Benign peripheral nerve tumors

Utility of Sodium Fluorescein During Peripheral Nerve Tumor Surgery: A Scoping Review of Indications, Techniques, and Outcomes

OBJECTIVE

The primary treatment for peripheral nerve tumors involves maximal surgical resection while preserving nerve function. Sodium fluorescein shows potential for enhancing the safety and efficacy of nerve tumor surgery. This review evaluates the advantages and limitations of sodium fluorescein in this context.

METHODS

PubMed, EMBASE, Web-of-Science, and Scopus were searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-scoping review guidelines to include studies reporting the use of sodium fluorescein in peripheral nerve tumors surgery. Intervention-related outcomes (i.e., extent of resection, clinical outcomes, complication rates, recurrence rates, and duration of surgery) were evaluated and summarized.

RESULTS

A total of 4 studies encompassing 166 patients with 168 tumors were included. Patients were mostly female (98; 53.6%), 101 (69.2%), had sporadic (nonsyndromic) tumors, and at histopathology, 114 (67.9%) tumors were WHO grade-1 schwannomas. Gross total resection was achieved in 146 (86.9%) tumors. Postoperative complications were reported in 16 cases (10.2%%), none related to side effects of the fluorescent dye. High tumor fluorescence was reported in 150 (94.3%) tumors, while absent and low parent nerve fluorescence was reported in 121 (79.6%) and 27 (17.8%), respectively. The median duration of surgery was 51.5 (range: 24-92) minutes.

CONCLUSIONS

Sodium fluorescein shows promise as assisting tool in nerve tumor surgery by facilitating differentiation among the tumor, parent nerve, and surrounding soft tissue. However, multicenter randomized controlled trials are necessary to determine its effect on extent of resection rates, clinical outcomes, postoperative complication rates, and surgical duration in comparison to current standard of care.

Transoral Endoscopic Excision of Laryngeal Schwannoma

OBJECTIVE

Schwannomas originating within the larynx are rare and there is no clear consensus on the diagnostic workup or treatment. This study aims to explore the clinical features of laryngeal schwannoma and evaluate the surgical method of transoral endoscopic excision, especially with coblation.

METHODS

Data from patients diagnosed with laryngeal schwannoma who underwent surgery at Peking Union Medical College Hospital from 2017 to 2022 were retrospectively analyzed. All cases were evaluated with a flexible laryngoscope and computed tomography and/or magnetic resonance imaging before surgery.

RESULTS

Four patients, comprising one male and three females aged 19 to 61years, were included. All patients presented with persistent and progressive hoarseness, and two also experienced dyspnea on exertion. One patient was a recurrent case who underwent transoral tumor resection with a laser, while another patient had received a transoral incisional biopsy before visiting our hospital. Transoral excision was performed in each case. One tumor was excised using microlaryngeal instruments under a microscope, and the other three with coblation assisted by an operating laryngoscope. All laryngeal schwannomas were removed in a single block. All patients were successfully extubated following surgery, recovered without complications, and showed no evidence of recurrence.

CONCLUSION

Transoral surgery better preserves laryngeal function, reduces complications, and shortens hospital stays. Transoral endoscopic excision, particularly when performed with coblation, is highly recommended for its excellent visualization and ability to completely excise the tumor. This method is a safe and effective approach, especially for large laryngeal schwannomas in hard-to-reach locations.

Giant gluteal and vesical plexiform neurofibromas in a patient with neurofibromatosis type 1: a case report

BACKGROUND

Neurofibromatosis type 1 is a neurocutaneous genetic disorder caused by mutations in the NF1 gene, resulting in the formation of benign tumors called neurofibromas. The most common type of tumor seen in patients with neurofibromatosis type 1 is the slow-growing and benign neurofibroma, with a subtype called plexiform neurofibroma being particularly common and causing pain, functional impairment, and cosmetic disfigurement.

CASE PRESENTATION

We report the case of a 20-year-old North African female patient with a history of neurofibromatosis type 1 who presented with a growing mass in her right gluteal region, which was later diagnosed as a giant cutaneous neurofibroma. Imaging studies revealed infiltration in several regions, including the urinary bladder wall, resulting in significant bilateral hydronephrosis. The patient is currently being monitored, and no excisional procedures are planned.

CONCLUSIONS

Neurofibromatosis type 1 can cause a variety of clinical symptoms, including the development of large plexiform neurofibromas. It is important to closely monitor patients with neurofibromatosis type 1 for the early detection of neurofibromas. Early detection and prompt surgical intervention are essential for preventing complications.

Benign peripheral nerve sheath tumors: an interdisciplinary diagnostic and therapeutic challenge

A benign peripheral nerve sheath tumor (bPNST) is a rare lesion associated with peripheral nerval structures. Symptoms may be heterogeneous, complicating diagnosis finding. Additionally, management concepts of bPNST may vary. In some cases, initial misdiagnosis leads to mistreatment resulting in severe functional deficits and chronic pain syndromes. Therefore, we analyzed patients treated for bPNST in our specialized institution with a primary focus on prior misdiagnosis and possible mistreatment. Patients with bPNSTs (schwannomas, neurofibromas, hybrid nerve sheath tumors, and perineuriomas) treated at the Neurosurgical Department between January 1, 2015, and July 31, 2021, were included. Assessment of demographics, tumor entity, tumor location, symptoms, the interval between the onset of symptoms and surgery, involved medical specialties, and outpatients' treatment, with particular focus on initial misdiagnosis and inappropriate medical treatment, was performed. Eighty-five patients were included in the final analysis with schwannoma being the most prevalent histopathological diagnosis (schwannoma (75.3%, n=64), neurofibroma (12.9%, n=11), hybrid nerve sheath tumor (5.9%, n=5), and perineurioma (5.9%, n=5)). An incorrect primary diagnosis was detected in 44.7% (n=38), leading to suboptimal or insufficient treatment in these cases. Of those, 28.9% (n=11/38) were treated suboptimal, while 18.5% (n=7/38) underwent unnecessary invasive diagnostics. Inappropriate surgery based on prior misdiagnosis, which led to severe neurological deficits in all these cases, was reported in 26.3% (n=10/38). For the first time, our data shows the quantity and impact of incorrect initial diagnosis in bPNST causing a delay in causative treatment or resulting in unnecessary or potentially harmful treatment.

