0001). Motor strength and sensory function were significantly improved after resection of tumors involving the brachial plexus (p = 0.0457 and p = 0.0043, respectively), tumors involving the upper limb (p = 0.0016 and p = 0.0016, respectively), BPNSTs (p = 0.0011 and p < 0.0001, respectively), and tumors with dimensions less than 5 cm (motor strength: p = 0.0187 and p = 0.0021 for ≤ 3 cm and 3–5 cm tumors, respectively; sensory function: p = 0.0003 and p = 0.0001 for ≤ 3 cm and 3–5 cm tumors, respectively). Sensory function showed a statistically significant improvement also in patients who had undergone resection of tumors involving the lower limb (p = 0.0118). Total resection was associated with statistically significant improvement of motor strength (p = 0.0251) and sensory function (p < 0.0001). In univariate analysis, a history of NF (p = 0.0034), a diagnosis of MPNST or PNNST (p < 0.0001), and subtotal resection (p = 0.0042) were associated with higher risk of tumor recurrence. In multivariate analysis (logistic regression analysis), a history of NF (OR 9.28%, 95% CI 1.62–52.94, p = 0.0121) and a diagnosis of MPNST (OR 0.03%, 95% CI 0.002–0.429, p = 0.0098) or PNNST (OR 0.081%, 95% CI 0.013–0.509, p = 0.0077) emerged as independent prognostic factors for tumor recurrence.

CONCLUSIONS

A total resection should be attempted in all cases of peripheral nervous system tumors (irrespective of the supposed diagnosis and tumor dimensions) because it is associated with better prognosis in term of functional outcome and overall survival. Moreover, a total resection predicts a lower risk of tumor recurrence. Patients with a history of NF and tumors with malignant histology remain a challenge both for neurosurgeons and oncologists due to higher recurrence rates and the lack of standardized adjuvant therapies.

Primary Brachial Plexus Tumors: Clinical Experiences of 143 Cases

OBJECTIVE

Primary brachial plexus tumors are extremely rare and the treatment is challengeable. Our aim is to share the experiences in the treatment of primary brachial plexus tumors.

METHODS

A retrospective analysis of 143 patients with primary brachial plexus tumors was made in our department from January 2001 to December 2012. The clinical presentation of the patients, the characteristics and pathological results of the tumors and the prognosis were described.

RESULTS

Seventy-eight males and sixty-five female were enrolled. The mean age was 48.17 years old. A palpable mass was the most common clinical presentation occurred in 129 patients. The trunks of the brachial plexus were the locations where the tumors originated with high possibility, with 68 cases. Benign tumors were composed of 119 schwannomas and 12 neurofibromas, while malignant tumors were composed of 8 malignant peripheral nerve sheath tumors, 2 malignant granular cell tumors, 1 synovial sarcoma and 1 peripheral primitive neuroectodermal tumor. Appropriate surgical method, radiotherapy and chemotherapy were used according to the condition during operation, preoperative examinations and pathological result. The survival rate was 50.00% with a 3-year follow-up. Local recurrence happened in 7 patients. Five patients presented Metastasis.

CONCLUSIONS

Appropriate surgical method is the key for the treatment of different brachial plexus tumors. Surgery has a great effect on the treatment of benign tumors. For malignant tumors, adjuvant radiotherapy or chemotherapy should be used according to the pathological result. The general prognosis for malignant brachial plexus tumors is less than ideal.

Malignant peripheral nerve sheath tumor with extensive osteosarcomatous and chondrosarcomatous differentiation: A case report

BACKGROUND

Malignant peripheral nerve sheath tumor is an uncommon tumor of the peripheral nerves. The commonest presenting symptom is soft tissue mass and pain with local neurological findings. Imaging modalities are unhelpful in making a reliable diagnosis. Treatment is radical resection with adequate clear resection margins. Radiotherapy improves the local control, but the prognosis remains poor especially in those with divergent differentiation.

