Intrathoracic vagal nerve schwannoma preoperative diagnosis is correct because of clinical and characteristic ct findings —A case report and review of the literature—

A 60-year-old man was operated with the clinical diagnosis of intrathoracic vagal nerve schwannoma because of characteristic CT findings and no symptom of neurofibromatosis. Thoracoscopic surgery was performed and it was confirmed pathologically. Intrathoracic vagal nerve tumor is rare, so preoperative diagnosis seems to be difficult. We review the intrathoracic vagal nerve tumors reported in Japan (52 cases of schwannoma and 9 cases of neurofibroma), and analyzed the tumor location, furthermore, the relationship of neurofibromatosis and schwannoma and neurofibroma on vagal nerve tumor.     

A case of mediastinal schwannoma originating from the intrathoracic vagal nerve

A 46-years-old man was admitted because of an abnormal shadow on X-ray. The operation underwent under the diagnosis of benign tumor in the antero-superior mediastinum. At the operation, the tumor arise from the right intrathoracic vagal nerve and it was resected with the transection of vagal nerve. The histological diagnosis was schwannoma. Postoperative course was uneventful except the slight hoarseness. Intrathoracic vagal tumor is rare and we have found 19 reported cases among Japanese literatures. This case is considered to be the 20th case originated from the intrathoracic vagal nerve in Japan.     

Bilateral cervicomediastinal neurofibroma originating from the vagal nerve in a patient with von Recklinghausen's disease: report of a case

A 19-year-old woman with von Recklinghausen's disease was admitted with symptoms of hoarseness. A computed tomography scan showed a bilateral cervicomediastinal tumor. An extirpation of the left cervicomediastinal tumor was performed for the purpose of diagnosis and treatment. On thoracotomy, the tumor, which measured 9 × 8 × 4 cm in size, arose from the intrathoracic vagal nerve and the left tumor was resected with a segment of the vagal nerve and recurrent nerve. The pathological diagnosis of the tumor was a neurofibroma. The tumor on the right side was left untreated due to concerns about possibly causing palsy of the bilateral recurrent nerve and also because of the asymptomatic state of the right tumor. Mediastinal neuofibroma in a patient with von Recklinghausen's disease often arises from the intrathoracic vagal nerve. To our knowledge, this is the first report of bilateral cervicomediastinal neurofibroma originating from the vagal nerves. Received: November 15, 2001 / Accepted: May 7, 2002 Reprint requests to: M. Ohta     

A case of mediastinal vagal nerve neurinoma: a familial neurinomatosis]

We experienced an operation of a 16-year-old female of mediastinal vagal neurinoma. Abnormal shadow was pointed out on chest X-ray at physical examination of high school. Right thoracotomy was performed under the diagnosis of mediastinal tumor. There was a walnut sized mass on the right vagal nerve at just peripheral side of the recurrent nerve branch. The vagal nerve was cut at both sides of the mass not to injure the recurrent nerve. The tumor was removed en block. Two little finger sized masses were recognized in serratus anterior muscle and 5 th. intercostal nerve. These removed masses were diagnosed as neurinoma pathologically. While the mother of this case had been admitted on another hospital because of multiple neurinomatosis with bilateral acoustic neurinoma. Thus this case is of familial neurinomatosis, suggesting it's heredity like as neurofibromatosis (von Recklinghausen's disease).     

Esophageal schwannoma

A rare case of esophageal schwannoma is presented. A 63-year-old woman was admitted to our hospital with a 5-year history of dysphagia. The barium esophagogram showed a protrusive smooth tumor in the upper thoracic esophagus. The tumor was removed through right thoracotomy. There was no anatomical relationship between the tumor and vagal nerve trunk. From pathologic findings and positive immunohistochemical staining for S-100 protein, the diagnosis of esophageal schwannoma was made.     

An operative case of benign schwannoma originating in the intrathoracic vagal nerve

A 50-years-old man was admitted with cough and abnormal shadow on the chest film. The tumor originated from the left vagal nerve in the antero-superior mediastinum. Subcapsular extirpation was performed to save the nerve function, since the tumor located in the site proximal to the branching point of the recurrence nerve. Pathological diagnosis was a benign schwannoma. Though H-E and Bodian stain did not show any nerve fibers in the schwannoma, postoperative hoarseness arose. In this country, 4 cases of subcapsular extirpation have been performed, but all of them had postoperative hoarseness. We think that postoperative hoarseness cannot be prevented by the subcapsular extirpation.     