Acute Foot Drop Caused by Intraneural Ganglion Cyst of the Peroneal Nerve: Literature Review and Case Report

BACKGROUND

Foot drop (FD) is characterized by an inability to lift the foot against gravity because of dorsiflexor muscle weakness. The aim of the present study is to report a clinical case of acute non-traumatic FD in patients with peroneal intraneural ganglion, after performing a scoping review on the methodological management of this disease.

METHODS

We performed a review of the literature and reported the case of a 49-year-old man with acute FD caused by an intraneural ganglion cyst of the peroneal nerve.

RESULTS

Out of a total of 201 articles, 3 were suitable for our review beyond our case report. The acute FD caused by peroneal intraneural ganglion can be managed by a careful clinical-instrumental differential diagnosis. A targeted surgery with subsequent rehabilitation produced a satisfactory motor recovery.

CONCLUSIONS

Acute FD requires an appropriate diagnostic-therapeutic framework to identify and effectively treat the causes in order to promote complete recovery.

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.

Giant Neurofibroma of the Left Median Nerve Associated With Damage of the Ipsilateral Distal Radius

A 74-year-old Caucasian woman presented with a large mass on her left distal radius, which had previously caused a fracture of the bone at this site and the palmar site that was treated with external fixation a year ago. The patient did not mention tumor-related family history and other neoplasms before the fracture of the distal radius. She noticed that the gradually growing mass had appeared after the fracture treatment. A thorough evaluation of the lesion confirmed the diagnosis of a large benign neurofibroma with distal radius impairment. The diagnostic and therapeutic procedure included the complete excision of the tumor and a six-week cast immobilization of the radius. On the final follow-up two years postoperatively, her clinical situation was satisfactory with no signs of recurrence. Although rare, isolated benign neurofibromas of enormous sizes are associated with bone damage. In our view, immediate surgical excision is crucial and enables total recovery postoperatively.

Totally Cystic Schwannoma: A Misnomer

BACKGROUND

Although partial cystic degeneration is commonly observed in schwannoma, cases of totally cystic forms have also been reported. A literature review of cases describing totally cystic schwannoma was performed to assess their imaging characteristics.

METHODS

PubMed was queried with the phrases "totally cystic schwannoma," "purely cystic schwannoma," and "completely cystic schwannoma." A total of 19 papers encompassing 22 cases of reported totally cystic schwannoma were included. Patient characteristics, clinical presentation, and reported imaging characteristics were recorded. Computed tomography and magnetic resonance images from the papers were collected and reviewed by a senior musculoskeletal radiologist.

RESULTS

The most frequent presenting location of these lesions was in spinal nerve roots. The interpretations of imaging reported in the papers described a homogeneous lesion that was isointense to slightly hyperintense to cerebrospinal fluid (CSF) on T1-weighted images. On contrast administration, the studies described a thin rim of "ring-like" enhancement around the lesion. Our reinterpretation of the imaging revealed heterogeneous lesions that were hyperintense to CSF on T1-weighted images. Post-contrast images typically demonstrated an irregularly thickened enhancing rim. Most images showed evidence of solid components in the lesion, with many containing enhancing soft tissue elements. The observed imaging features were not consistent with simple cystic lesions.

CONCLUSIONS

Review of the imaging studies of the reported cases of completely cystic schwannoma did not produce any convincing examples of purely cystic lesions. The description of these lesions as "totally cystic" appears to be a misnomer and has diagnostic and therapeutic implications.

Intraneural ganglion cysts of the peroneal nerve

BACKGROUND

Intraneural ganglion cysts of the peroneal nerve are rare, and there is lack of evidence for the surgical management of this entity. We performed this study to evaluate the imaging, diagnosis, treatment and outcome of seven patients with intraneural ganglion cysts of the peroneal nerve.

MATERIALS AND METHODS

We retrospectively studied the files of seven patients with intraneural ganglion cysts of the peroneal nerve, diagnosed and treated from 2016 to 2019. Diagnostic approach included clinical examination of the leg and foot, magnetic resonance imaging, nerve conduction studies, surgical excision of the cyst and histological examination. The mean follow-up was 2 years (range 1-3.5 years). We evaluated the time and methods for surgical treatment, and the clinical outcomes of the patients.

RESULTS

All patients presented symptoms of peripheral compression neuropathy; three patients presented with foot drop. The intraneural ganglion cysts were excised in all cases in addition to knee articular nerve branch transection to avoid cysts recurrence. Postoperatively, all patients experienced complete neurological recovery without clinical evidence of intraneural ganglion cysts recurrences.

CONCLUSION

The treating physicians should be aware of intraneural ganglion cysts of the peroneal nerve in patients presenting with limb weakness, sensory deficits at the lateral and anterior side of the leg and foot, paresis or paralysis of the foot and ankle. MR imaging is the imaging modality of choice for a clear and accurate preoperative diagnosis to avoid misdiagnosis and wrong treatment. In case of doubt, these patients should be managed in an orthopedic oncology setting with microsurgery facilities available for complete excision of the intraneural ganglion cyst.