Extracranial cephalic schwannomas: a series of 15 patients

A Review of Microsurgical Resection of Recurrent Laryngeal Neurilemmoma Under Nerve Monitoring

BACKGROUND

Laryngeal neurilemmoma, especially recurrent laryngeal neurilemmoma, is a rare neural sheath tumor in head and neck. The most common symptom of laryngeal neurilemmoma is hoarseness or dysphonia, followed by dysphagia, dyspnea, and foreign body sensation. At present, surgical resection is the most effective treatment for this kind of tumor, thus making how to remove it become the most concerned problem of surgeons.

CASE PRESENTATION

On February 18, 2021, a 64-year-old male presented to our clinic with recurrent sore throat and intermittent hoarseness for 3 years. The results of electronic laryngoscope and magnetic resonance imaging showed a 25×10×21 mm well-defined tumor in the left pyriform sinus without laryngeal cartilage destruction and enlarged lymph nodes. After the initial diagnosis of recurrent laryngeal neurilemmoma, to preserve the continuity of recurrent laryngeal nerve as much as possible, the authors determine to perform anatomical resection of recurrent laryngeal neurilemmoma with operating microscope under the monitoring of recurrent laryngeal nerve function. Finally, the patient recovered completely from hoarseness during postoperative follow-up.

CONCLUSION

A complete diagnosis and treatment process of recurrent laryngeal neurilemmoma was presented by the case. Particularly, it shows the application of recurrent laryngeal nerve monitoring in the operation helps to protect the continuity of the recurrent laryngeal nerve, which lays a anatomical bases for the follow-up nerve repair.

Management of parapharyngeal space tumors with transparotid-transcervical approach: analysis of prognostic factors related with disease-control and functional outcomes

PURPOSE

Different therapeutic strategies have been developed to improve surgical and functional outcome of parapharyngeal space (PPS) neoplasms. The transparotid-transcervical approach (TTa) is a valid surgical option to manage most PPS tumors. Its short- and long-term disease control and cranial nerve (c.n.) function outcomes have not been discussed extensively.

METHODS

All patients who underwent TTa over a 10-year period at a tertiary academic center were retrospectively reviewed. Data about preoperative imaging, clinical presentation, tumor's size, location and histology, and postoperative oncological and functional results were registered and analyzed.

RESULTS

Sixty patients matched the inclusion criteria. Most of the lesions were benign (71.7%), involved the prestyloid PPS (63.3%) and measured more than 30 mm (75%). Fifty-two (86.7%) lesions were resected en-bloc. Clear margins were achieved in 91.7% of the cases, with positive margins solely associated with malignancy (p = 0.008). Post-operative c.n. function was satisfactory, with X c.n. function significantly associated with the retrostyloid location (p = .00) and neurogenic tumors (p = 0.02). Local disease-control was achieved in 96% of the cases after a median follow-up of 46 (± 19.7-82.0 IQR) months.

CONCLUSIONS

The TTa was safe and effective, achieving a satisfactory local control rate. Nevertheless, malignancies maintain a higher rate of positive margin due to their infiltrative nature and the complex anatomy of the PPS. In such cases, multiportal approaches might be more effective. However, post-operative c.n. function remained satisfactory, irrespective of lesions' size and histopathologic behavior. A higher X c.n. deficit rate was observed in retrostyloid and neurogenic lesions.

Comprehensive review of surgical microscopes: technology development and medical applications

SIGNIFICANCE

Surgical microscopes provide adjustable magnification, bright illumination, and clear visualization of the surgical field and have been increasingly used in operating rooms. State-of-the-art surgical microscopes are integrated with various imaging modalities, such as optical coherence tomography (OCT), fluorescence imaging, and augmented reality (AR) for image-guided surgery.

AIM

This comprehensive review is based on the literature of over 500 papers that cover the technology development and applications of surgical microscopy over the past century. The aim of this review is threefold: (i) providing a comprehensive technical overview of surgical microscopes, (ii) providing critical references for microscope selection and system development, and (iii) providing an overview of various medical applications.

