Parapharyngeal neurilemmomas

Schwannoma in the Supraclavicular Region: Case Report

Schwannomas are benign tumors arising from schwann cells in peripheral, cranial, and autonomic nerve sheaths. Approximately half of all cases of schwannomas are observed in the head and neck region. In this study, a 71-year-old male patient presenting with a stiff mobile mass in the left supraclavicular region and diagnosed as a schwannoma after total excision was presented.

Contrasting radiological presentation of cervical sympathetic chain schwannoma: case series of two cases

Splaying of carotid bifurcation on imaging, known as Lyre sign, is seen characteristically in carotid body tumors. Is positive Lyre sign always confirmatory of carotid body tumor? Here we discuss two cases of cervical sympathetic chain schwannoma. The first case presented radiologically as an enhancing lesion with splaying of external carotid artery and internal carotid artery (positive Lyre sign) and misled us to the diagnosis of carotid body tumor. The second case presented as an enhancing lesion causing anterior displacement of external carotid artery and internal carotid artery (negative Lyre sign). Both lesions were confirmed as cervical sympathetic schwannoma. Post-operatively both patients developed Horner's syndrome. Lyre sign is not always confirmatory of carotid body tumor.

Intrapharyngeal schwannoma in a pediatric patient

Schwannomas are benign peripheral nerve neoplasms that arise from Schwann cells. They usually occur in the adult population. The most common site in the head and neck region is the parapharyngeal space. Intrapharyngeal schwannomas are extremely rare, and those that have been reported all occurred in adults. We report what to the best of our knowledge is the first case of an intrapharyngeal schwannoma in a pediatric patient. The patient, a 15-year-old boy, was treated successfully with surgical excision.

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.

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.

Endoscopic transoral approach for extracranial hypoglossal schwannoma

OBJECTIVE

Hypoglossal nerve schwannoma, especially when inside the extracranial region, is extremely rare. This report describes a new endoscopic transoral approach for the removal of extracranial hypoglossal schwannoma.

PATIENTS AND METHODS

Three patients (1 male and 2 females, aged 58-63 years) with extracranial hypoglossal schwannoma in the paroccipital condyle and the jugular foramen were treated solely by an endoscopic transoral approach. All patients presented signs of hypoglossal nerve paresis with hemiatrophy of the tongue. In addition, one of them had glossopharyngeal nerve paresis, and vagus nerve paresis was found in another patient.

RESULTS

In all patients, tumors underwent successful radical intracapsular removal by the endoscopic transoral approach, as confirmed by the postoperative examinations and MRI. No complications occurred during or after surgery, except that 1 patient had swallowing difficulties and a temporary right vagus palsy during the first day after surgery. All patients were followed up for 6 months, and the lack of any recurrence has been confirmed. Muscle bulk, motor and swallowing functions, and the vagus palsy improved in all patients.

CONCLUSION

The endoscopic transoral approach is a safe and useful surgical technique for the removal of intracapsular tumors, including extracranial hypoglossal schwannomas, which involves minimal invasion.

Hypoglossal schwannoma presenting only with headache

Hypoglossal schwannoma is a rarely encountered skull base lesion that has generally both intracranial and extracranial parts. This article reports a case of hypoglossal schwannoma that is purely extracranial and presents itself only with persistent headache. Magnetic resonance imaging delineated a mass at the skull base that consisted of both cystic and solid components, consistent with a nerve sheath tumor. Cervical approach was chosen, and the mass was completely removed. Postoperatively, the patient developed hypoglossal nerve palsy because the hypoglossal nerve was sacrificed. Hypoglossal schwannomas are briefly discussed with a literature review.

Hypoglossal schwannoma-successful reinnervation and functional recovery of the tongue following tumour removal and nerve grafting

OBJECTIVE

Hypoglossal nerve schwannomas are rare tumours that usually cause ipsilateral hypoglossal palsy. This report describes such lesions in two patients and suggests nerve grafting as part of the treatment regimen.

METHOD

Two patients with intra- and extra-dural hypoglossal schwannomas respectively were treated by direct surgery via a postero-lateral approach to the posterior fossa, hypoglossal canal and carotid sheath. Following tumour removal, sural nerve grafting was used to reconstruct the nerves. Unexpectedly, muscle bulk and motor function returned within 6 months in both patients.

CONCLUSION

Nerve grafting was highly successful in achieving functional recovery following surgery for hypoglossal nerve schwannomas.

Extradural dumbbell schwannoma of the hypoglossal nerve: a case report with review of the literature

BACKGROUND

Dumbbell-shaped schwannomas of the hypoglossal nerve are very rare. This report concerns a case with an extradural, dumbbell-shaped hypoglossal schwannoma extending both intra- and extracranially.