Vagal paraganglioma. Report of a case surgically treated and review of the literature

The authors report the observation of one case of vagal paraganglioma occurred in a young woman. The tumor manifested itself as a left sub-mandibular tumescence; the very first diagnostic approach was achieved through echography, which showed a mass behind the internal carotid artery and compressing the internal jugular vein. The following examinations, represented by neck CT, NMR, angiography and fine needle aspiration initially directed towards the suspicion of chemodectoma. Only at operation, the anatomical situation of the tumor, which encapsulated the vagus nerve and the subsequent results of the hystological examination revealed the correct diagnosis of vagal paraganglioma.     

Cervicothoracic vagal neurilemoma: Report of a case

We report herein the rare case of a 45-year-old man with a cervicomediastinal neurilemoma of the vagus nerve. The tumor was 160×40×35 mm in size and extended from the angle of the right mandible to the aortic arch. Despite this being the largest such tumor ever reported, the patient presented without any symptoms. Thus, although vagal neurilemoma is uncommon, it should nevertheless be included in the differential diagnosis of any asymptomatic mass along the vagus nerve. In the evaluation of such masses, magnetic resonance imaging can provide useful information regarding not only the location, but also the nature of the lesion.     

Neurofibroma originated from the intrathoracic vagal nerve in a patient with von Recklinghausen's disease--a case report

A neurofibroma originated from the intrathoracic vagal nerve was presented. A 26-year-old male was found to have an abnormal shadow in the right chest filed on a routine examination. He was complicated with Von Recklinghausen's disease and showed multiple "cafe au lait" spots over his extremities and trunk but no subcutaneous mass. A block resection of the mass was carried for the mediastinal tumor. The tumor was arising from the right intrathoracic vagal nerve which located just below the origin of recurrent nerve and was measured 3 X 3 X 6 cm. Histological examination of the specimen revealed neurofibroma. His postoperative course was uneventful. A brief review in Japan was made on 22 cases collected from the literature.     

Multiple schwannoma of the intrathoracic vagal nerve; report of a case

A 67-year-old male referred to our hospital for the close examination of abnormal chest X-ray findings. Chest X-ray films showed abnormal shadows in the right lung field. Chest computed tomography (CT) scan and magnetic resonance imaging (MRI) revealed the 3 tumors which located in superior, middle and posterior mediastinum. The operation underwent under the diagnosis of neurogenic tumors originating from the right intrathoracic vagal nerve. At the operation, the tumors existed the vagal nerve distal to the recurrent laryngeal nerve and they were resected with the transection of vagal nerve. The masses were histologically diagnosed as schwannoma. We reported a rare case of multiple schwannoma arising from the intrathoracic vagal nerve. He had no postoperative complications, and he has been free from recurrence for 4 years postoperatively.     

Cervical paragangliomas-tumor control and long-term functional results after surgery.

Objective: To report long-term functional results of the surgical treatment of cervical paragangliomas. Patients and Methods: A retrospective review of 22 patients with 34 head and neck paragangliomas of which 27 were resected between 1981 and 2004. Of these, 16 were carotid body tumors and 11 were vagal paragangliomas. There were 13 women and 9 men with an average age of 48.6 years (range, 26 to 75 years; median, 49 years) and the mean follow-up period was 82 months (range, 3 to 184 months; median, 61 months). Results: There were 13 solitary tumors of which 5 were carotid body tumors and 8 vagal paragangliomas. Multiple head and neck paragangliomas were seen in 9 patients (41%). The incidence of associated multiple tumors was 64.3% for carotid body tumors and 38.5% for vagal paragangliomas. Complete tumor resection was achieved in all but 1 patient in whom a small intradural residual vagal paraganglioma had to be left. The internal carotid artery was preserved in all carotid body tumor resections. Lower cranial nerve deficits were sustained in 1 carotid body tumor resection only, but in all cases with multiple tumors. All patients with vagal paragangliomas had or developed a vagal nerve paralysis. In 4 cases minor complications developed postoperatively. No recurrent tumors were seen during the follow-up period. Conclusions: Even in large head and neck paragangliomas surgical treatment provides excellent tumor control with low postoperative morbidity. A wait-and-scan policy may be more appropriate for those patients with multiple tumors, advanced age, or high operative risk and for those whose tumors have recurred following radiotherapy.     

