Clinical characteristics and treatment outcome for nonvestibular schwannomas of the head and neck

A comparative study of transcervical, endoscope-assisted transcervical, and endoscope-assisted transoral resection of retrostyloid space schwannomas

BACKGROUND

The aim of this retrospective study was to compare the efficacy of transcervical (TC), endoscope-assisted transoral (TO), and endoscope-assisted TC for resection of retrostyloid space schwannomas.

METHODS

The study included patients who underwent complete resection of schwannomas by only one surgical approach. The data we collected included tumor size, estimated blood loss, postoperative complications, and so on. Statistical analysis was performed using one-way analysis of variance and Fisher's exact test.

RESULTS

The study collected 85 patients with tumors mostly located at the oropharyngeal level who were followed up 6 months at least. The results showed that endoscope-assisted TO had certain advantages over others. Additionally, the endoscope-assisted TO set the lowest incidence of neurological complications.

CONCLUSION

Our findings demonstrate that for team with rich experience in the skull base surgery, endoscope-assisted TO is a superior option compared to the other two groups for resection of retrostyloid space schwannomas, with the better preservation of neurological function.

Esophageal schwannoma mimicking non-functional parathyroid adenoma on 99mTc-sestamibi imaging: a case report

Technetium-99m sestamibi single-photon emission computed tomography/computed tomography (99mTc-sestamibi SPECT/CT) is a mainstay of the pre-operative localization of parathyroid lesions. We report here the case of a 30 year-old woman with a fortuitously discovered 2 cm cervical mass for which a parathyroid origin was originally suspected due to its retro-thyroidal localization and a personal history of nephrolithiasis. Normal serum calcium and parathyroid hormone (PTH) levels excluded primary hyperparathyroidism, raising suspicion of a non-functional parathyroid adenoma, and SPECT/CT imaging showed that the mass was 99mTc-sestamibi-avid. Fine-needle aspiration (FNA) was performed; cytology was non-diagnostic but the needle washout was negative for thyroglobulin, calcitonin and PTH, arguing against a thyroidal or parathyroidal origin of the mass. Core needle biopsy revealed a schwannoma, ostensibly originating from the recurrent laryngeal nerve; upon surgical resection, it was finally found to arise from the esophageal submucosa. This case illustrates the fact that endocrinologists, radiologists, nuclear medicine, head and neck, and other specialists investigating patients with cervical masses should be aware that schwannomas need to be considered in the differential diagnosis of focal 99mTc-sestamibi uptake in the neck region.

Surgical management of large lower cranial nerves schwannomas: long term results of a less aggressive resection strategy

In an effort to reduce the high morbidity and life-threatening complications after radical resection in large schwannoma surgery, alternative strategies of nontotal resections have emerged. To evaluate the long term clinical and oncological outcome after lower cranial nerves (LCN) schwannoma surgery operated on with a cranial nerve-sparing technique. Single center retrospective cohort study of 8 consecutive patients harboring LCN schwannomas operated on between March 2005 and October 2021. The mean LCN schwannoma diameter was 33 mm (range 26-51). Seven patients (87,5%) underwent a modified retrosigmoid approach. Three patients underwent gross total resection (37,5%), 3 had received neartotal resection (mean tumor residue 0,25 cc) and subtotal resection in 2 patients who presented with an extracranial extension of the tumor (mean tumor residue 2,44 cc). Both patients had received upfront additional GKRS. The three patients who presented with preoperative CN IX & X injuries recovered within 6 months after surgery. All of the five patients freed from any preoperative CNs IX & X symptoms experienced transient (80%) or definitive (one patient) disturbances after surgery. They all improved within 6 months but one who required long term gastrostomy feeding tube. This patient harbored a schwannoma originating from the glossopharyngeal nerve, which could not be anatomically preserved during surgery. Tumor control was achieved in 100% of cases with a mean follow-up of 91 months. LCN schwannomas could be surgically removed through a less aggressive non-radical resection strategy with acceptable functional results and excellent tumor control.