APPROACH

More than 500 references were collected and reviewed. A timeline of important milestones during the evolution of surgical microscope is provided in this study. An in-depth technical overview of the optical system, mechanical system, illumination, visualization, and integration with advanced imaging modalities is provided. Various medical applications of surgical microscopes in neurosurgery and spine surgery, ophthalmic surgery, ear-nose-throat (ENT) surgery, endodontics, and plastic and reconstructive surgery are described.

RESULTS

Surgical microscopy has been significantly advanced in the technical aspects of high-end optics, bright and shadow-free illumination, stable and flexible mechanical design, and versatile visualization. New imaging modalities, such as hyperspectral imaging, OCT, fluorescence imaging, photoacoustic microscopy, and laser speckle contrast imaging, are being integrated with surgical microscopes. Advanced visualization and AR are being added to surgical microscopes as new features that are changing clinical practices in the operating room.

CONCLUSIONS

The combination of new imaging technologies and surgical microscopy will enable surgeons to perform challenging procedures and improve surgical outcomes. With advanced visualization and improved ergonomics, the surgical microscope has become a powerful tool in neurosurgery, spinal, ENT, ophthalmic, plastic and reconstructive surgeries.

Intraparotid facial nerve schwannoma: two case reports and a review of the literature

SUMMARY

Schwannomas are rare benign tumours that arise from Schwann cells. The most known and studied is the intracranial vestibular schwannoma, even if it is not the most frequent. More often schwannomas arise from peripheral sensitive nerves, and the vagous is most involved among the cranial nerves. Intraparotid schwannomas account for just 10% of all facial involvement, so they are an extremely rare localisation. At present, there are less than 100 cases described in the literature. We performed a retrospective analysis of parotidectomy in two Italian hospitals and present two cases of intraparotid schwannoma and a review of the literature. In the first case, we performed a parotidectomy with a stripping of tumour from the nerve. In the other case, a hypoglossal-facial neurorrhaphy was performed. Follow-up was 24 months in the first (House-Brackmann II degree in temporal-ocular and III in facial-cervical branches) and 30 months in the second case (House-Brackmann III degree in both temporal-ocular and facial-cervical branches). Preoperative diagnosis of facial nerve schwannoma is a challenge; however, it is extremely important since post-operative palsy is common and often higher grade. Unfortunately, schwannoma has similar radiologic finding as more common pleomorphic adenoma and often FNAC is not helpful. Due to its rarity and benign nature, there is debate in the literature on the need for surgical removal. Wait-and-see is a valid option, but may could give problems in secondary surgery. Stripping or near-total removal can be useful in cases of limited involvement of the nerve. Neurorrhaphy can provide good functional results when facial sacrifice is needed.

Contemporary management of primary parapharyngeal space tumors

The parapharyngeal space is a complex anatomical area. Primary parapharyngeal tumors are rare tumors and 80% of them are benign. A variety of tumor types can develop in this location; most common are salivary gland neoplasm and neurogenic tumors. The management of these tumors has improved greatly owing to the developments in imaging techniques, surgery, and radiotherapy. Most tumors can be removed with a low rate of complications and recurrence. The transcervical approach is the most frequently used. In some cases, minimally invasive approaches may be used alone or in combination with a limited transcervical route, allowing large tumors to be removed by reducing morbidity of expanded approaches. An adequate knowledge of the anatomy and a careful surgical plan is essential to tailor management according to the patient and the tumor. The purpose of the present review was to update current aspects of knowledge related to this more challenging area of tumor occurrence.

Subcutaneous Schwannoma in the Head Region

Schwannoma is a benign neural tumor derived from Schwann cells surrounding the nerves. It occurs primarily in subcutaneous tissues and muscles with a tendency for distal extremities, head, and neck area. Treatment of schwannoma is surgical excision. Lipomas are the most common soft-tissue lesions. A case is presented to increase awareness on differential diagnosis of head and neck subcutaneous masses.

Extracranial Trigeminal Schwannomas: A Retrospective Analysis

OBJECTIVE

To analyse the clinic-radiological features and treatment outcome of extracranial trigeminal schwannomas.