SUMMARY

A 23-year-old man with no history of neurofibromatosis presented with a swelling on the back which has been gradually increasing in size and causing him discomfort. The tumor was surgically excised and the histopathological examination revealed malignant peripheral nerve sheath tumor with extensive osseous and cartilaginous differentiation. He developed pulmonary metastases one year after the surgical resection. Pulmonary metastatectomy was therefore performed and the histopathology of the metastatectomy specimen revealed metastatic malignant peripheral nerve sheath tumor, but without any osseous or cartilaginous differentiation. He remained well with no recurrence or metastases at 9-month follow-up.

CONCLUSION

Malignant peripheral nerve sheath tumor is a malignant tumor that behaves aggressively despite adequate radical resection. This case also illustrates extensive osseous and cartilaginous divergent differentiation of the primary tumor which was surprisingly absent in the metastatic lesions. This finding warrants further research.

Massive exophytic malignant peripheral nerve sheath tumor

We present a case of a solitary neurofibroma involving the right posterior shoulder of a 69-year-old man with degeneration into a massive, malignant peripheral nerve sheath tumor measuring more than 3 times the average reported size. The radiographic, magnetic resonance imaging, and computed tomographic features are compared with the gross appearance and pathology.

Second primary malignant peripheral nerve sheath tumor of the paranasal sinuses after nasopharynx carcinoma

Malignant peripheral nerve sheath tumors are uncommon neoplasms that arise out of Schwann cells from the peripheral nerves, which rarely occur in the paranasal sinuses and nasal cavity. Especially with the increasing long-term survival of patients with nasopharynx carcinoma, second primary cancers can be diagnosed. Second primary cancers are not uncommon in patients with the prior radiation therapy. However, malignant peripheral nerve sheath tumor in the head and neck region after radiation is an exceedingly rare condition. We report the first case of malignant peripheral nerve sheath tumor of the paranasal sinuses as a second primary malignancy in a patient treated with radiation therapy for nasopharyngeal carcinoma 10 years ago.

Visualization of nerve fibers and their relationship to peripheral nerve tumors by diffusion tensor imaging

OBJECT

The majority of growing and/or symptomatic peripheral nerve tumors are schwannomas and neurofibromas. They are almost always benign and can usually be resected while minimizing motor and sensory deficits if approached with the proper expertise and techniques. Intraoperative electrophysiological stimulation and recording techniques allow the surgeon to map the surface of the tumor in an effort to identify and thus avoid damaging functioning nerve fibers. Recently, MR diffusion tensor imaging (DTI) techniques have permitted the visualization of axons, because of their anisotropic properties, in peripheral nerves. The object of this study was to compare the distribution of nerve fibers as revealed by direct electrical stimulation with that seen on preoperative MR DTI.

METHODS

The authors conducted a retrospective chart review of patients with a peripheral nerve or nerve root tumor between March 2012 and January 2014. Diffusion tensor imaging and intraoperative data had been prospectively collected for patients with peripheral nerve tumors that were resected. Preoperative identification of the nerve fiber location in relation to the nerve tumor surface as seen on DTI studies was compared with the nerve fiber’s intraoperative localization using electrophysiological stimulation and recordings.

RESULTS

In 23 patients eligible for study there was good correlation between nerve fiber location on DTI and its anatomical location seen intraoperatively. Diffusion tensor imaging demonstrated the relationship of nerve fibers relative to the tumor with 95.7% sensitivity, 66.7% specificity, 75% positive predictive value, and 93.8% negative predictive value.

CONCLUSIONS

Preoperative DTI techniques are useful in helping the peripheral nerve surgeon to both determine the risks involved in resecting a nerve tumor and plan the safest surgical approach.