A case of mediastinal schwannoma originating from the thoracic vagal nerve complicated by early stomach cancer

Most of primary tumors of the nerves arising in the mediastinum originate from the sympathetic or intercostal nerves. Schwannoma developing from the vagal nerve is very rare. The patient was a 73-year-old male referred to us with abnormal chest X-rays and stomach cancer. One-staged operation was performed by thoracic and upper abdominal median incision. The tumor was removed, which measured 6 X 5 X 4 cm and involved the origin of the left recurrent nerve, by neurectomy. To our knowledge, this was the 18th reported case of schwannoma of the intrathoracic vagal nerve in Japan. A similar schwannoma was observed also in the celiac plexus, and this case was also a rare instance of multiple schwannoma.     

Vagal body tumors

Six cases of vagal body tumor are reviewed. All first presented as painless neck masses with normal cranial nerve function. Otologic symptoms were infrequent, occurring only with temporal bone involvement. In true vagal paragangliomas, cranial nerve and auditory function is usually preserved until there is extensive disease of the skull base. Tumor progression after radiotherapy was documented in four patients, three of whom were treated with 4500 cGy or more. One patient was found to have regional lymph node metastases. The six patients had a total of 10 head and neck paragangliomas, illustrating the high incidence of synchronous and metachronous lesions. Because of the high incidence of multiple lesions, these tumors threaten lower cranial nerves bilaterally in many instances. Because cranial nerve function is preserved until late, and because vagal and accessory nerve paralysis is usually unavoidable with resection, we advocate conservative treatment in selected cases. It may be reasonable to postpone surgery until cranial nerve impairment becomes evident or other vital structures are threatened.     

Recovery of audition after favorable resection of vagal schwannoma

Two patients with vagal schwannoma manifesting as deafness with no lower cranial nerve paresis were treated surgically. A 42-year-old male underwent partial resection of the tumor, which was tightly adhered to the cranial nerves, to prevent lower cranial nerve paresis. A 29-year-old female underwent total removal of the tumor without complications. The patients recovered useful audition with no postoperative deficit.     

Identification of the non-recurrent inferior laryngeal nerve using intraoperative neurostimulation

INTRODUCTION: The non-recurrent inferior laryngeal nerve occurs at a frequency of about 0.5% and usually on the right side. The identification of a non-recurrent laryngeal nerve may be difficult. We describe a new method for its identification using intraoperative neurostimulation. METHODS: We examined nine patients with a non-recurrent inferior laryngeal nerve and five patients with a normal inferior laryngeal nerve anatomy who were operated on trans-sternally. Neurostimulation of the vagal nerve producing electromyographic signal in the intrinsic laryngeal musculature was performed at different points proximally and distally. RESULTS:: Electromyographic signals were found proximally but not distally of the separation of the inferior laryngeal nerve from the vagus in 14 patients. In nine patients with a non-recurrent inferior laryngeal nerve, we performed neurostimulation of the vagus opposite the lower and the upper thyroid poles. In all patients we found no electromyographic signals at the distal stimulation point. In contrast, proximal neurostimulation of the vagus opposite the upper thyroid pole produced positive electromyographic signals. CONCLUSION: Neurostimulation of the vagal nerve distally of the separation of the inferior laryngeal nerve did not produce electromyographic signals in the intrinsic laryngeal musculature, perhaps due to the different modalities in the vagal fascicles. Negative electromyographic signals following neurostimulation of the distal vagal nerve opposite the lower thyroid pole should lead to proximal neurostimulation of the vagus opposite the upper thyroid pole. Positive electromyographic signals proximally and negative electromyographic signals distally predict the occurrence of a non-recurrent inferior laryngeal nerve which allows its diagnosis before surgical dissection of the thyroid gland and may prevent nerve palsy.     

Continuous Positive Airway Pressure Increases Vagal and Phrenic Nerve Activity in Cats

To investigate how continuous positive airway pressure (CPAP) changes the vagal nerve activity and whether CPAP alters the efferent phrenic nerve activity or the breathing pattern similarly before and after vagotomy, a study was made of vagal and phrenic nerve activity in chloralose-anaesthetized cats. In the vagal nerve, CPAP increased the mean impulse frequency during expiratory rest. The breath-related impulse frequency also increased with CPAP. With higher CPAP (greater than or equal to 0.5 kPa), the peak of breath-induced activity in the vagal nerve lasted longer than inspiration. In the phrenic nerve, the impulse frequency in the bursts increased almost linearly with CPAP irrespective of whether the vagal nerves were intact or not. The duration of the phrenic nerve bursts decreased with increasing CPAP when the vagal nerves were intact. When the vagal nerves were cut, the burst duration did not change. The rate of breathing was almost unchanged by CPAP regardless of whether the vagal nerves were cut or not. The inspiration/expiration ratio decreased with increasing CPAP when the vagal nerves were intact, but not when they were cut.     