METHOD

Medical records and radiographs of patients treated, from January 2011 to December 2013, for neurogenic tumors were retrospectively reviewed. Extracranial schwannomas other than those of trigeminal nerve were also excluded. A number of parameters, including the patient's age, gender, site, clinical features, radiographic features, histologic variants and treatment provided as well as any associated complications were recorded and analysed.

RESULT

A total of 5 patients met the inclusion criteria. The patients were males, aged 16-56 years. All the schwannomas appear to originate from the terminal branches of trigeminal nerve.

CONCLUSION

Long standing asymptomatic swelling of cheek should include trigeminal schwannomas as the differential diagnosis. The diagnosis though confirmed by the histologic examination but can also be made on the basis of MRI finding. Neural function can be preserved by meticulous surgery.

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

OBJECT

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A rare occurrence of intramasseteric schwannoma - case report and literature review

A schwannoma is a benign, solitary, well-defined, painless, slowly-enlarging nerve sheath tumor, composed of Schwann cells. Intramasseteric localization is very unusual. We report the case of a 33-year-old male who developed an intramasseteric schwannoma. Tumor could be completely removed under general anesthesia. Histopathological examination made the diagnosis of intramasseteric schwannoma through the presence of Antoni A areas and Verocay bodies. The diagnosis of schwannoma should be taken into consideration in case of parotideomasseteric tumors.

Laryngeal schwannoma: a systematic review

A large proportion of schwannomas are found in the head and neck region. Schwannoma located within the larynx however is uncommon. The characteristic features, clinical presentations, treatment and the outcomes of patients with laryngeal schwannoma are therefore not clearly understood. The aim of this comprehensive review is to compile, analyze and present the details to develop a consensus and augment the available literature on laryngeal schwannoma. A comprehensive literature search on laryngeal schwannoma was performed on PUBMED/MEDLINE, EMBASE, CINAHL and Science Citation Index using MeSH words. A total of 55 patients were reviewed in this study. 40.7 % of the tumours arose from the aryepiglottic fold or arytenoids. Other areas where tumours were found included the false cord, true vocal cord, epiglottis, subglottis, piriform sinus and the post cricoid area. 64.9 % patients presented with dysphonia. Others typically present with multiple symptoms related to the mass effect and location of the tumour. All patients were managed surgically with different techniques and approaches. Majority of patients were alive with no residual disease. There were five recurrences and no mortality to date. Schwannoma within the larynx can present with a variety of symptoms. Surgical excision remained as the treatment of choice with good overall prognosis.

Schwannoma of the submandibular gland: a case report

Introduction

Schwannoma is a benign, solitary, and slowly progressive encapsulated tumor originating from the sheath of myelinated nerve fibers. Schwannoma of the salivary gland is a particularly rare form of an extracranial neurogenic tumor. Here, we present an unusual case of a schwannoma of the submandibular gland in a 19-year-old man. Total excision of the submandibular gland resulted in complete resolution of symptoms with no cranial nerve deficits. The details of the histopathologic and immunohistochemical features are presented.

Case presentation

A 19-year-old Caucasian man was admitted to our clinic with a painless mass on the right side of his neck that he had had for the past four months. A neck examination revealed a smooth-surfaced, mobile, firm, and painless mass, 6cm in its greatest diameter, on the right side of the submandibular region. Fine-needle aspiration cytology was suggestive of a submandibular gland schwannoma. After the initial evaluation, our patient was prepared for surgical evaluation and resection with a presumptive diagnosis of a neurogenic tumor of the submandibular gland. The final diagnosis of schwannoma was verified by microscopic and immunohistochemical studies. At one-year follow-up of the case, there was no evidence of recurrence.

Conclusions

Schwannoma of the salivary gland is a particularly rare form of an extracranial neurogenic tumor. Our findings indicate good prognosis in an unusual case of a submandibular gland schwannoma in a 19-year-old man treated by surgical excision with no recurrence within 12 months of follow-up.

Nerve-sparing subcapsular resection of head and neck schwannomas: technique evaluation and literature review

Background:

The head and neck region harbours crucial structures and hence the surgical technique used to remove schwannomas from this region should cause minimal damage to these structures, with complete removal of pathology.

