Hypoglossal schwannoma in the submandibular space

Management of non-vestibular schwannomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section Part III: Lower cranial nerve schwannomas, jugular foramen (CN IX, X, XI) and hypoglossal schwannoma (XII)

BACKGROUND

Non-vestibular schwannomas are relatively rare, with trigeminal and jugular foramen schwannomas being the most common. This is a heterogenous group which requires detailed investigation and careful consideration to management strategy. The optimal management for these tumours remains unclear, and there are several controversies. The aim of this paper is to provide insight into the main principles defining management and surgical strategy, in order to formulate a series of recommendations.

METHODS

A task force was created by the EANS skull base section committee along with its members and other renowned experts in the field to generate recommendations for the surgical management of these tumours on a European perspective. To achieve this, the task force performed an extensive systematic review in this field and had discussions within the group. This article is the third of a three-part series describing non-vestibular schwannomas (IX, X, XI, XII).

RESULTS

A summary of literature evidence was proposed after discussion within the EANS skull base section. The constituted task force dealt with the practice patterns that exist with respect to preoperative radiological investigations, ophthalmological assessments, optimal surgical and radiotherapy strategies and follow-up management.

CONCLUSION

This article represents the consensually derived opinion of the task force with respect to the treatment of non-vestibular schwannomas. For each of these tumours, the management paradigm is shifting towards the compromise between function preservation and progression free survival.

A clinical study of submandibular schwannoma

OBJECTIVE

Schwannoma is a slowly growing benign neurogenic tumor that develops from the cells of the nerve sheath. The occurrence of schwannoma in the submandibular space is very rare.

MATERIALS AND METHODS

From January 2010 to March 2021, we reviewed all patients who had been operated on in the otolaryngology department over 11 years and found 61 patients diagnosed with schwannomas at the final biopsy after surgery. In these patients, only 3 submandibular schwannomas were identified, and their clinical characteristics were analyzed.

RESULTS

Three schwannomas (4.9%) developed in the submandibular space. The main symptoms were neck swelling followed by neck discomfort. All submandibular schwannomas were removed surgically with a transcervical approach under general anesthesia. Two patients, who were diagnosed preoperative submandibular tumors, were considered to have developed schwannomas from the lingual nerve, and 1 patient was considered to have developed a schwannoma from the hypoglossal nerve. There were no major surgical complications, including postoperative nerve damage.

CONCLUSIONS

Submandibular schwannomas are extremely rare, but they should be included in the differential diagnosis of submandibular tumors.

Hypoglossal schwannomas: A systematic review of the literature

BACKGROUND

Schwannomas of the hypoglossal nerve are rare and account for a very small percentage of non-vestibular schwannomas.

OBJECTIVES

In this systematic review of the literature, we examined the epidemiology, symptomatology, management, and outcomes of patients with hypoglossal schwannomas.

METHODS

The electronic database Pubmed was searched for all reports of hypoglossal schwannomas with descriptions of symptoms, management, and outcome characteristics. Data was extracted from each study and compiled in a spreadsheet. Continuous variables were reported as means and medians. Categorical variables were reported as proportions. Additional analysis was not done due to inconsistent reporting of outcomes and small sample sizes.

RESULTS

A total of 59 studies (94 total individual cases) were included. 64% of patients were female with mean age of 44.6 years. The majority were intracranial/extracranial (50%). The most common symptoms were tongue deviation or speech disturbance (38%) and headaches (33%). Hypoglossal nerve dysfunction was present in 80% of patients. Surgical excision was performed in 93%, with a 15% complication rate. Evidence of residual mass after surgery was noted in 29%. Permanent hypoglossal nerve deficits occurred in 67%. Recurrence of tumor burden was reported in 6 studies, with median time to recurrence of 16.5 months.

CONCLUSION

Current evidence suggests overall favorable outcomes with surgical resection of hypoglossal schwannomas, with a large percentage of patients experiencing mild and usually well-tolerated neurologic deficit. Limitations of this study include the use of retrospective data taken from case reports/series with highly selected patients, selective reporting, and absence of control groups.

Schwannoma With Cystic Changes in the Pterygomandibular Space

Schwannomas are tumors that arise from Schwann cells. Although schwannomas can occur almost anywhere in the body where nerve cells are present, they rarely occur in the head and neck region, including the oral and maxillofacial region. Cystic changes in schwannomas are extremely rare. This report is on a case of schwannoma with cystic changes that occurred in the pterygomandibular space.A 46-year-old woman presented with a complaint of limited mouth opening and pain on the left side of the mandible for 3 months. On panoramic radiography, radiolucency was seen on the left mandibular ramus. On enhanced computed tomography, a 4 × 3 cm cystic mass was found along the inner side of the left mandibular ramus area. Magnetic resonance imaging showed a multiseptated, well-demarcated cystic lesion on the inner side of the mandibular ramus on the left side. Under general anesthesia, the tumor was excised. The final diagnosis was schwannoma with cystic changes. Lower lip hypoesthesia occurred postoperatively. At the 1-year postoperative follow-up, maximum mouth opening was increased to 44 mm, and lip hypoesthesia was improved.

