Computed tomographic features of canine intracranial and jugular foraminal masses involving the combined glossopharyngeal, vagus, and accessory nerve roots

A chronic cough, gag, or retch is a common presenting clinical complaint in dogs. Those refractory to conservative management frequently undergo further diagnostic tests to investigate the cause, including CT examination of their head, neck, and thorax for detailed morphological assessment of their respiratory and upper gastrointestinal tract. This case series describes five patients with CT characteristics consistent with an intracranial and jugular foraminal mass of the combined glossopharyngeal (IX), vagus (X), and accessory (XI) cranial nerves and secondary features consistent with their paresis. The consistent primary CT characteristics included an intracranial, extra-axial, cerebellomedullary angle, and jugular foraminal soft tissue attenuating, strongly enhancing mass (5/5). Secondary characteristics included smooth widening of the bony jugular foramen (5/5), mild hyperostosis of the petrous temporal bone (3/5), isolated severe atrophy of the ipsilateral sternocephalic, cleidocephalic, and trapezius muscles (5/5), atrophy of the ipsilateral thyroarytenoideus and cricoarytenoideus muscles of the vocal fold (5/5), and an ipsilateral "dropped" shoulder (4/5). Positional variation of the patient in CT under general anesthesia made the "dropped" shoulder of equivocal significance. The reported clinical signs and secondary CT features reflect a unilateral paresis of the combined cranial nerves (IX, X, and XI) and are consistent with jugular foramen syndrome/Vernet's syndrome reported in humans. The authors believe this condition is likely chronically underdiagnosed without CT examination, and this case series should enable earlier CT diagnosis in future cases.

Report of a vagal paraganglioma at the cervicothoracic junction

BACKGROUND

Vagus nerve paragangliomas are rare tumors, comprising 0.03% of head and neck neoplasms. These tumors are usually located cephalad to the hyoid bone, and there is only one previously reported case that arose from the lower third of the neck.

METHODS

We describe the second reported case of a lower neck vagus nerve paraganglioma that was managed with a limited sternotomy for access and surgical removal.

RESULTS

A 66-year-old male presented with a long-standing lesion of the cervicothoracic junction. CT, MRI, and Ga-68 DOTATATE PET/CT showed an avidly enhancing 5.2 × 4.2 × 11.5 cm mass extending from C6 to approximately T4 level. FNA confirmed the diagnosis. The patient underwent catheter angiography and embolization via direct puncture technique followed by excision of the mass via a combined transcervical and limited sternotomy approach.

CONCLUSION

We describe an unusual case of vagal paraganglioma at the cervicothoracic junction with retrosternal extension requiring a sternotomy for surgical excision.

Purely intracranial vagal schwannoma: A case report of a rare lesion

We present a rare intracranial vagal schwannoma along with its preoperative, intraoperative, and postoperative course.

Endocrine tumors associated with the vagus nerve

The vagus nerve (cranial nerve X) is the main nerve of the parasympathetic division of the autonomic nervous system. Vagal paragangliomas (VPGLs) are a prime example of an endocrine tumor associated with the vagus nerve. This rare, neural crest tumor constitutes the second most common site of hereditary head and neck paragangliomas (HNPGLs), most often in relation to mutations in the succinate dehydrogenase complex subunit D (SDHD) gene. The treatment paradigm for VPGL has progressively shifted from surgery to abstention or therapeutic radiation with curative-like outcomes. Parathyroid tissue and parathyroid adenoma can also be found in close association with the vagus nerve in intra or paravagal situations. Vagal parathyroid adenoma can be identified with preoperative imaging or suspected intraoperatively by experienced surgeons. Vagal parathyroid adenomas located in the neck or superior mediastinum can be removed via initial cervicotomy, while those located in the aortopulmonary window require a thoracic approach. This review particularly emphasizes the embryology, molecular genetics, and modern imaging of these tumors.

Sonographic diagnosis of a cervical vagal schwannoma

This case report illustrates the role of high-resolution sonography in the preoperative assessment of a schwannoma of the vagus nerve in the neck. Sonography identified the tumor in the right carotid space and determined its origin from the right vagus nerve, facilitating the surgeon's approach to preserve nerve function.

A rare case of vagus nerve schwannoma

Schwannomas of the vagus nerve are very rare and the differential diagnosis is extremely difficult. They are very often asymptomatic and imaging techniques are helpful, but fine needle biopsy is often inconclusive. Total resection is the treatment of choice.

