Neurological deficit after surgical enucleation of schwannomas of the upper limb

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.

Limb schwannoma: Factors for postoperative neurologic deficit and poor functional results

INTRODUCTION

Neurologic complications after limb schwannoma resection are not unusual, but there is no consensus on risk factors for neurologic deficit or poor functional results. We therefore conducted a retrospective study, to screen for factors predicting, firstly, postoperative neurologic deficit and, secondly, poor functional results.

HYPOTHESIS

Certain pre- and intraoperative features predict risk of failure, poor results or aggravation.

PATIENTS AND METHODS

A single-center retrospective study was conducted in the University Hospital of Lille, France, for the period January 2004 to March 2020, including 71 patients. Preoperative variables (gender, age, symptoms, progression, tumor location and size) and operative data (type of surgery) were collected as possible risk factors for postoperative sensory deficit (Weber) and/or motor deficit [Medical Research Council (MRC)] and poor functional result [Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH); Lower Extremity Functional Scale (LEFS) and douleur neuropathique (neuropathic pain) 4 (DN4)].

RESULTS

Results were assessed a mean 69.4±38.5 months' follow-up (range, 6-180 months). In total, 21 patients (29.6%) had deficits (21 sensory, 1 motor) preoperatively and 25 patients (35.2%) postoperatively (20 sensory, 9 motor) (p=0.689). Fourteen patients (19.7%) showed functional aggravation. Fascicular resection was associated with risk of postoperative deficit [OR = 4.65 (95% CI: 1.485-15.543); p=0.004] and functional deterioration [OR = 3.9 (95% CI: 1.143-13.311); p=0.042]. Thirteen patients (18.3%) showed no improvement on DN4. Preoperative pain was a factor for improvement on DN4 [OR = 3.667 (95% CI: 1.055-12.738); p=0.0409].

DISCUSSION

The study identified fascicular resection as a risk factor for postoperative deficit and functional deterioration after limb schwannoma resection. Patients with preoperative neuropathic pain showed alleviation. Resection should be precise, under magnification, avoiding fascicular resection. Preoperative patient information is essential.

LEVEL OF EVIDENCE

IV; retrospective series.

Intracapsular Enucleation of Brachial Plexus Schwannoma With Intraoperative Neuromonitoring: A Case Series Study and a Review of Literature

OBJECTIVE

Brachial plexus schwannoma (BPS) is a rare clinical entity that poses a significant challenge for head and neck surgeons due to its neuroanatomical complexity and potential severe complications, such as major motor or sensory neurological deficits or pain of the corresponding upper extremity. This article summarizes our experience in its diagnosis and intracapsular enucleation with intraoperative neuromonitoring (INM).

METHODS

A retrospective review of BPS cases treated at our tertiary medical institution was conducted between April 2020 and May 2023. The clinical and demographic data were retrieved from case notes.

RESULTS

Totally, 3 cases were included. All 3 patients were male, aged 43 to 54 years (median age = 52). The presenting symptom was a palpable supraclavicular mass in all these cases (2 on the left side and 1 on the right side). Neuromonitoring was performed with a 4-channel nerve integrity monitor, with the electrodes placed in the upper arm and forearm muscles, as demonstrated in the literature. After exposing the mass and identifying its origin from the brachial plexus, a unipolar stimulating probe was used to stimulate the tumor surface or the nerves with a 1.0-mA current, and a longitudinal incision into the tumor capsule was made along a carefully mapped line with no INM response. Then the mass was carefully exposed and meticulously dissected from its capsule to achieve an intact enucleation. Immediate postoperative neurological deficit was documented in Case 1 as a mild grasping weakness. The recovery of the other 2 patients was uneventful. The follow-up duration was 7 to 38 months (median = 8 months). The minor motor deficit of Case 1 recovered completely 1 month after surgery. No recurrence of BPS was observed.

CONCLUSIONS

Intracapsular enucleation with INM could result in complete removal of BPS and minimal postoperative neurological deficit, whose recovery was quick and satisfactory.

Giant schwannoma on the lower leg: A case report and review of the literature

INTRODUCTION AND IMPORTANCE

Peripheral nerve sheath tumors are common neoplasm with different biological features ranging from benign to malignant. The majority of these tumors are smaller than 5 cm, whereas those larger are termed giant schwannomas. When localized in the lower legs, the maximum length of the schwannoma is less than 10 cm. We report a case of giant schwannoma of the leg and its management.

CASE PRESENTATION

A 11-year-old boy presented with a 13 cm × 5 cm firm, smooth, well-defined margin mass in the posterior-medial aspect of right leg. The tumor was fusiform, well capsulated, multi-lobulated soft tissue with 13 cm × 4 cm × 3 cm in size at the biggest region. On MRI the tumor was low signal, isointense with adjacent tissue on T1S, hyper-intense on T2-FS sequences and surrounded by a thin fat-like intense rim. Biopsy findings were considered most consistent with Schwannoma (Antoni A). Tumor resection was performed. The mass appeared capsulated, white, and glistening with 132 mm × 45 mm × 34 mm in size. Postoperative course was uneventful without neurological deficit.

CLINICAL DISCUSSION AND CONCLUSION

Schwannomas are the most common peripheral nerve sheath tumors that derived almost entirely from Schwann cells. Schwannomas usually affect the head and neck region, localization in the lower extremity is rare. When located in lower extremity, the maximum diameter of 5 cm is described in most studies. Clinical presentation of schwannomas is unclear and unspecific. Diagnosis is based on ultrasound, MRI, and histology. The recommended treatment for schwannoma is surgical enucleation or resection without damaging the involved nerve.

Benign nerve tumours in the upper limb: a registry-based study of symptoms and surgical outcome

Surgery for benign nerve tumours is performed for pathoanatomical diagnosis and symptomatic relief, but might cause residual problems. We aimed to assess patient-reported symptoms and disability before and after surgery at a national level. In total, 206 cases surgically treated for a benign peripheral nerve tumour 2010-2019 registered in the Swedish Quality Registry for Hand Surgery (HAKIR; response rates 22-34%) were analysed. Surgery reduced overall disability in the affected limb (QuickDASH 18/100 [IQR 5-36] preoperatively and 5/100 [IQR 0-22] 12 months postoperatively), improved ability to perform daily activities (HQ-8; 11/100 [IQR 0-50] preoperatively and 0/100 [IQR 0-20] 12 months postoperatively) and decreased three evaluated pain modalities: pain at rest (HQ-8; 20/100 [IQR 0-40] preoperatively and 0/100 [IQR 0-10] 12 months postoperatively), pain on motion without load (HQ-8; 20/100 [IQR 0-40] preoperatively and 0/100 [IQR 0-10] 12 months postoperatively), and pain on load (HQ-8; 24/100 [IQR 1-69] preoperatively and 1/100 [IQR 0-30] 12 months postoperatively). Cold sensitivity was a minor problem both before and after surgery (HQ-8; 0/100 [IQR 0-30] preoperatively and 1/100 [IQR 0-40] 12 months postoperatively). We conclude that surgery for benign peripheral nerve tumours provides good symptomatic relief with low risk for residual problems.

