Schwannoma of the vagus nerve, a rare middle mediastinal neurogenic tumor: case report

Schwannoma originating from the vagus nerve within the mediastinum is a rare, usually benign tumor. A 44-year old male was presented with chest pain. Chest radiography, CT scan and MRI showed a well circumscribed mass, 5 × 4 cm located in the aortopulmonary window. The mass was found at surgery to be in close proximity with the aortic arch and the left pulmonary hilum, alongside the left vagus nerve. The encapsulated tumor was completely resected through a left thoracotomy incision and it was found to be a benign schwannoma in pathology. The patient is free of recurrence 6 years after surgery.     

Cervico-mediastinal schwannoma of the vagus nerve: resection with intraoperative nerve monitoring

Schwannomas are usually benign, single, encapsulated, slow-growing tumours originating from cranial or spinal nerve sheaths. The vagus nerve involvement at the mediastinal inlet is very uncommon. For anatomical reasons, the resection of cervical and mediastinal schwannoma of the vagus nerve has a high risk of vocal fold paralysis. We describe the case of a 67-year-old female with a cervico-mediastinal schwannoma of the vagus nerve that we removed using the intraoperative neuromonitoring technique. The patient presented with mild hoarseness and complained of discomfort behind the jugular notch. Neck and chest computerized tomography described a 35 × 30 mm solid lesion behind the left clavi-sternal junction; preoperative fine needle aspiration cytology revealed schwannoma. Resection of the mass was performed with a cervical approach and the vagus nerve tumour was completely removed under continuous neuromonitoring (NIM-3^® System), preserving the vagus and the recurrent laryngeal nerve function. Pathology on the resected mass documented A-type schwannoma with “ancient schwannoma” areas. The intraoperative neurostimulation and neuromonitoring approach for the resection of vagus schwannoma are recommended because it may reduce the risk of injury to the vagus and to the recurrent laryngeal nerve.     

Neurilemmoma of the posterior tibial nerve with an uncommon case presentation.

A neurilemoma presenting in the foot is uncommon. The tumor is a solitary benign type that does not require transection of the involved nerve. A clinical review with an uncommon presentation and brief history of a benign neurilemoma is presented, followed by a discussion using magnetic resonance imaging, ultrasonification, double contrast doppler, arteriograms and venograms to aid in a differential diagnosis.     

A posterior tibial nerve neurilemoma unrecognized for 10 years: case report

OBJECTIVE AND IMPORTANCE: Neoplasms of peripheral nerves can be obscured, especially during the early phase. The author reports a patient with a posterior tibial nerve neurilemoma (schwannoma). For a decade, the tumor was misdiagnosed as nonspecific S1 radiculopathy and psychogenic chronic pain syndrome. The patient's presentation and initial management are unique. CLINICAL PRESENTATION: A 40-year-old woman reported severe left foot and calf pain, numbness, and weakness. The symptoms were evident during three pregnancies, and they gradually progressed. The neuropathic pain was protracted, despite implantation of a dorsal column stimulator and administration of a wide variety of medications and therapies. The symptoms were unresponsive to both inpatient and outpatient treatments, which resulted in a misdiagnosis of psychogenic pain for more than a decade. Diagnostic scans obtained by computed tomography, ultrasonography, and nuclear scintigraphy confirmed a popliteal fossa mass. INTERVENTION: A high, large posterior tibial nerve neurilemoma was found intraoperatively, positioned just below the sciatic nerve bifurcation with extensive degenerative features and hemorrhages. Surgical resection provided immediate recovery. CONCLUSION: Peripheral nerve tumors are rarely acknowledged clinical entities. Chronic unexplained foot and calf pain and a positive Tinel's sign should raise suspicion of posterior tibial nerve neurilemoma. Even in patients who have had such tumors for a decade, surgical resection remains the treatment of choice.     

