Intracapsular enucleation of vagus nerve-originated tumors for preservation of neural function

Asymptomatic Case of Cervical Vagal Schwannoma

Schwannomas are benign, slow-growing, and encapsulated tumors deriving from the perineural cells located in the nerve sheath. They can arise from any peripheral, cranial, or autonomic nerves and show a predilection for the head and neck region. Extracranial head and neck schwannomas are rare tumors. They may produce secondary symptoms such as nasal obstruction, dysphagia, and hoarseness of voice depending on the location of the tumor. The preoperative diagnosis is difficult. Although preoperative imaging or fine needle aspiration cytology may help to reveal diagnosis, they are inadequate. The definitive diagnosis is made by histopathological examinations.

Inter-capsular resection of cervical vagus nerve schwannoma

Cervical vagus nerve schwannoma is rare and its surgical procedure is controversial. The tumor is in general benign and slowly growing without causing symptoms, and therefore it should be advised to remove the tumor while preserving neural function. We operated on two patients with cervical vagus nerve schwannoma with the inter-capsular resection technique proposed by Hashimoto et al. without causing neurological deficits. It is the first time that the plane between the tumor-complex capsule layer (epineurium and perineurium) and true tumor capsule layer was histopathologically proved in this paper. The true tumor capsule layer contained no normal neural fibers, tumor tissues and neural sheath. The inter-capsular resection technique is a safe and reliable method for removing cervical vagus nerve schwannoma.

Large Cervical Vagus Nerve Tumor in a Patient with Neurofibromatosis Type 1 Treated with Gross Total Resection: Case Report and Review of the Literature

Neurofibromas are benign peripheral nerve sheath tumors that occur commonly in individuals with neurocutaneous disorders such as neurofibromatosis type 1. Vagal nerve neurofibromas, however, are a relatively rare occurrence. We present the case of a 22-year-old man with neurofibromatosis type 1 with a neurofibroma of the left cervical vagal nerve. The mass was resected through an anterior approach without major event. In the postoperative course, the patient developed left vocal cord paralysis treated with medialization with injectable gel. We then present a comprehensive review of the literature for surgical resection of vagal nerve neurofibromas.

Diagnosis and management of schwannomas originating from the cervical vagus nerve

INTRODUCTION

A schwannoma is a benign, slow growing, encapsulated nerve sheath tumour. Presentation of a schwannoma is a diagnostic and management challenge.

METHODS

Internet searches of PubMed/MEDLINE(®) for all articles listing schwannomas of the vagus nerve in the cervical/neck region (1980-2012) were undertaken to ascertain diagnostic pitfalls. The references of all articles were cross-checked to include all pertinent contributions. Further articles were traced through reference lists.

RESULTS

Schwannomas are solitary, well circumscribed and medial to the carotid sheath. Preoperative diagnoses of schwannomas in the lateral part of the neck can cause confusion with its nerve of origin (ie whether it arises from the vagus nerve or a sympathetic chain). Computed tomography and magnetic resonance imaging reveal valuable information regarding the location and origin of the tumour as well as aiding surgical planning. The diagnosis can be confirmed intraoperatively. Postoperative recovery of neurological function is dependent on the type of surgery. Histopathological studies searching for classical features and immunohistochemical staining for S100 also confirm the diagnosis.

CONCLUSIONS

Schwannomas should be considered in the differential diagnoses of unusual masses in the neck. Preoperative imaging elicits valuable information regarding the location and origin of schwannomas and histopathology confirms the diagnosis.

[Cervical vagus nerve schwannoma: diagnostic and therapeutic strategies]

Les schwannomes cervicaux sont des tumeurs bénignes des nerfs périphériques développées exclusivement à partir des cellules de Schwann. L'atteinte du nerf vague cervical est relativement rare, et les auteurs en rappellent, à partir d'un cas, les signes radiologiques évocateurs ainsi que les caractéristiques histologiques. Le traitement de ces tumeurs est chirurgical. Un patient de 32 ans consultait pour une masse latéro-cervicale supérieure droite isolée, évoluant depuis trois ans. Une imagerie médicale (TDM et IRM) cervicale mettait en évidence une masse vascularisée au temps retardé, refoulant la veine jugulaire interne en dehors et l'axe carotidien en dedans. Un examen cytologique non contributif conduisait à réaliser une exérèse chirurgicale extracapsulaire de la masse par voie de cervicotomie. Il s'agissait d'une tumeur rétro-jugulo-carotidienne développée aux dépens du nerf vague cervical droit. L'analyse histologique concluait à un schwannome. Les suites opératoires étaient simples. Le schwannome du nerf vague est une tumeur bénigne rare, qui doit être évoquée devant toute masse latérocervicale isolée. L'imagerie médicale (TDM et IRM) cervicale préopératoire représente les examens de choix indispensable pour évoquer le diagnostic. Le traitement est chirurgical, afin de confirmer le diagnostic histologique. L'exérèse chirurgical complète extracapsulaire est possible et est le seul garant de la non récidive.