Resection of brachial plexus schwannomas while monitoring transcranial motor evoked potentials: report of two cases

A schwannoma is a benign nerve sheath tumor treated by enucleation, which carries the risk of intraoperative nerve injury that is observed after awakening. Transcranial motor evoked potential (TcMEP) monitoring has been established as an effective method to predict and prevent intraoperative neurological complications during brain and spinal surgery. However, there have been few reports on its application in head and neck surgeries. We performed enucleation to relieve the symptoms due to schwannomas in the neck of two women, aged 25 years and 70 years. Both women presented with a left cervical mass, paresthesia of the left upper limb, and a Tinel-like sign without muscle weakness. TcMEPs were recorded before beginning surgery, during surgery, and immediately before completing surgery. The dissecting lines were decided using the stimulator attached to the dissecting instrument, which helped warn the surgeon regarding risky areas. Histopathological examinations confirmed the diagnosis of schwannoma. There was no significant difference in the pre- and postoperative TcMEP recordings, and no postoperative motor deficits were identified. Intraoperative TcMEP monitoring is expected to be useful in preventing operative complications while treating head and neck schwannomas.

Clinical characteristics and management experience of schwannoma in extremities: Lessons learned from a 10-year retrospective study

Introduction

Schwannomas are the most common neoplastic lesions of the peripheral nerves when growing on the extremities, they usually have adverse effects on patients due to the exposed and functional nature of the region.

Methods

In the present single-center retrospective study, we included all patients with pathologically confirmed schwannoma located in extremities between 2011 and 2021 totaling 183 patients. Data on gender, age, duration history, clinical presentation, occurrence region, nerve affiliation, imaging data, modus operation, mass volume, immunohistochemistry, postoperative neurological function, and recurrence were collected.

Results

As in previous studies, patients were predominantly middle-aged with a mean age of 49.5, without gender preference and a male-to-female ratio of 1.2:1. Most patients are first seen for this disease, and only five of them are recurrent. The majority presented with an isolated (91.26%), asymptomatic (37.7%) mass, with tenderness (34.97%) being the second frequent complaint. 60% of lesions occurred in the upper extremity, more commonly on the left side (55.26%) than the right. The average duration of onset was 47.50 months. MRI is more sensitive for neurogenic tumors than ultrasound, as it owns 78.93% correct. In immunohistochemistry, the top three markers for positive labeling schwannoma are S-100 (98.95%), Ki67 (98.68%) and β-Catenin. 98.36% of patients underwent complete resection of the lesion, of which 14.44% required partial sacrifice of the nerve fibers. Thanks to the application of intraoperative peripheral nerve microscopic operation, only 6 patients showed symptoms of postoperative nerve injury, and 3 of them received second surgery. Intraoperative microscopic manipulation, preservation of the main nerve, and the need for reconstruction of the affected nerve fibers are some of the points worth noting.

Discussion

In summary, the possibility of schwannoma should not be overlooked in the identification of masses that occur in the upper extremities of the middle-aged population. Preoperative ultrasound and MR are useful for determining the nature of the mass, and S100, Ki67, and β-Catenin are sensitive to it. Surgical resection can achieve satisfying functional results and a low risk of nerve injury.

Clinical results after surgical resection of benign solitary schwannomas: A review of 150 cases

INTRODUCTION

Peripheral nerve schwannomas are the most common nerve tumors. While they are efficiently treated with surgery, the risk of neurological complications, especially sensory deficits, remains debated.

HYPOTHESIS

We postulate that rates of post-operative sensory deficits in peripheral schwannoma surgery are low and are not increased in schwannomas of the hand, in which preservation of discriminative tact is of prime functional importance.

MATERIALS AND METHODS

A retrospective multicenter study was carried out on 150 patients with an isolated peripheral schwannoma operated between 2002 and 2018, including 11 patients with schwannomas of the hand. All cases were reviewed preoperatively and postoperatively with a detailed exam of the neurological status.

RESULTS

Most schwannomas were located in the lower limbs (58%). The two main affected trunks were the posterior tibial nerve in the lower limb and the median nerve in the upper limb. The average preoperative tumor volume measured on MRI was 2.93 cm³ [0.11 cm³-25 cm³]. The most common preoperative symptoms were paresthesia (77.1%) and pseudo-Tinel sign (55.7%). Less frequently, pain (50.3%) and hypoesthesia (18.1%) were observed. On the other hand, preoperative neurological motor manifestations remained exceptional (3.3%). The rates of new post-operative motor deficits, paresthesias, and sensory deficits were 4.6%, 10.9% and 8% respectively and were not increased in schwannomas of the collateral nerves of the hand.

CONCLUSION

Surgical resection is a safe procedure for peripheral nerve schwannoma treatment with satisfying functional results and an acceptable risk of nerve injury, especially for sensory function.

LEVEL OF PROOF

D; Multicenter retrospective study.

Predicting the Risk of Postoperative Complications of Schwannoma Surgery: Development and Assessment of a New Predictive Nomogram

BACKGROUND

 The aim of this study was to develop and internally validate a risk nomogram for postoperative complications of schwannoma surgery.

METHODS

 From 2016 to 2020, we reviewed 83 patients who underwent schwannoma resection with a total number of 85 schwannomas. A predictive model was developed based on the dataset of this group. During model construction, univariate and multivariate logistic regression analysis were used to determine the independent predictors of postoperative complications. Assessment of the discriminative function, calibrating proficiency, and clinical usefulness of the predicting model was performed using C-index, calibration plot, receiver operating characteristic (ROC) curve, and decision curve analysis. Internal validation was assessed using bootstrapping validation.

RESULTS

 Predictors contained in the prediction nomogram included age, tumor location, symptoms, and surgical approach. The model displayed satisfying abilities of discrimination and calibration, with a C-index of 0.901 (95% confidence [CI]: 0.837-0.965). A high C-index value of 0.853 was achieved in the interval verification. Decision curve analysis showed that the nomogram was clinically useful when intervention was decided at the complication possibility threshold of 2%.

CONCLUSION

 This new risk nomogram for postoperative complications of schwannoma surgery has taken age, tumor location, symptoms, and surgical approach into account. It has reasonable predictive accuracy and can be conveniently used. It shall help patients understand the risk of postoperative complications before surgery, and offer guidance to surgeons in deciding on the surgical approach.

Schwannoma in the extremity: clinical features and microscopic intra-capsular enucleation

Objective: Schwannomas are the most common type of neoplasm of the peripheral nerves. Enucleation is a standard surgical procedure; however, it occasionally results in iatrogenic nerve injury, even with atraumatic procedures. Herein, we present the clinical characteristics of schwannoma arising in the extremities and discuss the clinical outcomes of extra- and intra-capsular enucleation.

Patients and Methods: We reviewed 122 schwannomas treated at our institute. Schwannomas arising from the minor nerve (n=30) or intramuscularly (n=15) were operated using the extra-capsular technique. Of the 77 major nerve schwannomas, 62 schwannomas were treated using the intra-capsular technique and 15 schwannomas using the extra-capsular technique.

