Peripheral nerve schwannomas--an analysis of 16 patients

Long-term Follow-up with MRI Scans After Enucleation of Peripheral Nerve Schwannomas: Results from a Single-center Case Series

BACKGROUND

Enucleation is a surgical technique to resect peripheral nerve schwannomas. The procedure has a low risk for postoperative deficit, but a small chance for recurrence, because tumor cells may remain inside the pseudocapsule that is left after resection. Magnetic resonance imaging (MRI) scans are frequently performed after surgery to investigate potential residual tumor, but currently there is little information in the literature on the value of follow-up with MRI.

MATERIAL AND METHODS

All patients who underwent enucleation of a peripheral nerve schwannoma between October 2013 and June 2022 were included. Postoperative MRI scans (gadolinium-enhanced) made at different time points after the surgery were re-examined for residual enhancement. Patients with residual enhancement were contacted to inform whether symptoms had recurred.

RESULTS

A total of 75 schwannoma enucleations in 74 patients were included. The first postoperative MRI scan, performed 3 months after the surgery, showed no residual enhancement in 50 patients. In the remaining 24 patients, another MRI scan was made 1 year after the surgery, which still showed a possible remnant in 11 patients. On the third MRI scan, performed 2 years after enucleation, there were 7 suspected cases (9%). None of these patients had clinical symptoms at a mean postoperative follow-up of 5 years.

CONCLUSIONS

Our data show that the value of postoperative MRI scans after enucleation of peripheral nerve schwannomas is limited, because residual enhancement in the beginning can be non-specific and the small percentage of patients, that persistently had a potential remnant, were all asymptomatic.

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.

Ultrasound-guided brachial plexus nerve block in a patient with a left palmar schwannoma: A case report

RATIONALE

Ultrasound-guided brachial plexus block is a common anesthetic procedure used in upper extremity surgery. However, it may not be a suitable option for some patients.

PATIENT CONCERNS

A 17-year-old woman with the left palmar schwannoma scheduled for surgical treatment received ultrasound-guided brachial plexus block. The anesthesia modalities of the disease were discussed.

DIAGNOSES

Based on the patient's complaints and clinical appearance, provisional diagnosis of neurofibroma was considered.

INTERVENTIONS

In this case, we present a case of ultrasound-guided axillary brachial plexus block used for upper extremity surgery in this patient. It was not easily and painlessly reduced in the surgery, although the visual analogue scale score was 0 and no motor movements of the left arm and palm were observed. The pain was relieved by intravenous injection of 50 mcg remifentanil.

OUTCOMES

Immunohistochemically labeled pathological examination confirmed the mass to be a schwannoma. There was no need to apply additional analgesia after surgery, although the patient felt numbness in the left thumb for 3 days follow up.

LESSONS

Even if there is painless when skin-cutting after implementation of brachial plexus block, the patient is painful when pulls the nerve around the tumor during excision. It is necessary to give an analgesic drug or anesthetize a single terminal nerve as a supplement for brachial plexus block in patients with schwannoma.

Recurrent schwannoma of digital nerve on both hands: A very rare case report

INTRODUCTION AND IMPORTANCE

Schwannoma is the most common benign tumor of peripheral nerves and usually occurs solitary with a very low risk of recurrence. Schwannoma of the hand, particularly involving the digital nerve, is sporadic and most commonly leads to a misdiagnosis due to its rarity. Histopathology remains the gold standard diagnostic, however, with a thorough physical examination and radiologic imaging, this benign tumor can be managed well with the preservation of nerve function.

CASE PRESENTATION

We reported a rare case of digital nerve schwannomas on the bilateral hands of a 52-year-old white male with one recurrent mass on the right hand despite a previously complete debulking of the mass.

CLINICAL DISCUSSION

Intraoperatively, we removed lobulated whitish-yellow masses and left the nerve origin of the tumor intact (common palmar digital nerve and ulnar-side digital nerve). The histopathology supported the diagnosis of schwannoma. At the one-year follow-up, there is no recurrence and the patient remains asymptomatic.