Schwannoma of vagus nerve masquerading as a parotid tumour

A post-auricular swelling is the most common presentation of a parotid tumour, the majority of which are benign neoplasms like pleomorphic adenoma. This case report discusses a post-styloid parapharyngeal space tumour presenting as a post-auricular mass which, on initial clinical and cytological examination, was diagnosed as pleomorphic adenoma. A cross-sectional radiological examination revealed the true location of the mass, which was histopathologically confirmed to be a vagal schwannoma. A radiological differential diagnosis is also discussed.

Videofluoroscopic swallow studies in unilateral cricopharyngeal dysfunction

OBJECTIVES/HYPOTHESIS

Although the cricopharyngeus muscle is a ring-like structure, unilateral cricopharyngeal dysfunction can produce significant dysphagia. This entity has not been well described in the literature. The aims of the study were to identify the characteristic findings on videofluoroscopic swallow studies in patients with dysphagia secondary to unilateral cricopharyngeal dysfunction, to note the associated vagal nerve injury, and to evaluate patient outcomes following ipsilateral cricopharyngeal myotomy.

STUDY DESIGN

Retrospective clinical investigation.

METHODS

The clinic charts, electromyographic tests, videostroboscopic examinations, and videofluoroscopic swallow studies were reviewed from a series of patients who presented to our institution from 1993 to 2001 with dysphagia and findings on videofluoroscopic swallow studies suggestive of unilateral cricopharyngeal dysfunction on posterior-anterior view. In patients treated with ipsilateral cricopharyngeal myotomy, postoperative findings on swallow studies and patient outcomes were also reviewed.

RESULTS

Eighteen patients demonstrated findings characteristic of unilateral cricopharyngeal muscle dysfunction on videofluoroscopic swallow study. The common feature was a unilateral shelf-like barrier at the cricopharyngeus on the posterior-anterior view with pooling of liquid bolus in the ipsilateral pyriform sinus and episodic shunting to the contralateral side. Eight patients did not have evidence of cricopharyngeal dysfunction (ie, cricopharyngeal bar) on lateral films. Of the 18 patients, 14 had histories consistent with vagal injury secondary to trauma (n = 2), neoplastic involvement (n = 7), iatrogenic injury (n = 2), or central nervous system disease (n = 3). Results of videostroboscopic examinations demonstrated vocal fold motion impairment in 14 patients, and electromyographic test results confirmed unilateral vagal injuries in those who underwent electromyographic testing (n = 6). In the remaining 4 of 18 patients, videostroboscopic examinations demonstrated normal vocal fold abduction but impaired lengthening with a posterior glottic gap, and electromyographic test results (n = 4) indicated unilateral superior laryngeal nerve involvement. Of the 15 patients treated with ipsilateral cricopharyngeal myotomy, 1 patient required postoperative esophageal dilations for an esophageal stricture distal to the cricopharyngeus, whereas the remaining 14 patients had functional resolution of their dysphagia.

CONCLUSION

In patients presenting with dysphagia and evidence of unilateral vagal injury, careful assessment of posterior-anterior view on videofluoroscopic swallow study should be included to evaluate for unilateral cricopharyngeal dysfunction.

Using CT to localize side and level of vocal cord paralysis

OBJECTIVE

The purpose of our study was to assess the relative accuracy of imaging findings related to peripheral recurrent nerve paralysis on axial CT studies of the neck. Also assessed were imaging findings of a central vagal neuropathy.

MATERIALS AND METHODS

We retrospectively identified 40 patients who had clinically diagnosed vocal cord paralysis and had undergone CT. Eight imaging signs of vocal cord paralysis were assessed, and an imaging distinction between a central or peripheral vagal neuropathy was made by evaluating asymmetric dilatation of the oropharynx with thinning of the constrictor muscles. In two patients, we studied the use of reformatted coronal images from a multidetector CT scanner.

RESULTS

For unilateral vocal cord paralysis, the most sensitive imaging findings were ipsilateral pyriform sinus dilatation, medial positioning and thickening of the ipsilateral aryepiglottic fold, and ipsilateral laryngeal ventricle dilatation. In two patients, coronal reformatted images aided the diagnosis by better showing flattening of the subglottic arch. Imaging findings allowed localization of a central vagal neuropathy in four patients.

CONCLUSION

Three reliable imaging findings associated with vocal cord paralysis were identified on routine axial CT studies: ipsilateral pyriform sinus dilatation, medial positioning and thickening of the ipsilateral aryepiglottic fold, and ipsilateral laryngeal ventricle dilatation. Coronal reformatted images of the larynx may be helpful, but they are not necessary in 95% of patients. Ipsilateral pharyngeal constrictor muscle atrophy is a helpful imaging finding to localize a more central vagal neuropathy. Our findings can aid radiologists in identifying peripheral and central vagal neuropathy in patients who present for CT of the neck who have a normal voice and are without a history suggestive of a vagal problem.