Results: Neurological deficits following enucleation were significantly lower using the intra-capsular technique than with the extra-capsular technique. The patient age, duration of symptoms, maximum tumor diameter, and site of occurrence were not associated with subsequent neurological deficits. With both techniques, no tumor recurrence was observed at the final follow-up.

Conclusion: These results support the use of intra-capsular micro-enucleation as a safe and reliable treatment for every type of schwannoma. To minimize the risk of nerve injury, en bloc resection should not be used because the main purpose of schwannoma surgery is the relief of symptoms, not tumor resection.

Clinical outcome after surgery on schwannomas in the extremities

BACKGROUND

Schwannoma is a benign, encapsulated and slowly growing tumor originating from Schwann cells and is rarely seen in the peripheral nerve system. Typical symptoms are soreness, radiating pain and sensory loss combined with a soft tissue mass.

AIM

To evaluate pre- and postoperative symptoms in patients operated for schwannomas in the extremities and investigate the rate of malignant transformation.

METHODS

In this single center retrospective study design, all patients who had surgery for a benign schwannoma in the extremities from May 1997 to January 2018 were included. The location of the tumor in the extremities was divided into five groups; forearm, arm, shoulder, thigh and leg including foot. The locations of the tumor in the nerves were also categorized as either; proximal, distal, minor or major nerve. During the pre- and postoperative clinical evaluation, symptoms were classified as paresthesia, local pain, radiating pain, swelling, impairment of mobility/strength and asymptomatic tumors that were found incidentally (with magnetic resonance imaging). The patients were evaluated after surgery using the following categories: Asymptomatic or symptomatic patients (radiating and/or local pain) and those with complications. The follow up period was from the time of surgery until last examination of the particular physician. Multivariate logistic regression analysis was performed to identify independent prognostic factors for postoperative significant symptoms at follow-up.

RESULTS

We identified 858 cases from the institutional pathology register. We excluded cases with duplicate diagnoses (n = 407), pathology not including schwannomas (n = 157), lesions involving the torso, spine and neck (n = 150) leaving 144 patients for further analysis. In this group 99 patients underwent surgery and there were five complications recorded: 2 infections (treated with antibiotics) and 3 nerve palsies (2 involving the radial nerve and one involving the median nerve) that recovered spontaneously. At the end of follow-up, 1.4 mo (range 0.5-76) postoperatively, we recorded a post-operative decrease in clinical symptoms: Local pain 76% (6/25), radiating pain 97% (2/45), swelling 20% (8/10). Symptoms of paresthesia increased by 2.8% (37/36) and there was no change in motor weakness before and after surgery 1% (1/1). Multivariate analysis showed that tumors located within minor nerves had a significantly higher prevalence of postoperative symptoms compared with tumors in major nerves (odds ratio: 2.63; confidence intervals: 1.22-6.42, P = 0.029). One patient with schwannoma diagnosed by needle biopsy was diagnosed to have malignant transformation diagnosed in the surgically removed tumor. No local recurrences were reported.

CONCLUSION

Surgery of schwannomas can be conducted with low risk of postoperative complications, acceptable decrease in clinical symptoms and risk of malignant transformation is low.

A clinicopathological study of peripheral schwannomas

Aim and objective

Schwannomas are benign neoplasms of neural origin with sporadic or syndromic occurence. They are commonly seen in cranial nerves. Peripheral schwannomas occur rarely and may have unique presentations. The aim of this study is to evaluate the clinico-pathological characteristics of peripheral schwannomas.

Methods

A retrospective cross sectional study of peripheral schwannomas excluding head neck region was conducted. The study group consisted of 18 cases which were recorded over a period of seven years. The corresponding data were collected from the archives of the Department of Pathology.

Results

Male to female ratio was 1:1. The average age of the cases was 47 years. The most common site was the upper limbs (55.55%) followed by lower limbs, chest and penis. The lesions mostly presented as painless swellings (62%). Histopathological examination revealed classic features of schwannoma. Secondary changes included cystic degeneration, foam cells, epitheloid cells, hyalinization, microcystic change and collection of plasma cells. All cases were confirmed by positive S100 staining.

Conclusion

Peripheral schwannomas may be missed due to its rarity and atypical presentations. Both clinicians and pathologists should be aware of this common entity at unusual sites for the proper management of the patients. Surgery is usually the treatment of choice.

Retrospective Analysis of 20 Patients Affected by Schwannomas in the Upper and Lower Limbs

Objective  To analyze the epidemiological profile and evolution of 20 patients diagnosed with upper- and lower-limb schwannomas.

Methods  A group of patients was defined for a retrospective evaluation comprising the period between February 2002 and June 2018, in which we studied and evaluated 20 medical records of patients undergoing surgery due to schwannoma; the diagnosis was confirmed by an anatomopathological examination.

Results  Male and female patients were equally affected. The average age was 50.85 years, ranging from 12 to 77 years. There was a predominance of the upper limb and of the flexor face. The most affected nerve was the ulnar nerve. In total, 6 (30%) patients had transient postoperative complications. No cases of tumor recurrence were identified.

Conclusion  Schwannoma is a rare and difficult-to-diagnose lesion. It should always be considered as a hypothesis when facing a soft-tissue tumor affecting the limbs. The Tinel sign should be regarded, given its higher correlation with complications. The patients should be informed of the possible postoperative complications, which are frequent but usually transient.

Feasibility of Brachial Plexus Schwannoma Enucleation With Intraoperative Neuromonitoring

Objectives

To evaluate the feasibility of brachial plexus schwannoma enucleation under intraoperative neuromonitoring.

Methods

Five patients who were treated for brachial plexus schwannoma under intraoperative neuromonitoring from 2008 to 2018 were included in this retrospective review. Neuromonitoring was performed with a 100-μV event threshold of the neuromonitoring system (NIM-2 or 3) at the deltoid, biceps brachii, triceps brachii, and brachioradialis muscles. Patient characteristics, tumor size and location, intraoperative neuromonitoring findings, and postoperative function were evaluated.

Results

The intraoperative neuromonitoring findings were in accordance with the preoperative assessment of the included nerve root. Three patients had no postoperative morbidity, one patient had temporary paresthesia of the forearm for 2 months, and one patient mild loss of grip strength for 1 month.

Conclusion

Intraoperative neuromonitoring of the arm and forearm muscles during enucleation of brachial plexus schwannoma promoted confident and successful surgery with minimal postoperative morbidity.