CONCLUSION

Determining differential diagnosis by both clinical and preoperative imaging is essential, especially in the case of recurrence and multiple tumorous lesions. Malignancy or malignant degeneration should still be kept in mind. Complete removal is needed to prevent recurrence followed by a long-term follow-up.

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.

Multinodular plexiform tumors of major peripheral nerves: A practical overview

BACKGROUND AND AIMS

Multinodular/plexiform schwannomas and neurofibromas of major nerves are rare: before surgery, differential diagnosis among these two uncommon variants is challenging. For both forms, surgical removal is recommended in case of progressive growth and worsening of neurological symptoms. Surgery has a higher risk of neurological damage than conventional schwannomas or neurofibromas. In literature, a comparison among these rare tumors is usually limited to the pathological aspect while specific surgical and clinical management indications are lacking. Cutaneous tumors of both forms arising from terminal peripheral nerves' branches might be treated by plastic surgeons while tumors of major nerves remain under neurosurgical competence. Here we report our recent neurosurgical experience on the matter, to furnish useful suggestions for the management of these tumors.

METHOD

We analyzed the clinical, radiological, and pathological data in a consecutive case series of plexiform/multinodular nerve tumors operated at our institution in the last five years.

RESULTS

In our series, neurofibroma type of plexiform tumors was more frequent than schwannoma type: two sporadic plexiform-multinodular schwannomas (patients 1, and 5) and three multinodular/plexiform Neurofibromatosis familial (Neurofibromatosis 1 / NF-1) (patients 2, 3, and 4). Surgery was complex when major nerves were involved. The early outcome appeared mostly related to the pre-surgical neurological conditions and histological grading.

INTERPRETATION

Although sharing some features, multinodular-plexiform schwannomas and neurofibromas have consistent differences from the clinical, surgical and pathological points of view.

A rare cause of sciatica: Sciatic nerve schwannoma - Report of one case with long subclinical course and misleading presentation

The authors report one case of schwannoma located in the sciatic nerve, just above the popliteal fossa. A sciatic localization is rare, observed in 1% of the patients. The misleading clinical presentation of this localization causes a delay in diagnosis. Magnetic Resonance Imaging (MRI) is the imaging modality of choice, but the final diagnosis is made by the histological examination of the tumor. Schwannoma should be surgically removed without division of the nerve trunk.

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.

Schwannoma of the long thoracic nerve in the left axilla: a case report

Schwannoma, which is also known as neurilemmoma, is a type of tumor that arises from the peripheral nerve sheaths. Cases of schwannomas located in different regions have been reported. Some schwannomas present as asymptomatic masses, while others cause discomfort, such as pain and numbness. Magnetic resonance imaging (MRI) is a valuable diagnostic tool. A 23-year-old woman presented to our hospital with a mass in the left axilla that was misdiagnosed as mammae erraticae. The patient also considered the condition to be mammae erraticae for approximately 14 months because of a lack of symptoms. MRI was recommended by a surgeon from the galactophore department. A giant schwannoma was found. The mass was surgically excised, while preserving the continuity of the long thoracic nerve. Routine histopathological analysis confirmed the presence of a benign schwannoma. Schwannomas located in the axilla are rare and may be easily misdiagnosed as mammae erraticae or enlarged lymph nodes. Early investigation is necessary to make the diagnosis, and surgical excision is usually curative.

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.

Diagnostic Imaging and Management of Common Intra-articular and Peri-articular Soft Tissue Tumors and Tumorlike Conditions of the Knee

Intra-articular (IA) and peri-articular (PA) tumors of the knee are frequently encountered by orthopaedic surgeons. Nonetheless, due to the possibility of great morbidity and potential mortality, it is important to recognize and differentiate between benign and malignant lesions in a timely manner. Therefore, the purpose of this article is to provide a concise, practical, and updated review of commonly encountered IA and PA tumors including intratendinous gout, synovial chondromatosis, schwannoma, pigmented villonodular synovitis, and synovial sarcoma, and a detailed description of differentiating features to include various imaging modalities.