Pediatric Infraorbital Nerve schwannoma-A Rare Case Report

Infraorbital nerve schwannoma is an infrequent entity that is rarely reported in the paediatric population. This case report is a summed-up report of this infrequent diagnosis, its presentation, and management from an otorhinolaryngologist's perspective. It is reported here for its rarity, inherent surgical challenge, and academic interest. We report a case of a 13-year-old boy with infraorbital nerve schwannoma arising from its two terminal branches. We performed its surgical excision without any disabling deformity. The peculiarity of this case gives insight into the varied presentation of schwannoma. It is important to identify such cases with a high degree of suspicion and treat them accordingly.

Interest in the Endoscopic Endonasal Route as Access to the Parapharyngeal Space for Cervical Sympathetic Chain Schwannoma Resection: A Case Report

Schwannomas are tumors originating from Schwann cells, about 45% of them are located in the head and neck region, including the parapharyngeal space (PFS). Vagus nerve schwannomas (VS) and cervical sympathetic chain schwannomas (CSCS) are most commonly found in this region. We present a case of CSCS located in the PFS of a middle-aged female patient who had surgery with the endoscopic endonasal approach (EEA). There have been no earlier reports of CSCS resection utilizing EEA, according to our literature search. To our knowledge, there is no scientific record of CSCS resection using EEA.

Purely Endonasal Endoscopic Approaches for Extracranial Trigeminal Nerve Schwannoma

OBJECTIVE

The aim of this study is to assess the effectiveness and safety of purely endonasal endoscopic resection of extracranial trigeminal schwannomas (TGSs), with assessment of surgical and clinical outcomes in order to identify optimal candidates for an endonasal endoscopic approach (EEA).

METHODS

A retrospective review of patient's records operated for TGSs between 2008 and 2021 was conducted. Patients operated with a purely EEA were included in this study. Pictures from a frozen fresh cadaver head dissection were used to demonstrate the surgical approach and to show anatomic relationships, complexity of the surgical area and safe corridors for surgery.

RESULTS

A total of 5 patients (4 females and 1 male) were operated for TGS. All patients had facial numbness (100%) as a presenting symptom, followed by facial pain in 2 patients (40%), and orbital pain in 1 (20%). Also, 3 patients (60%) had a tumor originating at the level of the foramen ovale and 2 (40%) at the foramen rotundum. The mean tumor diameter was 3,7 ± 2 cm. Gross total resection were achieved in all cases. Postoperatively, 1 patient had severe mastication problems, 1 had blurred vision, and in the long-term follow-up, 1 had frontal sinusitis. The mean follow up was 106.6 (min:49, max:132, SD: 29.82) months. No recurrences were detected.

CONCLUSIONS

In cases with the extradural TGS having limited extension into Posterior Cranial Fossa, or located in the Middle Cranial Fossa, a purely EEA is possible even for tumors bigger in size. Unilateral endonasal corridors are adequate for resection in most cases.

A Rare Case of Cervical Vagus Nerve Schwannoma in an Adult Patient

Schwannomas of the head and neck are relatively rare benign tumors that derive from the Schwann cells. Schwannomas are usually asymptomatic; however, tumors of bigger size may produce unspecific symptoms due to compression of the adjacent anatomic structures. Vagus nerve schwannomas may present as solitary neck masses, produce hoarseness of voice, or induce paroxysmal cough on palpation, which is also pathognomonic. Preoperative diagnosis is challenging and imaging studies may play a vital role in the diagnosis. Surgical treatment with complete tumor removal is the treatment of choice. In this study, we present a case of vagus nerve schwannoma in an adult male patient.

Pre-operative embolization and excision of vagal schwannoma with rich vascular supply: A case report and literature review

RATIONALE

Schwannomas are benign tumors wrapped in the nerve sheath and can originate from the myelin sheath of the cranial nerve. In previous literature reports, most of the tumors were solid tumors, which can be removed only by surgery. This case report describes a unique case of vagal schwannoma, which, unlike previous cases, involves a dominant arterial supply, and discusses the pre-operative evaluation, relevant radiographic findings, and surgical process of the case in detail.

PATIENT CONCERNS

A 31-year-old woman sought treatment for pain in the left side of the neck when turning her head. A mass on the left side of the neck was found on enhanced computed tomography with a maximum diameter of 6.8 cm, along with multiple tortuous, thickened vascular shadows, and pressure on the left pharyngeal cavity.