Predictive factors of postoperative deficit and functional outcome after surgery for upper limb schwannomas: Retrospective study of 21 patients

Schwannomas are the most frequent benign tumors of the peripheral nerves. Tumor enucleation is the traditional surgical treatment. The incidence of neurological complications after surgery varies and predictive factors for these complications are not clearly defined. The aim of this study was to find predictive factors of postoperative neurological deficit after surgical treatment of schwannomas of the upper limb. Twenty-four schwannomas removed from 21 patients were analyzed retrospectively. The patients' mean age was 45.4years and the mean follow-up was 64.4months. Clinical parameters studied were age, gender, nature of preoperative symptoms, duration of symptoms, type of surgery performed, tumor location and size, nerve involved, QuickDASH and DN4 scores. Postoperative neurological deficits occurred in 14 patients (67%), with 11 having a sensory deficit and 7 a motor weakness. Eleven did not exist before surgery (6 sensory, 5 motor). In the postoperative deficit subgroup, 6 schwannomas involved the brachial plexus, 4 the ulnar nerve, and 4 the median nerve. All patients who had a fascicular resection because tumor enucleation was not feasible were in the postoperative deficit subgroup. Ten patients had either unchanged or worse QuickDASH and/or DN4 scores after surgery. Surgical treatment of schwannomas can lead to postoperative complications. Although none of our findings were statistically significant, advanced age, large tumor size, more than 16months between the first symptoms and surgery, and brachial plexus location seem to be more frequently observed in those with a postoperative neurological deficit.

Soft tissue tumours of the elbow: current concepts

Soft tissue tumours of the elbow are mostly benign. Malignant tumours in this area, although uncommon, often present unique clinical and histopathological characteristics that are helpful for diagnosis.Management of soft tissue tumours around the elbow may be challenging because of their rarity and the proximity to neurovascular structures. Careful staging, histological diagnosis and treatment are essential to optimize clinical outcome. A missed or delayed diagnosis or an improperly executed biopsy may have devastating consequences for the patient.This article reviews the most common benign and malignant soft tissue tumours of the elbow and discusses the clinicopathological findings, imaging features and current therapeutic concepts. Cite this article: EFORT Open Rev 2019;4:668-677. DOI: 10.1302/2058-5241.4.190002.

[Tumor involving the sciatic nerve: neurinoma or neurofibroma? Can MRI make the difference?]

The sciatic nerve is the terminal branch of the sacral plexus. Sciatalgia is a nerve root pain. In most cases, sciatica originates from degenerative disc disease. Tumor involving the sciatic nerve is extremely rare. We here report the case of a 33-year old patient with nerve tumor detected on MRI performed for drug-resistant sciatica. Tumor involving the sciatic nerve is rare and diagnosis is difficult. MRI data are crucial for establishing an effective surgical approach.

Interfascicular Resection of Benign Peripheral Nerve Sheath Tumors

Background

Interfascicular resection is a surgical technique used to safely treat benign peripheral nerve sheath tumors through careful dissection of functional neural elements off the tumor surface^1,2.

Description

Proper operative technique is essential to improving symptoms, preserving neurologic function, and minimizing the chance for recurrence. Accurate tumor localization, ideal patient positioning, and placement of a longitudinal incision permit adequate exposure. Prior to tumor resection, normal nerve should be identified proximally and distally and controlled with vessel loops. This allows functional fascicles streaming around the tumor in the pseudocapsule to be visualized during resection. A fascicle-free window is identified on the tumor surface through visual inspection and intraoperative neurophysiology monitoring if desired. The pseudocapsule layers are divided with a sharp instrument until a smooth and shiny true capsule layer is found. This plane should have minimal resistance and is developed circumferentially until the tumor can be enucleated in toto. At the poles of the tumor, a single nonfunctional nerve fascicle that courses into the tumor is typically found. If there is >1 fascicle running into the tumor, further pseudocapsule layers should be undermined to sweep fascicles off the true capsule surface. The entering-exiting fascicle can be tested for function and is cut sharply. The specimen should be sent to pathology for permanent sectioning. The sides of the pseudocapsule are spread in opposite directions to evaluate for residual tumor, and any remaining tumor is removed if it can be done safely. Meticulous hemostasis is achieved, and the surgical site is closed in anatomical layers.

Alternatives

Pain is the most common presenting symptom, and neuroleptic medications should be used in escalating dosage prior to surgical intervention. Nonoperative medical therapy does not typically result in symptom freedom, and patients often opt for resection. For tumors that are suspected of being malignant, an image-guided percutaneous or open biopsy and staging (positron emission tomography and/or computed tomography scans of the chest, abdomen, and pelvis) are recommended prior to treatment planning. For symptomatic benign extremity lesions, surgical resection is the treatment of choice, and adjuvant therapies like radiation and/or chemotherapy are not recommended. For malignant lesions, more aggressive surgery (wide resection or amputation) and preoperative, intraoperative, or postoperative radiation with or without chemotherapy are often utilized.

Rationale

The treatment approach depends on a variety of presenting features such as onset, progression, symptom severity, tumor size, location, imaging features, presence of a syndrome, and patient age. There is little benefit from the resection of an incidentally found, small, nongrowing lesion. The most common reasons for removal of extremity lesions are a painful mass and/or radiating "nerve" pain. There is a high likelihood of relieving the symptoms and minimizing the risk of recurrence, and a relatively low risk of causing neurologic injury. The procedure provides a definitive diagnosis. For patients with severe pain, progressive weakness, rapid tumor growth, or concerning imaging characteristics, biopsy should be considered to determine malignant potential.

Predictive factors for complications after surgical treatment for schwannomas of the extremities

Background

Schwannomas are well-encapsulated, benign neoplasms, and enucleation is a standard operation procedure. The incidence of neurological complications after surgical treatment for schwannomas of the extremities varies, and there is no consensus concerning predictive factors for complications. The aim of this study was to elucidate predictive factors for complications after surgical treatment of schwannomas that develop in the major nerves of the extremities.

Methods

A total of 139 patients with 141 schwannomas arising in major nerves were retrospectively analyzed. Data regarding preoperative clinical features, the postoperative neurological complications, and clinical course of complications, with a median follow-up period of 2 months (range, 0.5–96), were obtained. Predictive factors for complications were statistically analyzed.

Results

Postoperative complications occurred in 49 lesions (34.8%), including 42 with sensory disturbance and 8 with motor weakness. In univariate analysis, older age, tumors originating from the upper extremity, and major motor nerve involvement were associated with a higher complication rate (p = 0.03, p = 0.003, and p = 0.001, respectively). In multivariate analysis, major motor nerve involvement was an independent predictive factor for postoperative complications (p = 0.03). Almost all complications gradually improved, but 6 out of 8 patients with motor weakness did not show full recovery at the final follow-up.

Conclusions

Schwannomas originating from major motor nerves can lead to a higher risk for postoperative complications.

Go for the Gold: A “Plane” and Simple Technique for Resecting Benign Peripheral Nerve Sheath Tumors

BACKGROUND

Intraneural dissection is a useful technique for achieving gross total resection and preserving functional fascicles for peripheral nerve tumors. Finding the correct tissue plane is the critical step for safe successful enucleation. The authors hypothesized that the yellow color of benign nerve tumors can be used to identify surgical planes.

OBJECTIVE

To describe a technique to find the correct intraneural dissection plane based on a quantified yellow appearance during resection of benign peripheral nerve sheath tumors.