Diffusion tensor tractography for the surgical management of peripheral nerve sheath tumors

OBJECT

Peripheral nerve sheath tumors (PNSTs) are uncommon but bear a significant risk of malignancy. High-resolution MRI is the standard technique for characterizing PNSTs. However, planning the appropriate extent of resection and subsequent reconstructive strategies is highly dependent on the intraoperative findings because preoperative MRI evaluation can be insufficient. Diffusion tensor tractography (DTT) represents a recently developed advanced MRI technique that reveals the microstructure of tissues based on monitoring the random movement of water molecules. DTT has the potential to provide diagnostic insights beyond conventional MRI techniques due to its mapping of specific fibrillar nerve structures. Here, DTT was applied to evaluate PNSTs and to examine the usefulness of this method for the correct delineation of tumor and healthy nerve tissue and the value of this information in the preoperative planning of surgical interventions.

METHODS

In this prospective study, patients with the clinical symptoms of a PNST were investigated using DTT 3-Tesla MRI scans. Image data processing and tractography were performed using the FACT (fiber assessment by continuous tracking) algorithm and multiple-regions-of-interest approach. The surgical findings were then compared with the results of the DTT MRI scans. Preoperative fascicle visualization and the correlation with the intraoperative findings were graded.

RESULTS

In a 21-month period, 12 patients with PNSTs were investigated (7 female and 5 male patients with a mean age of 46.2 ± 19.2 years). All patients underwent surgical removal of the tumor. Schwannoma was the most common benign histopathological finding (n = 7), whereas 2 malignant lesions were detected. In 10 of 12 patients, good preoperative nerve fascicle visualization was achieved using DTT scans. In 9 of 10 patients with good preoperative fascicle visualization, good intraoperative correlation between the DTT scans and surgical anatomy was found.

CONCLUSIONS

DTT properly visualizes the peripheral nerve fascicles and their correct anatomical relation to PNST. DTT represents a promising new method for the preinterventional planning of nerve tumor resection.

Accuracy and complications of CT-guided core needle biopsy of peripheral nerve sheath tumours

OBJECTIVE

This single-centre study retrospectively reviews the complications in patients that have occurred following peripheral nerve sheath tumour biopsy, and assesses whether there is an association with biopsy technique or underlying lesion characteristics.

MATERIALS AND METHODS

41 consecutive core needle biopsies of proven peripheral nerve sheath tumours over a 2-year period in a tertiary teaching hospital were reviewed. Patient demographics and symptoms, tumour characteristics and radiological appearances were recorded. Biopsy and surgical histology were correlated, and post-biopsy and surgical complications analyzed.

RESULTS

41 biopsies were performed in 38 patients. 68% schwannomas, 24% neurofibromas and 7% malignant peripheral nerve sheath tumours. Biopsy histology correlated with surgery in all cases. 71% of lesions were surgically excised. 60% of patients reported pain related to their lesion. Following the biopsy, 12% reported increased pain, which resolved in all cases. Pain exacerbation was noted in tumours smaller in size, more superficial and in closer proximity of the biopsy needle tip to the traversing nerve. Number of biopsy needle passes was not associated with an increased incidence of procedure-related pain.

CONCLUSION

Core biopsy of a suspected peripheral nerve sheath tumour may be performed safely before excisional surgery to confirm lesion histology and assist prognosis. There is excellent correlation between core biopsy and excised surgical specimen histology. The most common complication of pain exacerbation is seen in a minority and is temporary, and more likely with smaller, more superficial lesions and a closer needle-tip to traversing nerve distance during biopsy.

Schwannomas of the upper extremity: analysis of 34 cases

BACKGROUND

Schwannomas are the most common benign tumours developing in peripheral nerves. They usually present as a slow-growing mass, sometimes associated with pain and paraesthesia. The aim of this study is to define the correct preoperative diagnosis, to review the surgical treatment employed and to evaluate short- and long-term neurological deficits.

METHODS

Thirty-four patients affected by schwannoma in the upper limbs were treated in the period 1995-2011. In 15 patients the tumour was located on the ulnar nerve, in 8 on the median nerve, in 2 on the radial nerve, in 1 on the anterior interosseous nerve, in 1 on the muscle-cutaneous nerve, and in the remaining 7 on the digital nerves. All patients were surgically treated using a microsurgical approach.