DIAGNOSIS

The pathological results showed schwannoma.

INTERVENTIONS

Considering the unusual size of the tumor and thickened blood vessels revealed by pre-operative computed tomography, general anesthesia and biopsy were conducted first to confirm the diagnosis. Excessive bleeding occurred during the process; thus, the tumor was only partially removed before the wound closed after hemostasis. Digital subtraction angiography indicated that the tumor was supplied by multiple arteries, and the tumor was removed by pre-operative embolization plus intra-operative removal.

OUTCOMES

Combined with embolization and surgical resection, the tumor was completely removed, the nerve was partially preserved, and the patient had postoperative hoarseness.

LESSON

The present case indicates the possibility of vascularly supplied vagal schwannoma; thus, it is necessary to conduct pre-operative digital subtraction angiography.

Peripheral facial nerve schwannoma at the inferior mandibular margin: a case report

Schwannomas commonly occur in the head and neck region as acoustic neuromas. Facial nerve schwannomas are rare and usually occur in the temporal region. A 57-year-old woman presented with a mass at the right mandibular margin. Magnetic resonance imaging revealed a schwannoma located immediately caudal to the mental foramen. We were initially uncertain whether it arose from the trigeminal nerve or the facial nerve. Excision was performed under general anesthesia. The mass was encapsulated and easily detached from the surrounding tissue. The nerve of origin was identified proximal to the tumor. A facial nerve origin was confirmed as the muscles supplied by the marginal mandibular branch of the facial nerve moved on nerve stimulation. Nerve fibers were not found distal to the tumor, possibly because they had been cut during excision. We believe that this is the first report of a schwannoma arising from the peripheral facial nerve.

Intraconal Retro-Orbital B-Type Antoni Neurinoma Causing Vision Loss

Schwannoma is a rare benign tumor, originating from Schwann cells of the peripheral nerve sheath. We describe a case of intraconal orbital schwannoma, causing compression to the optic nerve and progressive visual impairment treated with surgical resection. The diagnosis of benign orbital schwannoma was provided by histopathological examination (large spindle cell tumor with AntoniB-type cell pattern) and also with immunohistochemistry (positivity for S-100 protein). The 6 months' follow-up was performed. The patient was asymptomatic during the 6-month follow-up.

Schwannomas of Uncommon Peripheral Locations: Analysis of Imaging Findings of 21 Cases

BACKGROUND

Schwannomas are benign slow-growing tumors most often associated with the cranial nerves. Schwannomas often originate from the eighth cranial nerve. They may also originate from the peripheral nervous system of the neck and extremities. However extracranial peripheral schwannomas are considered a rare entity.

OBJECTIVES

The knowledge of rare localizations and typical imaging findings will lead to a successfulradiological diagnosis. Therefore, in this study, we present the clinical findings and MRI characteristics of schwannomas with a rare localization involving the peripheral, lower and upper extremity and intramuscular regions.

MATERIALS AND METHODS

The hospital database was screened for patients with an extracranial soft tissue mass. Twenty-one cases of schwannomas were found in rare localization. We analyzed the MR images of these patients retrospectively. The MR images were evaluated in terms of tumor location, signal intensity, and enhancement pattern. The histological examination of all the patients confirmed the diagnosis of schwannoma.

RESULTS

In 21 patients, the schwannomas were peripheral, localized to upper (n = 6) and lower extremities (n = 11). The remaining four patients had intramuscular schwannomas. The patients diagnosed with intramuscular schwannomas had schwannomas in sternocleidomastoid, gastrocnemius, triceps muscle and lateral wall of the abdomen. The average long-axis diameter of the tumor was 27.7 mm and the average short-axis diameter was 16.4 mm. The contrast pattern was diffused in eight tumors and peripheral in 13.

CONCLUSION

In this study, we present clinical findings and MRI characteristics of schwannomas with a rare localization involving the peripheral, lower and upper extremity and intramuscular regions.