METHODS

Intraoperative photographs were reviewed to determine the percentage of yellow that tumors appeared at different phases of surgery. A technique was developed to quantitatively measure the amount of yellow using Photoshop. Previously published journal articles containing color images of peripheral nerve tumor resections were also analyzed for yellow tumor color.

RESULTS

There were 24 patients with suitable images to permit measurement of color for 3 steps of the procedure. The average percentages of yellow for tumor exposure, tumor resection, and removed specimen were 36.5%, 59.1%, and 80.4%, respectively (P < .001). Three publications were found that contained high-quality images of at least 2 phases of the surgery with average yellow content of 47.4% and 84% (P < .01).

CONCLUSION

The simple observation that a benign nerve sheath tumor is yellow in color can be used to guide surgical resection and achieve excellent outcomes. Intraneural dissection through the pseudocapsule should be pursued layer by layer until a yellow true capsule is found. By sparing functional nervous tissue within the pseudocapsule, this technique may lead to improved neurological outcomes.

Saphenous nerve schwannoma as a cause of vascular claudication - case report and review of the literature

Schwannomas are peripheral nerve tumours that are uncommon. They typical present with a palpable mass, pain or neurological changes. We describe a saphenous nerve schwannoma compressing the superficial femoral artery and causing vascular claudication. We also review the literature.

Analysis of Peripheral Nerve Schwannoma Pseudocapsule

BACKGROUND

Using proper surgical technique, schwannomas can be resected safely, with a low recurrence rate and high likelihood of improvement in symptomatology. There are multiple peritumoral tissue layers, and finding the correct plane is critical to safe tumor enucleation. The contents of the pseudocapsule tissue surrounding a schwannoma are not well described, and the consequences of resecting or leaving pseudocapsules are unknown.

METHODS

An institutional database was searched for any pathology reports that contained both of the words "schwannoma" and "capsule." Charts and histopathologic specimens were reviewed to determine the contents of various tissue layers and determine if there was any correlation between pseudocapsular contents and clinical outcomes.

RESULTS

A pseudocapsule was separately sent for pathology in 36 patients during schwannoma resection. Ten pseudocapsule specimens contained microscopic foci of tumor. In a separate 6 patients, there was evidence of nerve fascicles. There were no correlations between the tumor or nerve in the pseudocapsule and postoperative neurologic deficits. After an average follow-up time of 3.1 years, no patients developed a recurrence either clinically or on follow-up imaging (imaging available in 52.7%). Histopathologically, the pseudocapsule was made of dense hypocellular collagen and occasionally contained arteries, veins, and nerve fascicles.

CONCLUSIONS

The pseudocapsule surrounding a schwannoma occasionally contained nerve tissue and blood vessels. While a microscopic focus of tumor was often found in this tissue layer, recurrence is exceedingly rare and did not occur in this case series. The risk of undue pseudocapsule dissection likely outweighs any negligible benefit from microscopic cytoreduction.

Large retroperitoneal schwannoma: a rare cause of chronic back pain

Schwannomas are tumours that arise from Schwann cells of the peripheral nerve sheath and rarely occur in the retroperitoneum. We report a 45-year-old woman who presented with a 2-year history of continuous progressive right-sided lower back and dull flank pain radiating into her posterolateral thigh. Abdominal magnetic resonance imaging showed a homogenous soft-tissue tumour with thick capsular lining, which lay in the right retroperitoneum. The tumour was removed at surgery. A histological examination confirmed the diagnosis of benign encapsulated cellular schwannoma. Complete tumour excision should be regarded as the treatment of choice for benign retroperitoneal schwannomas. Successful treatment of these tumours requires thorough preoperative planning and a multidisciplinary approach.

Utility of intraoperative monitoring with motor-evoked potential during the surgical enucleation of peripheral nerve schwannoma

Although it is thought that the surgical enucleation of schwannomas can be easily performed, certain patients present with postoperative neurological symptoms. The present study examined the utility of intraoperative motor-evoked potential (MEP) in predicting neurological deficits following the surgical enucleation of peripheral nerve schwannoma. The current study included 23 patients and MEP was performed using transcranial electrical stimulation. In three cases, the MEP decreased to <50% of the preoperative value; however, in two cases that involved the peroneal nerve and tibial nerve, results appeared to be false positives induced by a tourniquet during surgery. In another case, the MEP was completely lost following enucleation of the tumor from the sciatic nerve, which recovered to 61% of the original MEP within 10 min. This patient presented with common peroneal palsy postoperatively. By contrast, another case involving the lumbar nerve root and in which there was reversible postoperative motor loss, the MEP did not change intraoperatively. Postoperative neurological deficit occurred in 22% of patients in the present study, which is similar to that of previous reports. The present study also demonstrated that even if a nerve is not transected or injured, traction or compression of a peripheral nerve may induce ischemia, which can be monitored using MEP. Although MEP alone was not able to predict postoperative transient sensory or motor deficits, the combination of MEP with other methods of neurological monitoring may improve accuracy and should be investigated in future studies.

Retrospective Analysis of 20 Patients With Schwannomas: Magnetic Resonance Imaging Characteristics, Pain, and Outcomes Following Excision

A Tinel's sign, a percussion-induced, painful sensation, has been reported as the most useful sign for diagnosing a schwannoma. On magnetic resonance imaging, schwannomas often exhibit a split fat sign and a target sign. The typical treatment for schwannomas is surgical excision; however, excision often results in high rates of neurological deficit. The authors retrospectively reviewed 20 patients who underwent excision of a schwannoma from 2007 to 2015. Twenty patients presented with a split fat sign and 12 patients presented with a Tinel's sign on magnetic resonance imaging. Only 3 patients presented with a target sign on magnetic resonance imaging. The operative approach involved removing the schwannoma, preserving the nearby nerve fascicles, and leaving the epineurium open. Follow-up ranged from 3 to 91 months (average, 29 months). At final follow-up, all patients were pain free. Nineteen patients had normal sensation and full function of their affected limb. One patient developed postoperative posterior interosseous nerve palsy. A Tinel's sign, preoperative pain, and a split fat sign on preoperative magnetic resonance imaging are the clinical symptoms most useful for diagnosing a schwannoma. Schwannomas can be safely removed via intracapsular surgical excision with minimal complications, yielding eradication of preoperative pain, normal sensation, and full function. [Orthopedics. 2017; 40(6):e1036-e1043.].

Risk factors for neurological complications after operative treatment for schwannomas

Schwannoma is a common benign soft tissue tumor. Although schwannomas can be theoretically enucleated without nerve damage, neurological complications occasionally develop following enucleation. The aim of this study was to elucidate the incidence of and risk factors for postoperative neurological complications following schwannoma enucleation. Ninety-eight schwannomas from 95 patients that were treated by surgical excision between January 2003 and December 2014 were included in this retrospective case series study. Patients were 49 men and 46 women with a median age of 60.5years (range, 22-87years). The incidence of postoperative neurological complications was evaluated in all the patients, and characteristics, such as age, tumor size, sex, preoperative symptoms, MRI findings, tumor location, and the nerve of origin, were compared between the cases with or without complications at the last follow-up. In our study population, postoperative neurological complications were observed in 18.4% of the cases. In univariate analysis, preoperative sensory disturbance, tumor location, and the nerve of origin were associated with the incidence of postoperative neurological complications (p<0.001, p=0.034, and p=0.003, respectively). In multivariate analysis, tumors showing preoperative sensory disturbance and tumors located in the proximal aspect of the limbs were identified as independent risk factors for postoperative neurological complications (p<0.001 and p=0.014, respectively). A certain percentage of schwannoma cases undergoing enucleation would show postoperative neurological complications. Therefore, patients with schwannoma, in particular, those with risk factors for postoperative neurological complications, should be informed regarding the possibility of postoperative complications. In cases of schwannoma enucleation, the procedure should be meticulously performed to minimize the damage to the affected nerve of origin.

