Results of neurilemoma treatment: a review of 78 cases

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.

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.

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 of the median nerve at the wrist and palmar regions of the hand: a rare case report

Schwannomas are also known as neurolemmas that are usually originated from Schwann cells located in the peripheric nerve sheaths. They are the most common tumours of the hand (0.8-2%). They usually present solitary swelling along the course of the nerve however multiple lesions may be present in cases of NF type 1, familial neurofibromatosis, and sporadic schwannomatosis. Schwannomas are generally represented as an asymptomatic mass; however pain, numbness and fatigue may take place with the increasing size of the tumour. EMG (electromyelography), MRI (magnetic resonance imagination), and USG (ultrasound) are helpful in the diagnosis. Surgical removal is usually curative. In this paper, we present a 24-year-old male referred to our clinic for a lump located at the volar side of the left wrist and a lump located in his left palm and numbness at his 3rd and 4th fingers. Total excision was performed for both lesions. Histopathological examination of the masses revealed typical features of schwannoma. At the 6th-month followup the patient was symptom-free except for slight paresthesia of the 3rd and the 4th fingers. For our knowledge, this is the second case in the literature presenting wrist and palm involvement of the median nerve schwannoma.

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.

Extraaxial neurofibromas versus neurilemmomas: discrimination with MRI

OBJECTIVE

The purpose of our study was to evaluate whether MRI can discriminate between extraaxial neurofibromas and neurilemmomas.

MATERIALS AND METHODS

MR images of 52 patients with a pathologically proven extraaxial neurofibroma or neurilemmoma were retrospectively reviewed by observers who were unaware of the surgical results, regarding the presence or absence of individual imaging criteria. MRI findings in 12 patients with a localized neurofibroma and 40 patients with a neurilemmoma were compared using the chi-square test or Fisher's exact test.

RESULTS

MRI findings suggestive of neurofibroma (p < 0.05) were a target sign on T2-weighted images (58% in neurofibromas vs 15% in neurilemmomas), central enhancement (75% vs 8%), and a combination of both findings (63% vs 3%). MRI findings suggestive of a neurilemmoma (p < 0.05) were a fascicular appearance on T2-weighted images (25% vs 63%), a thin hyperintense rim on T2-weighted images (8% vs 58%), a combination of both findings (8% vs 48%), and diffuse enhancement (13% vs 67%). No significant difference was seen between neurofibromas and neurilemmomas for a centrally entering and exiting nerve (42% in neurofibromas vs 23% in neurilemmomas), a peripherally entering and exiting nerve (58% vs 77%), a cystic area (38% vs 64%), a low-signal margin (100% vs 100%), peripheral enhancement (13% vs 26%), or a target sign on contrast-enhanced images (11% vs 31%).

CONCLUSION

MRI shows features helpful for differentiating extraaxial neurofibromas from neurilemmomas; however, no single finding or combination of findings allows definitive differentiation.