RESULTS

The enucleation of the mass was possible without fascicle lesion in 12 cases. In 22 cases resection of the indissociable fascicles was performed. Postoperative paraesthesia was present in 28 out of 34 treated patients; this clinical sign regressed in a mean period of 12 months in 27 patients.

CONCLUSIONS

When approaching a palpable mass in the upper limbs, the possibility of a peripheral nerve tumour should always be considered. It is important to look for typical signs of schwannomas, such as a positive Tinel sign and peripheral paraesthesia. Imaging assessment with magnetic resonance imaging (MRI) and ultrasonography enables the determination of where the tumour takes its origin and from which nerve. Microsurgical techniques and know-how are recommended in approaching the resection in order to respect as many nerve fibres as possible.

Radiation-induced intradural malignant peripheral nerve sheath tumor of the cauda equina with diffuse leptomeningeal metastasis

Malignant peripheral nerve sheath tumors (MPNSTs) are rare, affecting only a small portion of the general population. In many cases, MPNSTs occur in association with neurofibromatosis Type 1 and at times arise secondary to previous radiation therapy (RT). These tumors can be found essentially anywhere a peripheral nerve is present, but they rarely originate primarily from the spinal nerve or cauda equina and cause leptomeningeal spread. This report describes the treatment course of a 43-year-old man with a history of testicular seminoma treated with RT a decade before, who was found to have a large sacral MPNST. The patient underwent complete sacrectomy for gross-total resection. Despite this effort, he was eventually found to have metastatic lesions throughout the spine and brain, ultimately resulting in acute hydrocephalus and death. Biopsy results of these metastatic lesions proved to be characteristic of his original MPNST. The literature is also reviewed and the diagnostic modalities, management strategies, and prognosis of MPNST are discussed.

Is surgery for brachial plexus schwannomas safe and effective?

BACKGROUND

Schwannomas rarely are found in the brachial plexus, and although they are benign, they present significant challenges to surgical treatment. To our knowledge, there are few studies investigating the surgical outcomes of patients with brachial plexus tumors.

QUESTIONS/PURPOSES

We analyzed the outcomes of 19 patients with brachial plexus schwannomas and asked: (1) How do these patients present? (2) Where are the tumors located in the brachial plexus? (3) What are the complications and neurologic results of patients after excision of the tumor?

METHODS

From February 2002 to August 2012, one orthopaedic hand surgeon treated 19 patients with schwannomas of the brachial plexus. We retrospectively reviewed the medical records and MRI data of all patients. There were 11 women and eight men, with a mean age of 50.2 years (range, 32-63 years). The tumor was located on the right side in eight patients and on the left in 11 patients. We evaluated neurologic deficits preoperatively and neurologic deficits and local recurrence of tumors postoperatively. Minimum followup was 12 months (mean, 37.2 months; range, 12-90 months).

RESULTS

The most common initial presentation was a palpable mass. The masses were located at all levels along the brachial plexus, including the root, trunk, cord, and terminal branches. The smallest mass was 1.5 × 1.5 × 0.5 cm and the largest was 11 × 10 × 6 cm. Fourteen of the 19 patients did not have any postoperative neurologic deficits. All the removed masses were proven histologically to be schwannomas. Of the five patients who had postoperative neurologic deficits, three had transient sensory deficits, one had weakness of the flexor pollicis longus and second flexor digitorum profundus, and another had weakness of the extensor pollicis longus. No recurrence was observed during the followup period.

CONCLUSIONS

Schwannomas of the brachial plexus are a potentially curable lesion with an acceptable surgical risk of injury to neurovascular structures. With precise surgical techniques, these tumors can be removed to improve symptoms with minimal morbidity.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Isolated schwannoma attached to the paratenon of semitendinosus muscle

Schwannomas are benign tumors arising from the peripheral nerves with a Schwann cell sheath. Schwannomas can be found in almost every region, but are usually associated with cranial, spinal, sympathetic and peripheral nerves. Schwannoma in lower extremity is relatively common and most are associated with sciatic nerve, peroneal nerve and tibial nerve. However, schwannoma arising in the tendon or paratenon is extremely rare. We report a rare case of a 25-year-old male patient with a schwannoma originating from the paratenon of semitendinosus muscle without evidences of any neurologic symptoms. The clinical history, plain radiographs, magnetic resonance imaging, and pathologic findings of the reported patient have been reviewed. The tumor was fully excised by dissecting a tendon sheath of semitendinosus muscle.