Management of hypoglossal schwannomas: single institutional experience of 14 cases

Background Hypoglossal schwannomas are rare intracranial neoplasms. Microsurgical resection with the goal of cure is the aim of management but is associated with a high rate of postoperative morbidity. Objective The objective of the study was to outline the clinical presentation, radiologic characteristics, surgical techniques, postoperative morbidity, and long-term follow-up results for hypoglossal schwannomas. Methods Patients treated for hypoglossal schwannoma at the Department of Neurosurgery of a tertiary-level referral institution from January 2001 until December 2010 were analyzed retrospectively using hospital records. Results There were 14 patients who were treated in the study period. Tongue atrophy and swallowing difficulties were the most common presenting symptoms. Surgery done in 12 patients using a variety of approaches (retromastoid retrosigmoid suboccipital in 9, midline suboccipital in 2, and far lateral in 1). Five patients having small residual tumors received gamma knife (GK) subsequently. two patients received primary GK stereotactic radiosurgery. Three patients had permanent morbidity in the form of cranial nerve paresis. Immediate postoperative complications like cerebrospinal fluid leak and pneumonia were present in three patients. Conclusion Complete microsurgical resection is often associated with a high rate of morbidity. Subtotal and near-total resection followed by stereotactic radiosurgery or observation now offers an alternative approach.

Plexiform hypoglossal schwannoma of the tongue and the submandibular region

Hypoglossal schwannomas usually develop in the intracranial portion of the brain. Incidence of hypoglossal schwannomas of the submandibular region is extremely rare. A 27-year-old patient presented to us with hypoglossal schwannoma of the tongue and the submandibular region. The tumor was excised intraorally combined with submandibular approach. Histopathologic examination revealed a plexiform schwannoma (a rare variant).

Microsurgical management of hypoglossal schwannomas over 3 decades: a modified grading scale to guide surgical approach

BACKGROUND

Schwannomas originating from the hypoglossal nerve are extremely rare. Microsurgical resection with the goal for cure has traditionally been associated with a high risk of postoperative deficits.

OBJECTIVE

To summarize our clinical experience using tailored cranial base approaches for these formidable lesions.

METHODS

The clinical records of 13 patients were retrospectively reviewed. In addition, all reported patients in the literature were reviewed. The extreme lateral infrajugular transcondylar-transtubercular exposure approach was used in all of our patients. Based on our experience and literature analysis, we propose the following modified grading scale to facilitate surgical planning: type A, intradural tumors; type B, dumbbell-shaped tumors; type C, extracranial tumors; and type D, peripheral tumors.

RESULTS

All 13 patients underwent total, near-total, or subtotal tumor resection. Eight patients were men, 5 were women (mean age, 41.7 years). Sural nerve graft reconstruction for the hypoglossal nerve was performed in 4 patients. Three of the 4 patients in whom nerve reconstruction was performed regained satisfactory movement of their tongue. In the review of the literature, the mean patient age was 45.8 years. Patients presented with tongue atrophy (91.6%), headache (60.9%), and dysphagia (31.8%). The tumors were categorized as type A in 31.7% of these patients, type B in 38.6%, type C in 6.2%, and type D in 23.4%.

CONCLUSION

The extreme lateral infrajugular transcondylar-transtubercular exposure approach, which is a modification of the extreme lateral suboccipital approach, provides sufficient exposure for most intracranial dumbbell-shaped hypoglossal schwannomas. Hypoglossal nerve reconstruction using a sural nerve graft improves tongue atrophy and movement for patients with resected nerves.

Endoscopic endonasal clipping of a ruptured vertebral-posterior inferior cerebellar artery aneurysm: technical case report

BACKGROUND AND IMPORTANCE

Aneurysms arising from the vertebral and posterior inferior cerebellar artery complex account for only 0.5 to 3% of all aneurysms. Surgery for these aneurysms is technically challenging because of the deep location and intimate relation with the medulla and lower cranial nerves. The authors report the case of a patient with a right vertebral-posterior inferior cerebellar artery complex (VA-PICA) aneurysm that was successfully clipped via an extended endoscopic endonasal transclival approach.