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.

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.].

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.

Radioguided Occult Lesion Localization in Deep Schwannomas of the Peripheral Nerves: Results of a Preliminary Case Series

BACKGROUND

The detection of small deep schwannomas of the peripheral nerves has been increasing since the the use of precise neuroimaging techniques has become more widespread; however, although nonpalpable lesions can be well defined by images, it is often difficult to identify them during the surgical procedure. The authors report seven cases of nonpalpable small deep schwannomas surgically treated after their identification using the radioguided occult lesion localization (ROLL) technique.

METHODS

Seven men, whose ages ranged from 34 to 70 years (mean 52 years), presented with symptomatic nonpalpable peripheral nerve lesions; two cases involved the sciatic nerve, two the femoral nerve, two the radial nerve, and one the tibial nerve. Before the operation, all the patients were studied by ultrasonography and magnetic resonance imaging (MRI); 1 h before the surgery 3-5 MBq of ^99mTc labeled with human albumin macroaggregates was injected into the lesion. A gamma detection probe permitted the preoperative and intraoperative detection of the nonpalpable schwannomas.

CONCLUSIONS

The ROLL technique provides good support for identifying small lesions of the peripheral nerves both preoperatively and intraoperatively. This technique permits the use of minimally invasive approaches performed with local anesthesia, with good cosmetic results and acceptance by the patients.

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.

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.

Sciatic nerve schwannoma: a case report

We report on a 46-year-old woman with a sciatic nerve schwannoma. Magnetic resonance imaging revealed a well-defined, lobulated, intensely enhancing mass posterior to the left hip joint along the left sciatic nerve suggestive of neurogenic tumour. The Tinnel sign was positive on the posterior aspect of the left thigh. The tumour was excised without neural damage. Postoperatively, the patient showed no signs of any neurological deficit, and recovery was uneventful.

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.

Peripheral nerve tractography in soft tissue tumors: a preliminary 3-tesla diffusion tensor magnetic resonance imaging study

INTRODUCTION

This diffusion tensor magnetic resonance imaging (DTI) study aimed to clarify the relationship of peripheral nerves and soft tissue tumors (STTs) in 3D to optimize subsequent treatment.

METHODS

Twenty-six consecutive STT patients (histologically malignant, n=10; intermediate, n=3; and benign, n=13) underwent 3-Tesla MRI using an echoplanar DTI sequence. Deterministic tractography was performed. Fractional anisotropy (FA) values were measured within peritumoral and distant regions of interest.

RESULTS

Tractography depicted the 3D course of the sciatic (n=12), femoral (n=2), tibial (n=7), fibular (n=2), median (n=1), musculocutaneous (n=1), and ulnar (n=1) nerves in a regular (n=8 of 18, 44.4%) or thinned (n=7 of 18, 38.9%) fashion. The lowest peritumoral FA values, abrupt thinning, and/or complete discontinuity of trajectories were found in 2 cases with histologically proven tumoral nerve infiltration.

CONCLUSIONS

DTI clarifies the 3D topography between major peripheral nerves and STTs and may be helpful in the assessment of peripheral nerve infiltration by malignant tumors.

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.

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.

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.

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.

Multinodular/plexiform (multifascicular) schwannomas of major peripheral nerves: an underrecognized part of the spectrum of schwannomas

OBJECT

In clinical practice, schwannomas are among the most common types of nerve sheath tumors. Their clinical presentation, imaging characteristics, and operative features are well known. Over the past 20 years, clinical outcomes have improved due to resection of these tumors at a fascicular level. Despite these advances, a subgroup of patients with schwannomas is associated with a disappointing neurological outcome following resection. The purpose of this study was to correlate the imaging and histological features in this group of patients with more anatomically complex forms of schwannomas.