Intramasseteric schwannoma treated with facelift incision and retrograde facial nerve dissection

Schwannoma is a slow-growing, well-demarcated, benign soft tissue tumor of the peripheral nerve sheath. It commonly develops in the head and neck region, usually in the parapharyngeal space. In this case, a 42-year-old woman visited the outpatient department to manage a painless mass on her left cheek. She had no history of concern and no neurological symptoms were observed. In the enhanced computed tomography scan, a 2.8 × 2.8 × 1.8 cm, heterogeneously enhanced tumor was detected in the left masseter muscle. A tumor resection under general anesthesia was planned. For the resection, a facelift incision was chosen; branches of the facial nerve were identified and retrogradely dissected. A well-marginated, yellowish, solid mass was found in the left masseter muscle. The mass was excised and given a histopathological diagnosis of schwannoma. A definite diagnosis of schwannoma, originating in the masseter muscle, is difficult to arrive at with radiographic findings alone; it is often misdiagnosed as intramuscular hemangioma. Histopathological examinations, including fine-needle aspiration or histological biopsy after surgery, are necessary. Using a facelift incision with retrograde facial nerve dissection, tumor resection in an intramasseteric lesion can be performed efficiently, without nerve damage, or leaving conspicuous scars on the face.

CO₂ Laser for the Treatment of Auricle Schwannoma: A Case Report and Review of the Literature

BACKGROUND Schwannoma, also called neuroma or neurolemmoma, is a tumor originating from the Schwann cells surrounding the nerves. It is an isolated benign tumor and its transformation into malignant cancer is very rare. Relatively uncommon, it is only the 5% of all the tumors of soft tissues. Its localization in the head and neck region accounts for up to 25-45% of schwannomas. In the outer ear, it commonly involves the external auditory canal, while auricle and tympanic membranes are very rare localizations of schwannomas. CASE REPORT We report a case of a 23-year-old male with a 3-year medical history of a growing neoplasm located in the left auricle concha, which was treated with a carbon dioxide laser (CO₂ laser) under local anesthesia. CONCLUSIONS Using a CO₂ laser allowed us to easily remove the tumor, reduce bleeding and surgical time, and avoid sutures and thus unsightly scars on the face. No complications and no relapse at 5 years of follow-up occurred.

Intraparotid facial nerve schwannoma: two case reports and a review of the literature

SUMMARY

Schwannomas are rare benign tumours that arise from Schwann cells. The most known and studied is the intracranial vestibular schwannoma, even if it is not the most frequent. More often schwannomas arise from peripheral sensitive nerves, and the vagous is most involved among the cranial nerves. Intraparotid schwannomas account for just 10% of all facial involvement, so they are an extremely rare localisation. At present, there are less than 100 cases described in the literature. We performed a retrospective analysis of parotidectomy in two Italian hospitals and present two cases of intraparotid schwannoma and a review of the literature. In the first case, we performed a parotidectomy with a stripping of tumour from the nerve. In the other case, a hypoglossal-facial neurorrhaphy was performed. Follow-up was 24 months in the first (House-Brackmann II degree in temporal-ocular and III in facial-cervical branches) and 30 months in the second case (House-Brackmann III degree in both temporal-ocular and facial-cervical branches). Preoperative diagnosis of facial nerve schwannoma is a challenge; however, it is extremely important since post-operative palsy is common and often higher grade. Unfortunately, schwannoma has similar radiologic finding as more common pleomorphic adenoma and often FNAC is not helpful. Due to its rarity and benign nature, there is debate in the literature on the need for surgical removal. Wait-and-see is a valid option, but may could give problems in secondary surgery. Stripping or near-total removal can be useful in cases of limited involvement of the nerve. Neurorrhaphy can provide good functional results when facial sacrifice is needed.

Vagal schwannomas of the head and neck: A comprehensive review and a novel approach to preserving vocal cord innervation and function

BACKGROUND

Schwannomas, benign tumors arising from neurolemmocytes, are the most common type of peripheral nerve tumors. Extracranial schwannomas are most often found in the parapharyngeal space, commonly involving the vagus nerve to cervical sympathetic trunk. Vagal schwannomas present several unique clinical and therapeutic challenges.

METHODS

A comprehensive literature review was conducted on 197 articles reporting 235 cases of cervical vagal schwannomas. Presenting symptoms, treatment approach, and postoperative outcomes were recorded and analyzed.