Methods:

This study entailed a retrospective analysis of 10 patients with head and neck schwannomas that were excised using a nerve-sparing subcapsular dissection technique. The primary aims were to assess the functional impact of the surgical technique on the structure of origin and to evaluate local control.

Results:

One patient with parapharyngeal schwannoma developed symptoms suggestive of ‘first bite syndrome’ in the late post-operative period. Another patient with facial nerve schwannoma had House–Brackmann grade II weakness in the immediate post-operative period, which subsequently resolved. None of the patients developed recurrence during a median follow-up period of two years.

Conclusion:

The nerve-sparing subcapsular dissection technique provided effective local control of tumour pathology, with relative preservation of neural function post-operatively.

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.

Enucleation of vagal nerve schwannoma using intraoperative nerve monitoring

Vagal nerve schwannomas are rare, benign, neural sheath tumors. The treatment of enlarging or symptomatic vagal nerve schwannomas is surgical resection. Transecting the vagus nerve results in significant morbidity, and attempts at nerve preservation should be made whenever possible. We introduce a nerve-sparing technique using meticulous microsurgical dissection and intraoperative nerve monitoring for vagal schwannomas. A 61-year old patient presented with an enlarging 2-cm right vagal nerve schwannoma. She underwent resection via a transcervical approach. The patient was intubated with an electromyographic (EMG) endotracheal tube that allowed for monitoring of the recurrent laryngeal nerve intraoperatively. A microsurgical subcapsular dissection was performed after branches of the vagus nerve were identified using a nerve probe and preserved. At the conclusion of the resection the nerve was intact and stimulated along its entire course. Postoperatively, the patient had normal vagal nerve function. We introduced the role of intraoperative nerve monitoring using an EMG endotracheal tube for successful enucleation of vagal schwannomas. In conjunction with meticulous microsurgical dissection, nerve monitoring allows for successful preservation of the vagus nerve and decreased postoperative morbidity.

Neck nerve trunks schwannomas: clinical features and postoperative neurologic outcome

OBJECTIVES/HYPOTHESIS

To analyze clinical and epidemiological features of neck nerve schwannomas, with emphasis on the neurologic outcome after surgical excision sparing as much of nerve fibers as possible with enucleation technique.

STUDY DESIGN

Retrospective study.

METHODS

Review of medical records from 1987 to 2006 of patients with neck nerve schwannomas, treated in a single institution.

RESULTS

Twenty-two patients were identified. Gender distribution was equal and age ranged from 15 to 61 years (mean: 38.6 years). Seven vagal, four brachial plexus, four sympathetic trunk, three cervical plexus, and two lesions on other sites could be identified. Most common symptom was neck mass. Local or irradiated pain also occurred in five cases. Median growing rate of tumors was 3 mm per year. Nerve paralysis was noted twice (a vagal schwannoma and a hypoglossal paralysis compressed by a vagal schwannoma). Different techniques were employed, and seven out of nine patients kept their nerve function (78%) after enucleation. No recurrence was observed in follow-up.

CONCLUSIONS

Schwannomas should be treated surgically because of its growing potential, leading to local and neural compression symptoms. When possible, enucleation, which was employed in 10 patients of this series, is the recommended surgical option, allowing neural function preservation or restoration in most instances. This is especially important in the head and neck, where denervation may have a significant impact on the quality of life.