Extra vestibular schwannoma: a two year experience

We present series of head, neck extracranial non-vestibular schwannomas treated during 2-year period. All patients with head and neck schwannomas treated at our department from April 2007 to July 2009 were reviewed. There was female predominance (72%). The mean age at diagnosis was 38 years. All (100%) presented with a neck mass. Most common nerves of origin were the vagus and the cervical sympathetic chain. Treatment for all cases was complete excision with nerve preservation. Among all schwannoma patients, postoperative neural deficit occurred in four with partial to complete resolution in three. The follow-up period was 24 months. 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.

Schwannoma in head and neck: preoperative imaging study and intracapsular enucleation for functional nerve preservation

PURPOSE

In treating schwannoma patients, it is critical to determine the origin of the tumor to preserve nerve function. We evaluated the validity of preoperative imaging studies in distinguishing the neurological origin of the schwannomas of the head and neck, and the efficacy of intracapsular enucleation in preserving nerve function.

MATERIALS AND METHODS

In 7 cases of schwannomas in the head and neck region, we predicted whether the tumor originated from the vagus nerve or the cervical sympathetic chain through imaging studies including computed tomography (CT) and magnetic resonance imaging (MRI). All patients were performed intracapsular enucleation, and the function of the vagus nerve and the sympathetic nerve was evaluated preoperatively and postoperatively.

RESULTS

Preoperative imaging studies showed 6 cases where the tumor was located between the carotid artery and the internal jugular vein, and 1 case where the tumor was located posteriorly, displacing the carotid artery and the internal jugular vein anteriorly. At the time of operation, we confirmed schwannoma originating from the vagus nerve on the first 6 cases, and schwannoma originating from the sympathetic nervous system on the last case. All patients went through successful intracapsular enucleation, and of the seven schwannoma cases, 6 patients maintained normal postoperative neurological function (85.7%).

CONCLUSION

Preoperative imaging studies offer valuable information regarding the location and origination of the tumor, and intracapsular enucleation helped us to preserve the nerve function.

Alternative Surgical Approaches for Apical Neurinomas: A Thoracoscopic Approach

BACKGROUND

Neural tumors at the thoracic apex present technical problems for surgeons because of their inaccessibility and postoperative neural complications. Although several approaches offering better accessibility have been proposed, none have become standard.

METHODS

Between 1976 and 2004, 23 patients, histologically 20 neurilemmomas and three ganglioneuromas, underwent surgical intervention for apical neurinoma. Surgical approaches were in three groups: (1) open thoracotomy, 8 patients; (2) transcervical, 10 patients; and (3) video-assisted thoracoscopy utilizing intracapsular enucleation to preserve important nerves and vessels, 5 patients. Perioperative variables and postoperative neurological complications were reviewed and compared among the groups.

RESULTS

Operation time and t blood loss in the vessels group were significantly less than in the other groups. Multivariate analysis with the perioperative variables showed the transcervical approach to be an independent predictor for postoperative neurologic complications (p = 0.0029). All patients remain free from recurrence, even in the follow-up period for patients in the vessels group ranging from 6 to 60 months (average, 35 months).

CONCLUSIONS

Video-assisted thoracoscopic intracapsular enucleation, when an apical neurinoma is benign and well-capsulated, is the optimal treatment to preserve nerve function. Careful follow-up to monitor for recurrence is necessary.

Unusual cases of cervical nerves schwannomas: phrenic and vagus nerve involvement

Benign neurogenic tumors (neurilemmoma) arising from the cervical phrenic or vagus nerve are relatively rare. These lesions are benign, asymptomatic and incidentally found. We describe two cases considering different surgical techniques adopted. In the case of phrenic nerve schwannoma we performed a total excision of the tumor including the maternal nerve fiber to prevent tumor recurrence, also in regard to the already present hemidiaphragm palsy. On the other hand in second case, in which the vagus nerve was involved, we proposed a microsurgical approach by monitoring nerve function in order to minimize nerve damage.