RESULTS

Vagal schwannomas commonly present as asymptomatic neck masses. When they become symptomatic, surgical resection is the standard of care. Gross total resection is associated with higher postoperative morbidity compared to subtotal resection. Initial reports using intraoperative nerve monitoring have shown improved nerve preservation. Recurrence rates are low.

CONCLUSION

The combination of intermittent nerve mapping with novel continuous vagal nerve monitoring techniques may reduce postoperative morbidity and could represent the future standard of care for vagal schwannoma treatment.

Vidian Nerve Schwannoma: A Rare Skull-Base Neoplasm Presenting with Ocular Manifestations: A Case Report and Literature Review

INTRODUCTION

Vidian nerve schwannomas are exceedingly rare, with only 7 cases reported since 2006. Patients presenting with ocular symptoms have been reported in only 1 case.

CASE PRESENTATION

A 54-year-old woman presented with a 3-month history of right periorbital pressure, third cranial nerve palsy, and visual field defect. Imaging results showed a right sphenoid skull-base mass with obliteration of the vidian canal that extended into the pterygopalatine fossa. The patient underwent an extended endoscopic resection with pterygopalatine fossa dissection. Pathologic findings demonstrated a schwannoma.

DISCUSSION

A literature review showed that this is the second reported case of a vidian nerve schwannoma presenting with ocular symptoms and that endoscopic resections are becoming the standard of care. Practitioners should be aware that vidian nerve schwannomas can present as a skull-base mass with predominantly ocular symptoms, including vision loss, secondary to mass effect. Consideration should be given to this entity in the setting of typical radiographic and histopathologic characteristics. Endoscopic approaches to resection are safe and have low morbidity.

Hypoglossal canal schwannoma causing isolated left 12th cranial nerve palsy

A 40-year-old woman presented with insidious onset, gradually progressive dysarthria and inability to manoeuvre bolus of food in her mouth while eating. The duration of her symptoms was 3 months. On evaluation, the left half of her tongue was wasted. The tongue deviated to the left on protrusion. There were no clinical features suggestive of involvement of the ipsilateral 9th, 10th or 11th cranial nerves. MRI of the brain showed a large, fusiform lesion in the left hypoglossal canal, extending into the jugular canal. The lesion was surgically excised and found to be a schwannoma.

A novel technique to identify the nerve of origin in head and neck schwannomas

Objective:

Identifying the nerve of origin in head and neck schwannomas is a diagnostic challenge. Surgical management leads to a risk of permanent deficit. Accurate identification of the nerve would improve operative planning and patient counselling.

Methods:

Three patients with head and neck schwannomas underwent a diagnostic procedure hypothesised to identify the nerve of origin. The masses were infiltrated with 1 per cent lidocaine solution, and the patients were observed for neurological deficits.

Results:

All three patients experienced temporary loss of nerve function after lidocaine injection. Facial nerve palsy, voice changes with documented unilateral same-side vocal fold paralysis, and numbness in the distribution of the maxillary nerve (V2), respectively, led to a likely identification of the nerve of origin.

Conclusion:

Injection of lidocaine into a schwannoma is a safe, in-office procedure that produces a temporary nerve deficit, which may enable accurate identification of the nerve of origin of a schwannoma. Identifying the nerve of origin enhances operative planning and patient counselling.

Intramasseteric Schwanoma mimicking an isolated cheek mass: Case report and review of literature

INTRODUCTION

Schwannoma is a benign well circumscribed tumor of the nerve sheath and it is mostly localized in the head and neck. Intramasseteric schwannoma represents a very rare entity and a few cases have been described in the literature.

PRESENTATION OF CASE

We present a case of an isolated, asymptomatic and slowly progressive right cheek tumor in a middle aged man. Although multiple investigations, including neck scanner and fine needle aspiration, were done, the diagnosis was obscure and difficult before definite surgical resection. Surgery showed an isolated and well-defined tumor inside the masseter muscle which was completely resected. Histopathologic finding confirmed the diagnosis of schwannoma with the characteristic Antoni A and Antoni B cells.

DISCUSSION

Among benign tumors of the peripheral nerves, schwannoma is a specific type that originates from Schwann cells. It is typically slowly growing, neoplasm that is displacing neural structures without direct invasion. History, physical examination, fine needle aspiration, and magnetic resonance imaging are used as diagnostic modalities, however definitive diagnosis and identification of the affected nerve are often difficult up to the time of surgery.