Horner's syndrome following excision of a vagal paraganglionoma

We report a case of excision of a vagal paraganglionoma resulting in Horner's syndrome. The case was initially misdiagnosed as a carotid body tumour and demonstrates the need for adequate preoperative imaging and patient counselling for likely complications of surgery.

Concomitant vagal neurofibroma and aplasia of the internal carotid artery in neurofibromatosis type 1

We report the case of a patient with neurofibromatosis type 1 who had both aplasia of an internal carotid artery (ICA) and a vagal neurofibroma. To our knowledge, this is the first report in the literature of the simultaneous presence of these two rare disorders in a single patient. We believe that this is also the first report of an absence of an ICA in a patient with neurofibromatosis type 1. The patient was a 19-year-old woman who complained of a slowly growing neck mass. The mass occupied the right parapharyngeal space and upper cervical region. The patient had no other masses on physical examination, but widespread café au lait spots were evident. This led us to suspect the presence of a vagal neurofibroma. The tumor was removed, and pathology confirmed the diagnosis. No intracranial aneurysms were detected on cerebral angiography.

Malignant peripheral nerve sheath tumors of intrathoracic vagus nerve

The authors report two cases of malignant peripheral nerve sheath tumors arising from the vagus nerve in the mediastinum in patients who had no stigmata of neurofibromatosis (von Recklinghausen's disease). Computed tomography showed homogeneous soft tissue masses, with minimal calcification seen in one patient. T2-weighted magnetic resonance images showed regions of low signal intensity caused by a dense cellular population.

Cervical paragangliomas: diagnosis, management and complications

Sixteen patients were diagnosed as suffering from cervical paragangliomas. Eleven patients (68.75 per cent) had twelve carotid paragangliomas (CPs), and five patients (31.25 per cent) had six vagal paragangliomas (VP). One CP (8.33 per cent) originated from paraganglia around the common carotid artery (CCA). Three cases of multiple paragangliomas are presented (18.75 per cent). In 80 per cent (4/5) of VP patients there was widening of the carotid bifurcation similar to that seen with CP. This widening occurred whenever the VP was large enough to grown in between the external carotid artery and internal carotid artery (ECA and ICA). Large VPs may displace the vessels either anterolaterally or anteromedially. Knowledge of the direction of the carotid displacement is essential to avoid intra-operative vascular injuries. Colour flow doppler ultrasound (CFD-US) was found to be a good non-invasive method for diagnosis of vascular neck swellings. It enabled the diagnosis of CP with 100 per cent accuracy, but it was not sufficient for diagnosis of high VP. A transcervical approach, cutting the digastric muscle and the styloid process with the attached ligaments and muscles, was sufficient for excision of most VP. However, midline mandibulotomy might be necessary with high VP. Vascular injuries occurred in 12.5 per cent (2/16) of patients. Superior laryngeal nerve and hypoglossal nerve paralysis occurred, respectively, in (2/11) and (1/11) of patients with CP. Vagal paralysis occurred in all patients with VP. Cerebrovascular accident and post-operative death occurred in one patient (6.26 per cent).

Sonography of the cervical vagus nerve: normal appearance and abnormal findings

OBJECTIVE

The purpose of this study was to assess the appearance of the cervical vagus nerve in healthy individuals and to investigate the potential role of sonography in revealing neck masses that cause vagal dysfunction.

SUBJECTS AND METHODS

We examined 150 consecutive patients. In 144 patients the presence of thyroid, salivary gland, or lymph node disease was suspected. In three patients a cervical mass was palpable, and three patients had symptoms of dysfunction of the inferior laryngeal or vagal nerves. The pathologic diagnoses of the masses were obtained at biopsy.

RESULTS

In 144 individuals the normal vagus nerve was recognized on each side of the neck as a thin band that occupied the posterior angle formed by the common carotid artery and the internal jugular vein. Three patients had tumors arising from the vagus nerve: one neurofibroma, one neurinoma, and one chemodectoma. These tumors were located in the neurovascular bundle and posterior to the vessels; their origin from the vagus nerve was clearly visible in all patients because of the contiguity of the mass with the nerve bundle. In the other three patients, sonography revealed an extrinsic mass that compressed and displaced the vagus nerve out of its longitudinal axis; two cases were hyperplastic nodules of the thyroid, and in one case the nodule was a branchial cyst.

CONCLUSION

Sonography can reveal the vagus nerve in healthy conditions and correctly reveal the vagal origin of some tumors in the parapharyngeal spaces.

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.