Tarsal Tunnel Syndrome Secondary to Schwannoma of the Posterior Tibial Nerve

Schwannoma is a benign tumor that arises from the peripheral nerve sheath. It presents as a discrete, often tender, and palpable nodule associated with neurogenic pain or paresthesia when compressed or traumatized. The growth rate is usually slow, and these lesions seldom exceed 2 cm in diameter. We report the case of a large schwannoma arising from the posterior tibial nerve located in the posterior medial ankle. The core needle biopsy findings were suggestive of a schwannoma, with spindle cells strongly and uniformly immunostaining for S-100 protein. The mass was marginally excised. The surgical specimen consisted of a grossly encapsulated white-yellow mass with irregular contours, measuring 3.7 × 3.5 × 2.7 cm. The cut surface showed areas of pin-point hemorrhage. The patient did not encounter any motor deficits; however, early results showed some subjective numbness. Few reports have been published of schwannomas arising from the tibial nerve. Marginal excision appears to be the recommended therapy for this tumor, without any evidence of recurrence at 9 months of follow-up.     

Intraoperative Vagus Nerve Monitoring: A Transnasal Technique during Skull Base Surgery

Objectives Intraoperative vagus nerve monitoring during skull base surgery has been reported with the use of an oral nerve monitoring endotracheal tube. However, the intraoral presence of an endotracheal tube can limit exposure by its location in the operative field during transfacial approaches and by limiting superior mobilization of the mandible during transcervical approaches. We describe a transnasal vagus nerve monitoring technique. Design and Participants Ten patients underwent open skull base surgery. Surgical approaches included transcervical (five), transfacial/maxillary swing (three), and double mandibular osteotomy (two). The vagus nerve was identified, stimulated, and monitored in all cases. Main Outcome Measures Intraoperative nerve stimulation, pre- and postoperative vagus nerve function through the use of flexible laryngoscopy in conjunction with assessment of subjective symptoms of hoarseness, voice change, and swallowing difficulty. Results Three patients had extensive involvement of the nerve by tumor with complete postoperative nerve deficit, one patient had a transient deficit following dissection of tumor off of nerve with resolution, and the remaining patients had nerve preservation. One patient experienced minor epistaxis during monitor tube placement that was managed conservatively. Conclusions Transnasal vagal nerve monitoring is a simple method that allows for intraoperative monitoring during nerve preservation surgery without limiting surgical exposure.     

Neurilemoma of the popliteal fossa: report of two cases with long subclinical course and misleading presentation

The authors report two cases of neurilemoma localised in the popliteal fossa. Both patients experienced non-specific symptoms, such as painful numbness and burning dysaesthesia, involving the lower extremity. Tinel's sign was positive over the popliteal fossa. The patients sought medical advice and underwent conservative treatment without any relief, for a long time before the right diagnosis was made. Magnetic resonance imaging revealed in both patients a well- circumscribed mass posterior to the sciatic nerve, occupying the popliteal fossa. Following surgical excision of the neurilemoma, the patients experienced immediate relief of their chronic symptoms. In similar situations, ultrasound or magnetic resonance imaging of the whole sciatic nerve should be performed if this is indicated by detailed physical examination. Once the diagnosis is made, neurilemomas should be surgically removed, in order to exclude malignancy, prevent neurologic deficits and provide relief of symptoms.     

Assisted thoracoscopic resection of huge mediastinal neurogenic tumor with Horner syndrome and superior vena cava syndrome

A 51-year-old female suffering from right shoulder pain had chest radiography, which showed the huge round shadow (10 x 8.5 x 8.0 cm) on the right upper lung field. Horner syndrome and superior vena cava syndrome were presented. Thoracoscopic appearance showed that the tumor with complete smooth capsulation was neurogenic. After that added ideal thoracotomy (compatible with location and length) was performed, from which tumor was carried out and made a pathologic diagnosis of neurilemoma originated from thoracic sympathetic nerve. Harmonic Scalpel, an ultrasonically activated surgical device was effective in such a case of using near by nerve and small vessels. After operation, superior vena cava syndrome except for Horner syndrome was improved. It is important that we should consider less invasive and safe approach with combination of thoracoscopic and thoracotomic procedures even in case of huge tumor.     