CLINICAL PRESENTATION

A 74-year-old woman with the sudden onset of severe headache, nausea, and vomiting was admitted to our hospital. A computed tomography (CT) of the brain revealed diffuse subarachnoid hemorrhage associated with intraventricular hemorrhage and incipient hydrocephalus. Cerebral angiography revealed a 1.2-mm aneurysm arising at the origin of the right PICA. The aneurysm was considered unsuitable for selective coil embolization, so neck clipping was performed. With the use of an extended endoscopic endonasal transclival approach, the aneurysm was accurately reached endoscopically and successfully clipped from the parent artery. The patient was discharged neurologically intact.

CONCLUSION

To the best of the authors' knowledge, this is the first report of a successfully treated VA-PICA ruptured aneurysm using a pure endoscopic endonasal transclival approach. Endoscopic surgery may be added to the armamentarium of procedures for the treatment of posterior circulation aneurysms.

A cylindrical extracranial cranial base neurinoma of the hypoglossal nerve: a rare tumor with a rare localization: case report

OBJECTIVE

Neurinomas of the hypoglossal nerve are very rare. They are mostly located intracranially or combined intra- and extracranially, resulting in the so-called dumbbell shape. The isolated extracranial localization of the neurinoma of the hypoglossal nerve adjacent to the cranial base as described in this case report is extremely rare.

CLINICAL PRESENTATION

The 23-year-old patient presented with recurring headaches. She had right-sided hypoglossal nerve palsy for approximately 5 to 6 years. Magnetic resonance imaging revealed an extracranial tumor with contact to the cranial base originating from the hypoglossal nerve.

INTERVENTION

The tumor was extirpated surgically and verified histologically as a schwannoma of the hypoglossal nerve.

CONCLUSION

Pathologies of the hypoglossal nerve as such are very rare within the clinical landscape. When a tumor occurs, its shape and location must be analyzed to establish whether, or by which approach, surgical removal is feasible. Although very unusual, the mere extracranial occurrence of a hypoglossal neurinoma at the cranial base should be considered a differential diagnosis.

Neurinoma of the hypoglossal nerve in the submandibular space: case report and review of the literature

Neurinomas of the hypoglossal nerve extending extra-cranially are rare; a schwannoma in a 63-year-old woman causing nerve palsy is reported. The tumour presented as a slow-growing mass in the right submandibular space; a surgical approach with transcervical exploration was performed. The post-operative course was uneventful.

Usefulness of transcervical approach for surgical treatment of hypoglossal schwannoma with paraspinal extension: case report

BACKGROUND

Usefulness of transcervical approach to hypoglossal schwannoma with paraspinal extension is described herein.

CASE DESCRIPTION

A 54-year-old woman presented with gradually worsening left hypoglossal nerve palsy. The findings were of a tumor lying in the left hypoglossal canal and paraspinal region and were consistent with hypoglossal schwannoma. Subtotal intracapsular removal of the tumor was performed via transcervical approach. The symptoms improved, and no additional symptoms were noted.

CONCLUSION

The transcervical approach and intracapsular removal of the tumor under electrophysiological monitoring provided for successful minimally invasive surgery in this case of hypoglossal schwannoma.

Two cases of schwannoma with marked cystic changes

We report two cases of schwannoma displaying marked cystic changes; one in the temporalis muscle and one in the submandibular space. The first patient, a 44-year-old male, presented after complaining of a swelling rapidly increasing in size in the left temporal region. Computed tomography (CT) indicated a low-density area surrounded by soft tissue. Magnetic resonance imaging (MRI) revealed signal hypointensity on T1 weighted imaging and strong signal hyperintensity on T2 weighted imaging. The extirpated tumour specimen measured 58 mm x 58 mm x 30 mm. Histopathological examination identified schwannoma, comprising spindle cell proliferation in a palisading pattern with obvious cystic changes. The second case involved a 46-year-old female who presented with swelling of the right submandibular region. Panoramic radiography and lateral oblique mandible projection, which were used together with conventional sialography of the submandibular gland, revealed the so-called "ball in hand" appearance of the submandibular gland, and contrast-enhanced CT identified a lesion of 30 mm diameter with a well-defined annular margin and homogeneous low-density near the tumour centre. Benign pleomorphic adenoma was suspected, but histopathological examination identified schwannoma, predominantly comprising Antoni B type tissue.

Schwannoma in the sublingual space

In this report, we present CT and MRI findings of a case of a schwannoma that developed in the floor of the oral cavity. A 49-year-old woman visited our hospital with a painless swelling in the oral floor. CT and MRI revealed a well circumscribed oval mass in the sublingual space, which showed cystic degeneration in most of the lesion. In addition, a thickened wall that strongly enhanced after injection of contrast medium and formation of fluid level were observed in the mass. The mass was removed and was histopathologically diagnosed as schwannoma. Only a few cases of schwannoma in the oral floor have been reported. However, when the characteristic findings are observed on CT and MRI, schwannoma should be added to the differential diagnosis.