Extracranial Non-vestibular Head and Neck Schwannomas: A Ten-year Experience

Introduction: We present a series of head and neck extracranial non-vestibular schwannomas treated during a ten-year period, assessing epidemiology, presenting signs and symptoms, location, nerve of origin, diagnostic modalities, treatment and clinical outcome. Materials and Methods: Clinical records of all patients with head and neck schwannomas treated at our department from April 1995 to July 2005 were retrospectively reviewed. Results: There was female predominance (67%). The mean age at diagnosis was 48 years. Sixteen (76%) presented with a unilateral neck mass. Eleven schwannomas (52%) were in the parapharyngeal space. The most common nerves of origin were the vagus and the cervical sympathetic chain. The tumour may masquerade as a cervical lymph node and other myriad conditions. Treatment for all but 2 cases was complete excision with nerve preservation. Two cases of facial schwannoma required sacrifice of the affected nerve portion with nerve reconstruction. All facial schwannoma patients suffered postoperative facial palsy with only partial resolution (mean final House-Brackman grade, 3.25/6). Among non-facial schwannoma patients, postoperative neural deficit occurred in 12 with partial to complete resolution in 7. The median follow-up period was 24 months. No schwannoma was malignant and none recurred. Conclusion: Non-vestibular extracranial head and neck schwannomas most frequently present as an innocuous longstanding unilateral parapharyngeal neck mass. Preoperative diagnosis may be aided by fine-needle cytology and magnetic resonance imaging or computed tomographic imaging. The mainstay of treatment is complete intracapsular excision preserving the nerve of origin, but for extensive tumour or facial schwannomas, subtotal resection or nerve sacrifice with reconstruction and rehabilitation are considerations. Surgery on intraparotid facial schwannomas carries considerable morbidity and conservative management has a place in treatment. Early recognition of facial schwannomas is key to optimal treatment. Key words: Asian, Extracranial non-vestibular, Head and neck schwannomas, Single institution

Extracranial Head and Neck Schwannomas: A Clinical Analysis of 33 Patients

OBJECTIVE

To study the clinical features, diagnosis, and management of the extracranial head and neck schwannomas.

STUDY DESIGN

Retrospective study.

METHODS

The clinical data of 33 patients with schwannoma of the head and neck from 1996 to 2006 were studied retrospectively.

RESULTS

Extracranial head and neck schwannomas usually presented as solitary and well-demarcated lesions with insidious course. Although benign, the lesion can cause secondary symptoms, such as nasal obstruction, dysphasia, and hoarseness, relevant to location of the lesion. Fine needle aspiration cytology, computed tomography scans, and magnetic resonance imaging may provide limited implications in the diagnosis of schwannomas, whereas postoperative pathologic examination establishes the final diagnosis.

CONCLUSIONS

Complete surgical excisions with appropriate approaches have proven to be efficient and successful in the treatment of head and neck schwannomas.

Schwannoma originating from the infraorbital nerve: A case report

A 16-year-old female admitted to otolaryngology outpatient clinic with the complaints of pain and replacement of her left eyeball upwards. Radiological imaging demonstrated a solid mass inferior to the left globe. The anterior wall of the maxilla was thinned and the mass pushed the orbital floor inferiorly. Following subciliary incision, the bone over the mass was removed from the orbital rim and the mass was exposed. The mass originated from the infraorbital nerve. The mass was excised and the orbital rim, malar region and the orbital floor were reconstructed by a titanium mesh. The histopathological report was "schwannoma". Seven cases of schwannomas arising from the infraorbital nerve reported in English literature. In this paper we report a case of infraorbital schwannoma and review the literature.

Extracranial head and neck schwannomas: a review of 8 years experience

Schwannomas of the head and neck are uncommon tumors that arise from cranial, peripheral or autonomic nerves. In this study we review a series of 52 cases of schwannoma originating in the head and neck region over an 8-year period. All the tumors were benign, with the exception of one malignant schwannoma. The age range of the patients studied was 13-76 years and there was a predilection for males. Twenty-five schwannomas occurred in the scalp, face and external ear canal, 9 in the oral or nasal cavity and 18 in the neck. Seven cases of neck schwannoma originating from the major nerve system were found in the parapharyngeal space, all of which were located in the post-styloid compartment. Cervical plexus schwannomas originated either in the peripheral nerves or in an unidentified area of the nervous system; seven tumors were found in the posterior triangle of the neck and two in the anterior triangle. Two of the tumors originating in the brachial plexus were located in the posterior neck and one in the anterior neck. Tumors originating in the vagus nerve or sympathetic chain were all located in the anterior triangle of the neck.

[Mandibular trigeminal schwannoma: case report]

We report one case of peripheral trigeminal schwannoma originated from the mandibular branch (V3) and located inside the infratemporal and pterygopalatine fossae with slight intracranial extension. The tumor was completely removed by a transmaxillary approach. The revision of the literature showed to be a very rare tumor in this location.