METHODS

In a retrospective review performed at their institution over a 10-year period, the authors found a subgroup of patients with complex multinodular/plexiform schwannomas affecting major peripheral nerves. Eleven patients were identified, and the clinical, imaging, and pathological features of their disease were reviewed.

RESULTS

The clinical presentation of multinodular/plexiform schwannomas of major peripheral nerves may be similar to that of conventional schwannomas, but their imaging features, operative appearance, and outcomes differ.

CONCLUSIONS

Preoperatively and intraoperatively, the distinguishing features of multinodular/plexiform schwannomas of major peripheral nerves may be subtle and can easily go unrecognized, thus explaining the often suboptimal surgical results. Familiarity with the imaging and operative features of multinodular/plexiform schwannomas will no doubt alter treatment approaches and improve neurological function in this subgroup of patients.

Rare asymptomatic presentations of schwannomas in early adolescence: three cases with review of literature

INTRODUCTION

Schwannoma also known as Neurilemoma is a benign neoplasm of the Schwann Cells of the neural sheath. They are usually found to occur in the extremities, but can also be found in the trunk, head and neck, pelvis, and rectum. It is seldom painful and usually remains small. It has no potential for malignancy unless the patient has multi-neural tumours. It usually presents as a slowly enlarging painless nodule somewhat movable beneath the surface, rarely becomes larger than 2cm in diameter and is most frequently diagnosed in 25-55 yrs of age.

PATIENTS AND METHODS

We report three rare, asymptomatic presentations of schwannomas at adolescent age, in the back, pancreas and in the cervical region with a review of the available literature.

CONCLUSION

Despite the rarity of the presentations, as encountered by us, similar swellings in the adolescent age group can be schwannomas and can be adequately managed surgically alone. This is what should be borne in mind, for 'what the mind knows is what the eyes see'.

Neurological deficit after surgical enucleation of schwannomas of the upper limb

We evaluated 56 patients for neurological deficit after enucleation of a histopathologically confirmed schwannoma of the upper limb. Immediately after the operation, 41 patients (73.2%) had developed a new neurological deficit: ten of these had a major deficit such as severe motor or sensory loss, or intolerable neuropathic pain. The mean tumour size had been significantly larger in patients with a major neurological deficit than in those with a minor or no deficit. After a mean 25.4 months (12 to 85), 39 patients (70%) had no residual neurological deficit, and the other 17 (30%) had only hypoaesthesia, paraesthesiae or mild motor weakness. This study suggests that a schwannoma in the upper limb can be removed with an acceptable risk of injury to the nerve, although a transient neurological deficit occurs regularly after the operation. Biopsy is not advised. Patients should be informed pre-operatively about the possibility of damage to the nerve: meticulous dissection is required to minimise this.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

CONCLUSIONS

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

Magnetic resonance imaging of peripheral nerve tumours in the upper extremity

Clinical assessment and various diagnostic tools, particularly magnetic resonance imaging (MRI), of tumours of peripheral nerves are used to get an accurate diagnosis and to plan surgical intervention. Our purpose was to examine the usefulness of MRI in assessing nerve tumours in the upper extremity. Medical records of 19 patients (20 MRI examinations) with 29 histopathologically verified benign nerve tumours were examined retrospectively. In 12/20 cases MRI suggested a correct diagnosis of the type of nerve tumour. An additional 3/20 cases had an uncertain diagnosis, but nerve relations to the tumour were established. In 5/20 cases MRI gave a doubtful diagnosis with no suspicion of the tumour being located in a nerve trunk. MRI can localise and diagnose a nerve tumour in the upper extremity in 75% of cases, but it is difficult to specify the type of tumour.