Neurilemmomas of the Hand—A Review of the Clinical Presentation, Surgical Outcome, and Potential Risk Factors

Introduction

Neurilemmoma of the hand may not usually present with the classic triad (mass, differential mobility, Tinel's sign). Failure to recognize a neurilemmoma may result in the inadvertent injury of nerves. Preoperative diagnosis is very important and challenging.

Materials and Methods

A retrospective study of patients who underwent surgery for neurilemmoma of the hand between 2001 and 2013 was conducted. Their clinical presentation, surgical outcome and potential risk factors were reviewed.

Results

Twenty-eight cases of neurilemmoma arising from digits and hands in 28 patients were retrieved for study. Seventeen were male and 11 were female; the mean age at surgery was 57.1 years old and mean follow-up was 15.4 months. Nineteen lesions were on the volar side and the others were on the dorsal side. Volar digital nerve was the most common site of involvement. All patients presented with a mass, with an average duration of symptoms of 41.1 months; 35.7% had local tenderness. Differential mobility and Tinel's sign could be elicited in 39.3% and 21.4%, respectively. Correct preoperative diagnosis was made only in 25% of cases. At final follow-up, 82.1% of patients was symptom-free. Numbness, local tenderness and hypertrophic scar were reported in 7.1%, 7.1% and 3.6% of patients, respectively. No recurrence and no wound complications were noted. No reoperation was necessary. Multiple lesions and a positive Tinel's sign were associated with less satisfactory outcome and increased risk of postoperative complications as shown by the statistical analysis.

Conclusion

Neurilemmoma should be one of the differential diagnoses when dealing with hand masses. Tinel's sign should be done routinely on examination to facilitate correct preoperative diagnosis. Loupe magnification should be used during operation for optimal surgical outcome.

High-Resolution Ultrasound of Schwannomas of the Limbs: Analysis of 72 Cases

Schwannomas are common benign tumors that develop in peripheral nerves. High-resolution ultrasound (HRUS) is an effective imaging modality in clinics. The aim of this study was to define the value of HRUS in diagnosing schwannomas that originate from different nerves in limbs. We reviewed the ultrasound and surgical records of 72 pathologically confirmed schwannomas in the limbs of 60 patients. Results revealed that 44 (61.1%) of 72 cases, 44 (75.9%) of 58 cases and 0 (0%) of 14 cases received an overall correct pre-operative diagnosis, a correct pre-operative diagnosis in nerve trunks and a correct pre-operative diagnosis in small branches, respectively. Identification of the nerve of origin of schwannomas through HRUS likely increased confidence in diagnosing these benign tumors.

Nerve sheath tumor, benign neurogenic slow-growing solitary neurilemmoma of the left ulnar nerve: A case and review of literature

This paper represent a report of a case with ulnar nerve schwannoma (neurilemmoma), benign neurogenic slow-growing, tumors originating from Schwann cells along the course of a nerve (1) (2) (3). Schwannomas are the most common tumors of the peripheral nerves which occur in the adults (0.8–2%) (5). Usually they progress slowly and so they can remain painless swellings for a few years before other symptoms appear. Most of these lesions could be diagnosed clinically, are mobile in the longitudinal plane along the course of the involved nerve but not in the transverse plane (7). EMG, MRI, and ultrasonography are useful tools in the diagnosis. The definitive treatment of benign peripheral nerve schwannomatosis is complete enucleation of the tumor mass without damaging the intact nerve fascicles followed by confirmatory hystopathological examination (12). We present the case of a 62 years old right hand-dominant female who notice a slow increasing bulge over the inner aspect of her distal volar left forearm superior to the wrist, for a longer period of time not exactly specified; this was tracked and associated by pain, tingling and numbness over inner one and half fingers of her left hand in progress until the presentations. A diagnosis of soft-tissue tumor was presumed clinically. The other investigations were ultrasonography (US), nerve conduction studies (NCSs) such as sensory nerve action potential (SNAP) and compound muscle action potential (CMAP). In this case IRM was suggestive of a benign growth in her left ulnar nerve in the forearm region. Microsurgical techniques were used for ample enucleation of the tumor the distal volar left forearm. Subsequent histopathological examination confirmed the presumed diagnosis of a benign cellular schwannoma. At her last follow-up one month after surgery, the patient was neurological gradually improving sensory and motor function and she is highly satisfied with the results of surgery.

Symptomatic small schwannoma is a risk factor for surgical complications and correlates with difficulty of enucleation

Postoperative neurological deficits of schwannomas are the complications that we want to avoid most. Predicting postoperative neurological deficits is crucial; however, the correlation between preoperative symptoms and neurological findings with postoperative neurological complications has not yet been completely clarified. Here we analyzed the risk factors for postoperative neurological complications. The study included 131 tumors from 107 patients histologically confirmed as schwannomas, which developed in the extremities and trunk without spinal cord involvement. The correlation between clinical findings and postoperative complications were statistically analyzed. One-hundred three tumors (78.6 %) had the preoperative neurological symptoms; these symptoms were detected in 93.3 % of small tumors (<4 cm(3)). We defined it as follows about the anatomical location of schwannomas. One is "central type" that normal nerve bundles widely splayed over the tumor's capsule (tumor located in the central region of the nerve). Another is "peripheral type" that easy to enucleate without neurolysis (tumor located in the peripheral region of the nerve). Static analysis showed a significant difference in the Tinel sign, numbness, and postoperative neurological deficits (p = 0.04, 0.006, p < 0.001, respectively). Twenty-one cases (16.0 %) showed new postoperative neurological symptoms, including numbness in 12 cases, dysesthesia in three cases, pain in three cases, and slight motor palsy in two cases. In statistical analysis, small tumors (<4 cm(3)) significantly correlated with Tinel sign (p < 0.001), and was marginally significant with postoperative neurological deficits (p = 0.05). Moreover, small tumors (<4 cm(3)) accompanying numbness preoperatively significantly correlated with postoperative neurological deficits (p = 0.04). Small (<4 cm(3)) tumors significantly correlated with the preoperative neurological symptoms. Those tumors accompanying numbness also significantly correlated with the difficulty of the enucleation and postoperative neurological deficits. These findings will help to predict the neurological complication.