Intrathoracic tumors arising from the vagus nerve. Review of resected tumors in Japan

Nineteen surgically treated intrathoracic vagus nerve tumors (16 neurilemmomas, 3 neurofibromas), including three treated by the authors, were reviewed. Tumor resection with vagus nerve amputation was performed in 14 and intracapsular excision without nerve amputation in 3 of the 17 adequately recorded cases. The location of vagus nerve tumor was the left upper mediastinum in 11 patients, almost all of whom were hoarse postoperatively due to sacrifice of the recurrent laryngeal nerve.     

Radial nerve paralysis and tumor

This paper presents ten cases of radial nerve paralysis because of tumor and reviews 38 previously reported cases. The tumor distribution was 35 lipomas, four neurofibromas, four ganglions, three neuromas, one fibroma, and one neurilemoma. Malignant tumors are not discussed in this review. Electromyography is of value if diagnostic problems occur. Postoperative results are normally good.     

Neurilemoma of the medial plantar nerve: a case report.

The incidence of neurilemoma in the foot is uncommon. Neurilemoma of the medial plantar nerve distal to the tarsal tunnel, with symptoms isolated to the foot, is rare. A case presentation of neurilemoma arising from the distal portion of the medial plantar nerve that was identified and excised is presented with a 19-month follow-up.     

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     

Effects of vagal cryo-interruption on colon contractions in monkeys

The influence of the vagus nerve on normal colon contractions, and the distal extent of this influence along the colon, is unknown. It is generally thought that the vagus nerve has little, if any, influence on normal colon contractions, and if there is any effect, it is limited to the proximal colon. The technique of reversible truncal vagotomy by cooling (vagal cryo-interruption) was used to explore the influence, and extent of any influence, of the vagus nerve on contractions of the colon in unanesthetized monkeys. Each monkey was subjected to vagal cryo-interruption in the fasted and fed states. In both states this caused a significant decrease in contractions in the proximal, middle, and distal portions of the colon, compared with baseline control and recovery periods. These studies indicate that the vagus nerve plays a role in normal contractions of the intra-abdominal colon in both the fasted and the fed states and that it also plays a role in the gastrocolic response.     

Right nonrecurrent laryngeal nerve deforming a superior parathyroid adenoma: report of a case

A 34-year-old patient with primary hyperparathyroidism and repeated renal stones underwent a parathyroidectomy. During operation, a right superior parathyroid adenoma was found which measured 3.5 × 1.5 × 1.0 cm in size. The right nonrecurrent laryngeal nerve passed over the middle of the adenoma, and deformed the parathyroid into a dumbbell shape. Magnetic resonance angiography revealed an absence of the right innominate artery and an independent origin of the right retroesophageal subclavian and common carotid artery. The combination of the parathyroid tumor and nonrecurrent laryngeal nerve is extremely rare, especially in Asia. To avoid surgical complications, it is important to understand the possibility of a nonrecurrent laryngeal nerve developing in such patients. Received: July 9, 2001 / Accepted: November 20, 2001     

Primary neurilemoma of the thyroid gland: Report of a case

Neurilemoma, like other non-epithelial tumors, seldom occurs in the thyroid gland. A 57-year-old man was first referred to our hospital with an asymptomatic anterior neck tumor. A solid tumor was detected in the right lobe of the thyroid and an enucleation of the thyroid tumor was performed. The tumor was 35×33×33 mm in size, and diagnosed as Antoni A type neurilemoma. We were only able to find seven previously reported detailed cases of primary neurilemoma of the thyroid gland. A review of these cases, however, revealed that neurilemoma tends to develop in the right lobe of the thyroid gland. An operation is thus considered necessary and an enucleation of the tumor is appropriate.     