"Huge axillary mass - neurofibroma brachial plexus"

Axillary swelling arising from soft tissue is not uncommon. Lipoma, Lymphadenopathy due to Kochs or Lymphoma are commonest swellings seen but firm to hard non tender mass arising from maninges of Brachial plexus is not so common. Usually these masses are benign but one may come across malignant tumour. Twenty-three year male presented with mass in anterior chest wall & arm pit having no other specific complaints, was diagnosed as Spindle cell tumour on FNAC & excision biopsy turned out to be Neurofibroma of Brachial plexus.

Sporadic Multifocal Malignant Peripheral Nerve Sheath Tumor-A Rare Presentation: Multifocal MPNST

Malignant peripheral nerve sheath tumors(MPNST) are uncommon neoplasms with an incidence of 0.001% in general population. Multifocality is a rare manifestation of MPNST . A case of a 65 year old patient who presented with multiple swellings involving the neck, extremity and back without associated neurofibromatosis is reported for its rarity of presentation.. Diagnosis was made by FNAC and confirmed by peroperative findings and histopathology.

Solitary schwannoma of the sural nerve: An unusual clinical presentation

Schwannomas may arise from any peripheral nerve containing Schwann cells. However, sural nerve schwannoma is extremely rare. In this study, a case of solitary schwannoma originating from the sural nerve in a 42-year-old male is presented. Physical examination revealed a 3-cm, elastic-hard, mobile, non-tender mass, while neurovascular examinations, including Tinel's sign, were normal. Magnetic resonance imaging revealed an oval-shaped subcutaneous mass with iso-signal intensity relative to skeletal muscle on T1-weighted sequences. T2-weighted spectral presaturation with inversion recovery sequences showed higher signal intensity peripherally and lower signal intensity centrally, representing a target sign. Contrast-enhanced T1-weighted sequences demonstrated a marked central enhancement of the mass. The tumor was completely enucleated using an intracapsular technique. Histological examination confirmed the diagnosis of a schwannoma, consisting mainly of Antoni A tissue. The patient had no evidence of local recurrence and no neurological deficit at the final follow-up. Although rare, schwannoma should be considered in the differential diagnosis of a well-defined, oval, subcutaneous mass in the posterior aspect of the lower leg.

Malignant Peripheral Nerve Sheath Tumour: CT and MRI Findings

Malignant peripheral nerve sheath tumour (MPNST) is extremely rare malignancy in the general population, occurring more frequently in patients with Neurofibromatosis type 1 (NF1). In the literature five cases of MPNST arising from the parapharyngeal space (PPS) in patients without neurofibromatosis have been reported. We report imaging techniques in a patient with MPNST in the PPS, who had neither a family history nor sign of NF1. Computed tomography (CT) scan and magnetic resonance imaging (MRI) were performed for a correct therapeutic planning. CT and MRI findings were correlated with hystopathological diagnosis.

Brachial plexus reconstruction following resection of a malignant peripheral nerve sheath tumor: case report

BACKGROUND AND IMPORTANCE

The main therapeutic approach for malignant peripheral nerve sheath tumors (MPNSTs) of the brachial plexus is wide local excision. Sacrifice of some--occasionally all--elements of the brachial plexus often is required to obtain complete resection, and therefore can be associated with significant morbidity. While peripheral nerve repair is commonly used in the setting of traumatic nerve injury, little is known about its potential use in the treatment of MPNST.