CASE DESCRIPTION

A 25-year-old woman presented with a right hypoglossal palsy. Imaging revealed a dumbbell-shaped tumor with considerable compression and medial displacement of the medulla oblongata, diagnosed as a hypoglossal schwannoma. The tumor mass extended extracranially to the parapharyngeal space through the enlarged hypoglossal canal. The tumor was partially excised by a right far-lateral suboccipital approach and the tumor was found to be predominantly extradural with minimal intradural extension. A histopathologic diagnosis of schwannoma was made.

CONCLUSIONS

This case emphasizes the importance of recognizing this extradural variant of schwannoma. Staged extracranial and intracranial approaches to these tumors may be necessary.

Schwannoma of the Retropharyngeal Space

We report a rare case of schwannoma arising from the retropharyngeal space. A 24-year-old man presented a 2-month-history of a foreign body sensation in the throat and gradually progressing dysphagia when he swallowed solids and liquids. The patient had no odynophagia, fever, or blood in his saliva. Computed tomographic scans and magnetic resonance images revealed a well-defined and oval mass, measuring about 40 mm x 20 mm in size, in the retropharyngeal space. Because the tumor existed in the retropharyngeal space and was the adequate size, the patient underwent trans-oral resection under the direct laryngoscope without the need for skin incision. On the basis of the histological findings, the tumor was diagnosed as a schwannoma. It was mostly composed of spindle cells arranged in short bundles and fascicles, with focal palisading of the nuclei. The neoplasm arising from the retropharyngeal space is quite rare, because of few anatomical structures in the space. The post-operative course was uneventful, and the patient is currently free from disease 30 months after surgery. Diagnosis, clinical behavior, and treatment of retropharyngeal schwannoma are reviewed from perusal of the literature. When schwannomas are located in the pharynx, they may cause foreign body sensation or dysphagia. Therefore, when a foreign body sensation in the larynx is present, a thorough diagnostic procedure should be performed to evaluate the morphology of the upper aerodigestive tract.

Removal of infratemporal fossa schwannoma via a transmandibular transpterygoid approach

Trigeminal schwannomas are commonly located in the intracranium, and extracranial schwannomas limited to the infratemopral fossa (ITF) are extremely rare. Trigeminal mandibular schwannoma was found in the left ITF of a 48-year-old man who presented with a 1-year history of left facial pain and trismus. The schwannoma was completely removed by a transmandibular transpterygoid approach with no major complications. This case is discussed with a review of the literature on this rare occurrence, focusing on the surgical approach.

Extracranial lower cranial nerve sheath tumors

OBJECTIVE

The purpose of this article is to review the clinicoradiographic features of lower cranial nerve sheath tumors and to outline surgical approaches that allow the safe and complete resection of these lesions.

METHODS

Thirteen patients with lower cranial nerve sheath tumors of the infratemporal fossa were surgically treated between 7/88 and 10/99. A retrospective chart analysis provided details pertaining to clinical manifestations, radiographic assessment, intraoperative findings, tumor histology, and postoperative results.

RESULTS

The most common presenting symptoms were neck pressure and voice change while submucosal palatal fullness and vocal cord paralysis were the most common presenting signs. All tumors were removed via lateral skull base approaches and the most common postoperative sequelae was dysphasia.

CONCLUSION

Lower cranial nerve sheath tumors of the infratemporal fossa usually reach considerable size before diagnosis because of a naturally slow growth rate in this relatively silent location. The safe surgical removal of these tumors, based on superior control of the internal carotid artery, can be achieved through the use of contemporary lateral skull base techniques.

A skull base extradural hypoglossal neurilemmoma resected via an extended posterolateral approach

The case of a 43-year-old man with a right skull base hypoglossal neurilemmoma excised via the extended posterolateral approach is presented. There is only one previous case of hypoglossal neurilemmoma in the literature. The surgical technique described is a new approach to the posterior skull base involving a suboccipital craniectomy, mastoidectomy and the removal of the lateral process of the atlas. It provides an inferior approach to the jugular foramen and hypoglossal canal that allows the lower cranial nerves to be identified as they exit from their skull base foramina. In the discussion we compare this technique to other surgical approaches previously described for access to the region of the jugular foramen.

A multifocal schwannoma of the masseteric nerve causing hemicrania

A case is reported of schwannoma of the right masseteric nerve, invading the pterygopalatine fossa and the parapharyngeal space through the mandibular notch in a 61-year-old woman. The tumor in this case was composed of four various-sized interconnected nodules, simulating a string of beads. The tumor was the cause of the patient's chronic hemicrania, as confirmed by the relief from and disappearance of head pain after surgical removal of the tumor. The most important aspects of this case are the anatomic site of the schwannoma and its uncommon clinicopathologic manifestations; this tumor originated from the masseteric nerve and is the first case reported to straddle the mandibular notch.