Mediastinal granular cell tumor: report of a case

Mediastinal granular cell tumor is rare. We report a case of 16-year-old woman with a granular cell tumor in the right upper-middle mediastinum. Chest computed tomography (CT) and magnetic resonance imaging (MRI) revealed a 4.0 x 2.5 x 5.5 cm well circumscribed mass in the right upper-middle mediastinum. Tumor resection was performed. It was found that the tumor involved right vagus nerve. The tumor was completely excised with combined resection of the right vagus nerve peripheral to the right recurrent nerve. Histopathologically, the tumor consisted of round to polygonal cells with abundant eosinophilic granular cytoplasm, and diagnosed a granular cell tumor.     

Pancreatic schwannoma: A rare case and a brief literature review

IntroductionPancreatic schwannoma (PS) is an extremly rare benign tumor. Less than 50 cases of pancreatic schwannoma have been described in the English literature over the past thirty years.Presentation of case reportA 63-year-old female underwent left modified radical mastectomy 2 years ago due to breast cancer. During her routine check-up, a 65 × 63 × 55 mm measured calcified, well-demarcated, cystic-mass having septations and calcifications that localized to the pancreatic head was detected by abdominal computerized tomography. She was asymptomatic and her tumor markers were in normal ranges. A standard Whipple procedure was performed, and the histo-pathological diagnosis of the resected specimen was reported as ancient schwannoma with clear surgical margins. Patient’s postoperative course was eventful. She had a biliary leakage after surgery which was managed conservatively. She is under follow-up.DiscussionPancreatic schwannoma also known as neurilemoma or neuroma is a slowly growing, encapsulated, mostly benign tumor with smooth well-delineated margins that originates from myelin producing schwann cells located on the nerve sheath of the peripheral epineurium of either the sympathetic or parasympathetic autonomic fibers. PS’s are extremly rare. The head of pancreas being involved in the vast majority of cases (40%), followed by its body (20%). Management of pancreatic schwannomas remains largely controversial. Both enucleation and radical surgical resections have revealed great therapeutic efficiency. with a well prognosis without recurrences.ConclusionAlthough rare, PS’s should be considered in the differential diagnosis of the other solid or cystic masses of the pancreas.     

An intrathoracic vagus nerve schwannoma invading the trachea

A patient with a schwannoma of the intrathoracic vagus nerve is presented. The tumor invaded the trachea and caused dyspnea. It was successfully excised by a segmental resection of the trachea with end-to-end anastomosis. This instance of an intrathoracic vagus tumor invading the trachea is, as far as we know, the first reported in the world.     

Intrathoracic ganglioneuroma in an elderly patient over 70 years of age

We herein present an exceedingly rare case of intrathoracic ganglioneuroma that was surgically resected in an elderly patient over 70 years of age. A 74-year-old woman was asymptomatic, but a computed tomography (CT) scan of the thorax indicated the presence of a posterior mediastinal mass paravertebrally. A thoracotomy was thus performed under a strongly suggested diagnosis of a neurogenic tumor because of the appearance and position of the mass on the chest CT and magnetic resonance imaging findings, and measuring 6.9 × 5.8 × 1.6 cm. Not only tumors originating from the nerve sheath, but also neurogenic tumors occurring in young patients such as ganglioneuroma, should be included in the different diagnosis of posterior mediastinal tumor occurring in elderly patients.     

A case of malignant peripheral nerve sheath tumor originating from the cervical vagus nerve

A 45-year-old female presented a peripheral nerve sheath tumor (MPNST), which had progressed to malignancy from a neurofibroma arising in the left cervical vagus nerve. Neuroimaging showed that a tumor grew in the left neck area of the patient, involving the internal carotid and vertebral arteries, and invading the intracranium through the left jugular foramen. The tumor was extensively removed using a combination of the lateral suboccipital approach and the neck incision, and the frontotemporal approach accompanied with EC-IC highflow bypass and EC-MCA anastomosis. Postoperatively, pathological features demonstrated a MPNST arising from the cervical vagus nerve. Here, we discuss the clinical behavior of MPNST by quoting previous reports, and conclude by emphasizing 2 points in the treatment of MPNST; 1) that prognosis of patients with MPNST is greatly affected by the time between presenting symptoms and diagnosis, and 2) that it is very important to carefully observe neurofibroma patients, because there is a possibility of progression to malignant MPNST.