CLINICAL PRESENTATION

We present a patient with an enlarging right neck mass who was diagnosed with MPNST of the brachial plexus. The patient underwent gross total resection of the tumor, requiring sectioning of the upper trunk of the brachial plexus, as well as associated divisions. Following resection, sural nerve grafts were used to connect the C5 nerve root to the anterior division of the upper trunk and the spinal accessory nerve to the suprascapular nerve, whereas a triceps branch of the radial nerve was coapted directly to the anterior division of the axillary nerve.

CONCLUSION

By 20 months after surgery, the patient had regained significant strength in her upper trunk distribution and demonstrated no evidence of tumor recurrence. Brachial plexus reconstruction offers a potentially valuable surgical adjunct to MPNST treatment.

Renal carcinoma relapse presenting as a peripheral nerve sheath tumor: A case report and brief review of the literature

We report a rare case of renal carcinoma metastasis involving a lumbar nerve root. Metastases to nerve roots are rare occurrences, and to our knowledge, only six cases have been reported so far in the literature. The patient in this report presented with weakness in the right lower limb and intractable pain irradiating along the L5 dermatome. MRI findings revealed a right-sided L5 nerve root mass, suggestive of a schwannoma, involving the spinal ganglion and its extraforaminal region. Complete macroscopic resection of this mass was performed, and histopathologic analysis confirmed the lesion to be a metastasis of a renal clear cell carcinoma. Local radiotherapy was given and tyrosine kinase inhibitors administered. At 5 months, the patient was pain-free and his right limb weakness had completely resolved. A tumoral recurrence could be observed on the control MRI 5 months after surgery. This report presents the first case of a patient with a renal clear cell carcinoma metastasis to a L5 nerve root, as well as a brief review of previous cases of metastases to peripheral nerve roots.

Ancient schwannoma involving the median nerve: a case report and review of the literature

Ancient schwannomas are benign long standing schwannomas of the neural sheaths. Histological findings are these seen as in conventional schwannomas, but ancient schwannomas additionally demonstrate cystic hemorrhagic changes and degenerative nuclei with pleomorphism and hyperchromasia. Due to the nuclear atypia, and cystic degeneration, ancient schwannomas might be confused with malignant tumors on histology and imaging, leading to a radical surgical approach. The median nerve is rarely affected. We present a rare case of an ancient schwannoma involving the median nerve at the mid humerus. The tumor slowly grew up within ten years and become symptomatic with local pain, mild numbness in the distribution of the median nerve in the palm and Tinel's test. The tumor was successfully removed by separating it from the nerve fascicles to negative margins. Post-operatively local symptoms relieved but minor sensory loss in the median nerve distribution in the palm was noticed which improved in the following six months. Ancient schwannomas can be misdiagnosed as sarcomas due to specific imaging and histologic findings. Patients' physical examination, history and fine radiologic and pathology features should be cautiously interpreted in order to achieve correct diagnosis and avoid unnecessary wide tumor excisions.

[Schwannoma of the femoral nerve: a rare differential diagnosis of leg pain]

BACKGROUND

Schwannomas (neurinomas) are among the most frequent peripheral nerve tumors. Nevertheless, these are seldom located in the lower extremities in association with the femoral nerve.

CLINICAL PRESENTATION

In this case, the occurrence of a schwannoma adjacent to the femoral nerve is described in a patient presenting with nonspecific pain in the thigh accompanied by a palpable mass. Sensory and motor deficits were not present. Further examinations by MRI and biopsy followed by histopathology, revealed the diagnosis of a schwannoma. The tumor was completely excised.

CONCLUSION

Although schwannomas of the lower extremities are rare, they should be included in the differential diagnosis. Knowing the typical clinical symptoms, radiological signs, and histopathological findings, diagnosis should be straight forward.

Management of desmoid-type fibromatosis involving peripheral nerves

Desmoid-type fibromatosis is an uncommon and aggressive neoplasia, associated with a high rate of recurrence. It is characterized by an infiltrative but benign fibroblastic proliferation occurring within the deep soft tissues. There is no consensus about the treatment of those tumors. We present a surgical series of four cases, involving the brachial plexus (two cases), the median nerve and the medial brachial cutaneous nerve. Except for the last case, they were submitted to multiple surgical procedures and showed repeated recurrences. The diagnosis, the different ways of treatment and the prognosis of these tumoral lesions are discussed. Our results support the indication of radical surgery followed by radiotherapy as probably one of the best ways to treat those controversial lesions.