Vagal Nerve Monitoring during Parapharyngeal Space Tumor Removal

The vagus nerve innervates the intrinsic and extrinsic laryngeal musculature as well as the complex pharyngeal plexus. Acute paralysis of this nerve results in dysfunctional speech, deglutition, and airway protection. These untoward effects, which lead to additional infectious and aerodigestive complications, may arise following manipulation of the vagus nerve during the surgical removal of a variety of neoplasms found in the parapharyngeal space.The vagal nerve has been intraoperatively monitored in an effort to maintain its anatomic and functional integrity. Bipolar hook-wire electrodes are introduced transcutaneously through the cricothyroid membrane and are guided into the vocalis muscle by an assistant performing direct laryngoscopy. Continuous, real-time monitoring of the vagal nerve is provided by audio and visual feedback to the operating surgeon. Potentially injurious stretching, heating, and compression of the nerve are easily detected, and monopolar stimulation of the nerve is used to map the nerve's course through the tumor bed.This presentation outlines our technique for vagal nerve monitoring in patients with tumors of the parapharyngeal space and intact preoperative vocal cord mobility. Selected cases are presented and illustrated through intraoperative and postoperative videotapes.     

Cervical sympathetic schwannoma: case report

OBJECTIVE AND IMPORTANCE: Approximately 20 to 27% of neck masses in the parapharyngeal space may be benign nerve sheath tumors. Cervical sympathetic chain schwannomas or vagal nerve schwannomas are most common. We report a patient with a cervical sympathetic chain schwannoma. CLINICAL PRESENTATION: The patient was a 47-year-old Caucasian man with a 7-month history of a painless, enlarging right neck mass. No hoarseness or Horner's syndrome was found preoperatively. Formal head and neck examination in the otolaryngology department revealed no vocal cord dysfunction. INTERVENTION: By use of a standard right carotid incision, a tumor was identified growing from the cervical sympathetic chain posterior to the carotid bifurcation. A gross total resection was performed and a section of the cervical sympathetic chain was sacrificed. CONCLUSION: Cervical sympathetic chain schwannomas are unusual tumors that require microneurosurgical resection for cure. We discuss the differential diagnosis, evaluation, surgical management, and pathological characteristics of such tumors and review the literature.     

Vagal Nerve Monitoring during Parapharyngeal Space Tumor Removal

The vagus nerve innervates the intrinsic and extrinsic laryngeal musculature as well as the complex pharyngeal plexus. Acute paralysis of this nerve results in dysfunctional speech, deglutition, and airway protection. These untoward effects, which lead to additional infectious and aerodigestive complications, may arise following manipulation of the vagus nerve during the surgical removal of a variety of neoplasms found in the parapharyngeal space.

The vagal nerve has been intraoperatively monitored in an effort to maintain its anatomic and functional integrity. Bipolar hook-wire electrodes are introduced transcutaneously through the cricothyroid membrane and are guided into the vocalis muscle by an assistant performing direct laryngoscopy. Continuous, real-time monitoring of the vagal nerve is provided by audio and visual feedback to the operating surgeon. Potentially injurious stretching, heating, and compression of the nerve are easily detected, and monopolar stimulation of the nerve is used to map the nerve's course through the tumor bed.

This presentation outlines our technique for vagal nerve monitoring in patients with tumors of the parapharyngeal space and intact preoperative vocal cord mobility. Selected cases are presented and illustrated through intraoperative and postoperative videotapes.

     

Phrenic and Vagal Nerve Activities during Spontaneous Respiration and Positive-Pressure Ventilation

Afferent vagal nerve activity from stretch-receptors in the lung and efferent phrenic nerve activity were recorded during spontaneous respiration and during positive-pressure ventilation with three different types of ventilators. During spontaneous respiration the efferent phrenic nerve activity slightly preceded the afferent vagal nerve activity. Volume-controlled ventilation did not alter the phrenic nerve activity when the ventilation was set at a rate equal to that during spontaneous respiration, but afferent vagal volleys increased in duration. At higher frequencies of insufflation spontaneous inspiration was inhibited.
An increase in afferent vagal nerve activity and a concomitant slight decrease in efferent phrenic nerve activity were obtained during animal triggered pressure-controlled ventilation.
High-frequency positive-pressure ventilation (HFPPV) gave rise to basal, non-grouped activity in vagal afferents, causing inhibition of inspiration. During HFPPV, spontaneous respiration can take place on activation of other afferents to the respiratory centre.
Clinical aspects of respirator treatment from a neurophysiological standpoint are discussed.