Results of surgical treatment of schwannomas arising from extremities

Schwannomas are benign neoplasms derived from Schwann cells. In this work, we present our experience in operative management of schwannomas and analyse results of treatment. Clinical material consisted of 34 patients, in whom 44 schwannomas located in extremities were excised between 1985 and 2013. Thirty-five tumours originated from major peripheral nerves and 9 from small nerve branches. Postoperatively, in the first group of tumours, pain resolved in 100%, paresthesias in 83.3%, and Hoffmann-Tinel sign in 91.6% of the patients. Improvement in motor function was noted in 28.5% of the cases, in sensory function: complete in 70%, and partial in 15%. The most frequently affected major peripheral nerves were the ulnar (11 tumours) and median (5 tumours) nerves. Schwannomas originating from small nerve branches were removed without identification of the site of origin. After their resection, definitive healing was achieved. Conclusions. (1) Schwannomas located in extremities arise predominantly from major peripheral nerves, most commonly the ulnar and median nerves. (2) Gradual tumour growth causes exacerbation of compression neuropathy, creating an indication for surgery. (3) In most cases, improvement in peripheral nerve function after excision of schwannoma is achieved. (4) The risk of new permanent postoperative neurological deficits is low.

Results of surgical treatment of schwannomas arising from extremities

Schwannomas are benign neoplasms derived from Schwann cells. In this work, we present our experience in operative management of schwannomas and analyse results of treatment. Clinical material consisted of 34 patients, in whom 44 schwannomas located in extremities were excised between 1985 and 2013. Thirty-five tumours originated from major peripheral nerves and 9 from small nerve branches. Postoperatively, in the first group of tumours, pain resolved in 100%, paresthesias in 83.3%, and Hoffmann-Tinel sign in 91.6% of the patients. Improvement in motor function was noted in 28.5% of the cases, in sensory function: complete in 70%, and partial in 15%. The most frequently affected major peripheral nerves were the ulnar (11 tumours) and median (5 tumours) nerves. Schwannomas originating from small nerve branches were removed without identification of the site of origin. After their resection, definitive healing was achieved. Conclusions. (1) Schwannomas located in extremities arise predominantly from major peripheral nerves, most commonly the ulnar and median nerves. (2) Gradual tumour growth causes exacerbation of compression neuropathy, creating an indication for surgery. (3) In most cases, improvement in peripheral nerve function after excision of schwannoma is achieved. (4) The risk of new permanent postoperative neurological deficits is low.

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.

Sarcoma excision and pattern of complicating sensory neuropathy

A potential complication of sarcoma excision surgery is a sensory neurological dysfunction around the surgical scar. This study utilised both objective and subjective sensation assessment modalities, to evaluate 22 patients after sarcoma surgery, for a sensory deficit. 93% had an objective sensory deficit. Light touch is less likely to be damaged than pinprick sensation, and two-point discrimination is significantly reduced around the scar. Results also show that an increased scar size leads to an increased light touch and pinprick deficit and that two-point discriminatory ability around the scar improves as time after surgery elapses. 91% had a subjective deficit, most likely tingling or pain, and numbness was most probable with lower limb sarcomas. Results also demonstrated that there were no significant relationships between any specific subjective and objective deficits. In conclusion, sensory disturbance after sarcoma surgery is common and debilitating. Efforts to minimize scar length are paramount in the prevention of sensory deficit. Sensation may also recover to an extent; thus, sensory reeducation techniques must become an integral aspect of management plans. Finally to obtain a comprehensive assessment of sensory function, both objective and subjective assessment techniques must be utilised.

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.

Neurilemmoma of median nerve

Neurilemmomas constitute one of the most common tumors of peripheral nerves. Rarer amongst them is their occurrence in median nerve in the region of arm. A sixteen-year-old female presented with painless mass in right arm which was non-tender on palpation with positive Tinel's sign and no motor or sensory deficit in the affected arm. Ultrasound examination revealed an eccentrically arising mass of size 19 × 11 mm along median nerve. MRI study revealed a mass homogenously isointense on T1 weighted images and hyperintense in T2 weighted images placed eccentrically in relation to median nerve in arm. Excisional biopsy under loupe magnification was carried out which revealed the mass to be neurilemmoma. This slowly growing benign tumor of peripheral nerves with an incidence of 5% with 14% involvement of Median nerve can be enucleated from the nerve with little or no damage. In spite of advanced imaging studies the mass cannot be differentiated preoperatively from another peripheral nerve sheath tumor neurofibroma. Both these tumors although bearing some clinical and imaging resemblance carry different intraoperative findings, histopathological features and post-operative results.

Therapeutic effect and risk factors for complications of excision in 76 patients with schwannoma

BACKGROUND

Benign schwannoma is the most common tumor of peripheral nerves. However, the clinical course of excision and risk factors associated with postoperative neurological deficits are not well known. We evaluated the incidence of preoperative symptoms, the incidence of postoperative neurological deficits, and the risk factors of neurological deficits.

METHODS

We retrospectively reviewed data of 76 patients with schwannomas treated at our institution. We reviewed the clinical characteristics, and postoperative results, and determined the possible risk factors influencing the development of complications.

RESULTS

Excision of schwannoma improved the Tinel-like signs in 47 of 51 patients and spontaneous pain in 14 of 15. Eleven of 17 patients with sensory deficits showed complete recovery, but six continued to show deficits with or without improvement. Motor deficits that were observed in four patients persisted in one. New neurological deficits developed in 21 patients and persisted until final follow-up in 8. Tinel-like signs was the risk factor of surgery-related neurological deficits (p = 0.009).

CONCLUSIONS

New deficits developed predominantly in patients with preoperative Tinel-like signs. Attention should be given to patients with the factor.

Clinical evaluation and management of benign soft tissue tumors of the extremities

Benign lesions comprise a majority of soft tissue tumors. It has been estimated that their incidence outnumbers that of malignant tumors by a factor of at least 100 [1]. While history and physical examination can start the diagnostic process, imaging including the use of magnetic resonance imaging can be more helpful. Biopsy of these tumors is sometimes necessary and can be performed in a number of ways, often in conjunction with definitive treatment. Specific diagnostic and treatment strategies for a number of the more commonly encountered benign soft tissue tumors including lipomas, pigmented villonodular synovitis and hemangiomas are reviewed. An algorithm for the management of benign soft tissue tumors is discussed.

Schwannoma in the upper limbs

Schwannomas are the commonest tumours of peripheral nerves. Despite the classical description that schwannomas are well encapsulated and can be completely enucleated during excision, a portion of them have fascicular involvement and could not be completely shelled out. A retrospective review for 8 patients was carried out over 10 years. 75% of schwannoma occurred over the distal region of upper limb (at elbow or distal to it). It occurs more in the mixed nerve instead of pure sensory or motor nerve. 50% of patients had mixed nerve involvement. Fascicular involvement was very common in schwannoma (75% of patients). Removal of the tumour with fascicles can cause functional deficit. At present, there is no method (including preoperative MRI) which can predict the occurrence of fascicular involvement; the authors therefore proposed a new system to stratify patients who may benefit from interfascicular nerve grafts. In this group of patients, the authors strongly recommend that the possibility and option of nerve graft should be discussed with patients prior to schwannoma excision, so that nerve grafting could be directly proceeded with patient consent in case there is fascicular involvement of tumour found intraoperatively.