Radiographic association of schwannomas with sensory ganglia

OBJECTIVE

Clinical experience suggests that the majority of schwannomas arise within sensory ganglia, suggesting that intraganglionic glial cells represent a potential cell of origin for schwannomas. To support this clinical impression, we reviewed magnetic resonance imaging (MRI) studies performed over a 5-year period at our institution to determine the relationship of cranial and spinal nerve schwannomas with the ganglia of the associated nerves.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary referral center.

PATIENTS

Patients undergoing imaging study at our institution over a 5-year period.

INTERVENTION(S)

Radiographic images at our institution were reviewed as well as published studies to determine the anatomic location of schwannomas.

MAIN OUTCOME MEASURE(S)

Anatomic location of schwannomas.

RESULTS

A total of 372 patients were found over the 5-year study period, 31 of those were diagnosed with neurofibromatosis Type 2 (NF2). Vestibular schwannomas comprised the greatest number of schwannomas, followed by spinal schwannomas. In NF2 patients, spinal schwannomas were the most common tumor, followed by vestibular schwannomas. In NF2 patients and those with sporadic schwannomas, the overwhelming majority of tumors arose in nerves with a sensory component and were associated with the sensory ganglia of the nerves (562/607, 92.6%). Very few tumors arose from pure motor nerves. This is supported by review of published articles on anatomic location of schwannomas.

CONCLUSION

Schwannomas are strongly associated anatomically with the ganglia of sensory nerves. These findings raise the possibility that intraganglionic glial cells give rise to the majority of schwannomas.

Granular cell tumor of brachial plexus mimicking nerve sheath tumor: a case report

Primary tumors of the brachial plexus region are rare and granular cell tumors arising from the brachial plexus region is an extremely rare disease. We present a case of granular cell tumor arising from of the brachial plexus which appeared to be a usual presentation of nerve sheath tumor before the pathological confirmation. We report a granular cell tumor of the brachial plexus with literature review. Total resection is important for good clinical outcome and prognosis in the treatment of granular cell tumor.

Brachial plexus tumors in a consecutive series of twenty one patients

Objective

This is a retrospective review of 22 surgically treated benign and malignant tumors of brachial plexus region to describe clinical presentation, the characteristics of brachial plexus tumor and clinical outcomes with a literature review.

Methods

Twenty-one patients with consecutive 22 surgeries for primary brachial plexus tumors were enrolled between February 2002 and November 2011 were included in this study. The medical records of all patients were reviewed.

Results

Eleven male and 10 female patients were enrolled. Mean age was 39 years. Three patients had brachial plexus tumor associated with neurofibromatosis (13.6%). Presenting signs and symptoms included parenthesis and numbness (54.5%), radiating pain (22.7%), direct tenderness and pain (27.2%), palpable mass (77.3%). Twelve patients presented preoperative sensory deficit (54.5%) and 9 patients presented preoperative motor deficit (40.9%). Twenty tumors (90.9%) were benign and 2 tumors (9.1%) were malignant. Benign tumors included 15 schwannomas (68.2%), 4 neurofibromas (18.2%) and 1 granular cell tumor (4.5%). There were 1 malignant peripheral nerve sheath tumor (MPNST) and 1 malignant granular cell tumor. Gross total resection was achieved in 16 patients (72.7%), including all schwannomas, 1 neurofibroma. Subtotal resection was performed in 6 tumors (27.3%), including 3 neurofibromatosis associated with brachial plexus neurofibromas, 1 MPNST and 2 granular cell tumor in one patient.

Conclusion

Resection of tumor is the choice of tumor in the most of benign and malignant brachial plexus tumors. Postoperative outcomes are related to grade of resection at surgery and pathological features of tumor.