Tumours of peripheral nerves in the upper extremity: a 22-year epidemiological study

Peripheral nerve tumours are uncommon. Our aims were to calculate the incidence and relative frequencies, to define sites of nerve tumours and to judge preoperative symptoms and outcomes of intervention. The results of 53 patients, with 68 tumours and histopathological diagnoses of true neoplasms, who had been operated on at the Department of Hand Surgery, Malmo, Sweden, between 1986 and 2007, were analysed. Schwannomas were the most common tumour (n=42). The incidence of schwannomas was 0.62/100 000 inhabitants/year in Malmo during that time period. The median nerve was most affected, closely followed by the ulnar and digital nerves. The preferred sites were the forearm, the thumb, and the digits. The most common preoperative symptom was pain. Loss of sensation was the most common postoperative complication. However, 33/53 patients (62%) were completely free of symptoms after excision. Patients should be provided with meticulous information preoperatively.

[Schwannomas of the peripheral nerve in the hand and the upper limb: Analysis of 14 cases]

The Schwannomas are usually considered as enucleable lesions of which the excision under microscope doesn't entail a post-operative deficit. Having frequently observed the inclusion of fascicle in the tumor, we wanted to verify the absence of deficit in a retrospective survey. Our survey is composed of 14 patients operated of schwannoma of the superior member and whose mean age is 53 years old. All patients presented an average of nine months old palpable mass; the pain was present in four cases; paresthesiae in seven cases; irritatif syndrome in ten cases. A preoperative sensory deficit was present in two patients but without any case of preoperative motor deficit. The schwannoma was localized in eight cases in the hand, one case in the forearm, two cases in the elbow, two cases in the arm and one case in the armpit. The affected nerves were the digital ones in six cases, the main trunk of the median nerve in four cases, the trunk of the ulnaire nerve in three cases and the sensory branch of the radial nerve in one case. All tumors have been operated under a microscope. The enucleation was possible without fascicle lesion in six cases. In the eight other cases we have proceeded to a resection of indissociable fascicles. The diagnosis is confirmed by the histologycal examination in all cases. In postoperative, the two patients that presented a preoperative sensory deficit no longer presented it. On the contrary, three patients that didn't have any preoperative deficit presented each a post-operative sensory deficit with in addition a motor trouble in one of cases. We conclude from this survey that there is a risk of peroperative fascicle lesion even when using the microscope. This information is important to consider in the setting of deciding how to proceed before the excision of this benign lesion.

The relationship between pre-operative symptoms, operative findings and postoperative complications in schwannomas

This study presents a retrospective review of the management of schwannomas in the limbs and examines the relationship between pre-operative clinical examination, operative findings and postoperative neurological complications. Eighteen tumours with a histological diagnosis of schwannoma in 17 patients who underwent surgery between 1998 and 2004 were the basis of this study. Enucleation of the tumour was possible in 14 cases. None of these patients had neurological complications pre-operatively but eight had mild neurological complications postoperatively. The complications consisted of sensory deficit in five cases, motor weakness in one and both in two. Enucleation of the tumours was impossible in four cases. These schwannomas originated in the brachial plexus in three cases and the ulnar nerve in the proximal arm in one case. Tumours with pre-operative symptoms and masses located at a proximal site in the limb were more likely to be impossible to enucleate completely.

Schwannoma of the suprascapular nerve presenting with atypical neuralgia: case report and review of the literature

Compressive lesions of the suprascapular nerve produce weakness and atrophy of the supra- and infraspinatus muscles and a poorly defined aching pain along the posterior aspect of the shoulder joint and the adjacent scapula. Entrapment neuropathy of the suprascapular nerve is fairly common whereas tumorous lesions are rare; among the latter ganglion cysts are frequently seen. An isolated solitary schwannoma of the suprascapular nerve presenting with atypical neuralgic pain is exceptional. The location of a schwannoma under the firm deep cervical fascia in the posterior triangle of the neck is implicated in the genesis of neuralgic pains mimicking the suprascapular entrapment syndrome. One such case is reported with discussion of the relevant clinical features.