Surgical treatment of typical peripheral schwannomas: the risk of new postoperative deficits

BACKGROUND

Although peripheral schwannomas can be resected without postoperative neurological complications, surgeons must anticipate the possibility that new neurological deficits could develop. In order to evaluate the risk of neurological complications in the surgical treatment of these tumours, we performed a retrospective review of cases involving schwannomas in the extremities, as well as an analysis of the related literature.

METHOD

We reviewed a combined series of 72 schwannomas from the extremities presenting for surgical excision. Meticulous analysis of the files was undertaken, searching for pre-operative findings that could be more frequent in patients with surgical complications. The incidence, severity, and transitory nature of post-operative complications in our series was observed and compared against the literature.

RESULTS

Eleven patients (15.2 %) developed new neurological deficits after surgery: sensory disturbance in seven cases, motor weakness in three, and a single wound hematoma. Most of these complications were temporary. Statistical analysis demonstrated a positive relationship between the presence of complications and both patient age under 50 years (p = 0.02) and tumours greater than 3 cm in greatest diameter (p = 0.02).

CONCLUSIONS

Although relatively infrequent, the potential for novel post-operative deficits after the surgical treatment of peripheral schwannomas does exist and should be included during pre-operative counseling.

Non-vestibular head and neck schwannomas: a 10-year experience

Schwannomas are rare and slow growing tumours, arising from Schwann cells which provide myelin; less than 1% of them degenerate into a malignant state. Although most studies are based on acoustic schwannomas, the majority of these tumours are non-vestibular and extracranial. Up to 45% of them can be localised in head and neck districts, where they represent a diagnostic challenge because they are in differential diagnosis with lipoma, brachial cyst, paraganglioma and adenopathy. Between February 2002 and September 2012 our experience considers 18 patients affected by schwannomas localised in the neck in 14 cases, in the oral cavity in 2 cases, in the upper lip in 1 case and finally in the nose in 1 case. A painless neck mass was the major symptom referred, as well as dysphonia and oral pain. Ultrasound scan with fine needle aspiration biopsy was done in half of the group and was diagnostic in 30%, whereas magnetic resonance imaging was diagnostic in 77%, confirming its primary role in diagnostic work-up. The surgical approach was mainly by cervical incision and the intraneural extracapsular enucleation was the technique used without nerve injury in 89% of cases. Follow-up period was 6-120 months and no evidence of relapse was registered.

Intramuscular schwannoma of the musculocutaneous nerve: An uncommon clinical presentation

A schwannoma is a benign peripheral nerve sheath tumor composed exclusively of Schwann cells. A major-nerve schwannoma with an intramuscular location is an extremely rare condition. We present a rare case of intramuscular schwannoma originating from the musculocutaneous nerve in a 71-year-old female. The patient presented with a 7-month history of a slowly growing, painless mass in the medial aspect of the proximal upper arm. Magnetic resonance imaging revealed an oval-shaped intramuscular soft tissue mass with iso-signal intensity relative to skeletal muscle on T1-weighted images and high signal intensity on T2-weighted images. A rim of fat surrounding the mass, suggesting the split-fat sign, was also observed. The tumor was completely enucleated using an intracapsular technique. Histological examination confirmed the diagnosis of schwannoma consisting of Antoni A and B areas. There was no immediate neurological deficit following surgery. The patient had no evidence of local recurrence and no neurological deficit at final follow-up. To the best of our knowledge, this is the first report of musculocutaneous nerve schwannoma within the coracobrachialis muscle.

Surgical outcome of schwannomas arising from major peripheral nerves in the lower limb

PURPOSE

The treatment of symptomatic Schwannoma is surgical excision. However, in the case of major peripheral nerves with motor function, there are concerns including neurological complications following surgery. This study was designed to evaluate the surgical outcome of Schwannomas originating from major peripheral nerves of the lower limb. Additionally, we sought to find out the predictable factors for permanent neurological deficits.

METHODS

Between 2004 and 2008, 30 consecutive Schwannomas underwent simple excision or enucleation. Surgical outcomes after excision were evaluated with an emphasis on neurological deficits and recurrence. Neurological complications were classified as major or minor neurological deficits and evaluated immediately after surgery and at final follow-up. Risk factors for development of neurological deficits were identified.

RESULTS

Twenty-three patients (23/30, 76.7 %) developed neurological deficits immediately after surgery. After a mean of 58.8 months (32-79 months), 19 patients (19/30, 63.3 %) showed no residual neurological deficits. Among the remaining 11 (11/30, 36.7 %), nine patients had tolerable symptoms and two patients had major neurological deficits including significant motor weakness and sensory impairments. Larger tumours tended to be at greater risk of neurological deficit after surgery. One recurrence of the tumour was seen two years after surgery. There were no cases of reoperation or malignant transformation

CONCLUSIONS

In the majority of cases, Schwannomas in the lower limb can be excised with acceptable risk for neurological deficits. However, meticulous dissection is required in large-sized Schwannomas because these tumours seem to have a higher frequency of fascicular injury during dissection.

Advantages of intra-capsular micro-enucleation of schwannoma arising from extremities

BACKGROUND

Schwannoma is the most common tumor of the peripheral nerves, with surgical enucleation being the established treatment modality. However, some schwannomas cannot be easily enucleated and this sometimes results in iatrogenic nerve injury even with atraumatic procedures. Here we present a retrospective review of the management of schwannoma in the extremities and compare clinical outcomes from the two techniques of extra-capsular and intra-capsular enucleation.

METHODS

We reviewed 36 schwannomas from 35 patients who underwent surgical excision of schwannomas arising from the extremities. Twenty had undergone extra-capsular resection and 16 had undergone enucleation using the intra-capsular technique. The post-operative neurological deficits were graded as minor, major, and transient. The duration of symptoms, maximum tumor diameter and site of occurrence were compared between patients with the three grades of deficit.

RESULTS

In total, 22 patients developed no sensory changes following enucleation of schwannoma or only temporary and minor changes that had fully resolved within 6 months. Ten patients developed new neurological deficits following surgery that took longer than 6 months to resolve. Four patients experienced new motor deficits or paresthesia following operation that had still not recovered at the final follow-up, all of whom underwent enucleation using the extra-capsular technique. Neurological deficit after enucleation was significantly lower using the intra-capsular compared with the extra-capsular technique. Patient age, duration of symptoms, maximum diameter of the tumor and site of occurrence did not influence the neurological deficit following enucleation of schwannoma.

CONCLUSION

These results support intra-capsular micro-enucleation as a safe and reliable treatment for every type of schwannoma. To minimize the risk of nerve injury, en bloc resection should not be used because the main purpose of schwannoma surgery is the relief of symptoms, not tumor resection. Thorough pre-operative counseling of patients to inform them of the potential occurrence of neurological deficit is important.