CONCLUSION

Herby we describe a very rare localization of schwannoma arising from masseter muscle in a 30 year old man who presents with painless neck mass. This rare entity should be considered in the differential diagnosis in any patient presented with cheek mass.

A Case of Vulvar Schwannoma Mimicking Epidermoid Cyst

Schwannoma is a generally benign tumor of the peripheral nerve sheath arising from Schwann cells. Most schwannomas are found on the head and neck. Here, we describe a rare case of benign vulvar schwannoma located at the labium majus which was similar to an epidermoid cyst in clinical appearance.

Subcutaneous Schwannoma in the Head Region

Schwannoma is a benign neural tumor derived from Schwann cells surrounding the nerves. It occurs primarily in subcutaneous tissues and muscles with a tendency for distal extremities, head, and neck area. Treatment of schwannoma is surgical excision. Lipomas are the most common soft-tissue lesions. A case is presented to increase awareness on differential diagnosis of head and neck subcutaneous masses.

Orbital Frontal Nerve Schwannoma-Distinctive Radiological Features

PURPOSE

To review the radiological findings of frontal nerve schwannoma of the orbit and determine distinguishing imaging features.

DESIGN

Retrospective interventional case series.

METHODS

Setting: Single tertiary institution.

PERIOD

September 1996 to December 2016.

PATIENT POPULATION

Thirteen patients with orbital frontal nerve schwannoma.

INTERVENTION

Patients underwent surgical excision following preoperative imaging.

MAIN OUTCOME MEASURES

Imaging characteristics on computed tomography (CT) and magnetic resonance imaging (MRI).

RESULTS

There were 13 patients with histopathologically proven schwannoma of the frontal nerve. Mean age was 44.4 years and 61.5% were male. The majority (84.6%) of frontal nerve schwannomas extended between the supraorbital notch and superior orbital fissure. The most common shape seen in our patients with frontal nerve schwannoma was a multilobulated "beaded" appearance (46.2%), followed by a dumbbell (30.8%), oval (15.4%), and fusiform (7.7%) shape. On CT imaging, all patients had bony remodeling. Target sign, fascicular sign, and cystic degeneration were seen in 76.9%, 35.8%, and 46.2% of patients, respectively. On radiological-pathologic correlation, the zone of tightly packed cellular solid portion (Antoni A pattern) corresponded to the hypointense area on T2-weighted MRI and the hyperintense area on gadolinium-enhanced T1-weighted MRI.

CONCLUSION

Frontal nerve schwannoma should be considered as a differential diagnosis for any superior orbital mass. Our study describes several radiological findings that would point toward its diagnosis, including its multilobulated beaded or dumbbell shape, as well as additional signs such as the target sign, fascicular sign, and cystic degeneration.

Parapharyngeal Schwannoma of the Mandibular Nerve Associated With Auditory Changes

We present a case of a parapharyngeal schwannoma of the mandibular nerve with intraosseous extension into the mandible. The initial symptoms included decreased auditory acuity, with subsequent magnetic resonance imaging findings suggestive of Eustachian tube obstruction. This represents a rare symptom of schwannomas of the mandibular nerve. Owing to the degree of bony expansion and cortical thinning of the adjacent mandibular ramus, concern existed for a pathologic fracture. Treatment involved complete excision of the lesion using hemimandibulectomy with second stage reconstruction. The patient noted resolution of the preoperative symptoms. No sign of recurrence of the schwannoma was noted at the 2-year mark.

Volumetric Growth of Cervical Schwannoma as a Predictor of Surgical Intervention

Objective

Cervical schwannomas are benign tumors that commonly present as asymptomatic masses and are managed with observation, radiation, or surgery. To our knowledge, the rate of volumetric change seen on serial imaging is not currently used to determine surgical candidacy. We assess average growth rates and determine whether growth rate of cervical schwannoma predicts having undergone surgery.

Study Design

Case series with chart review.

Setting

Quaternary academic medical center.

Subjects and Methods

Patients were identified with at least 2 imaging studies and pathologic or imaging characteristics of cervical schwannoma. Volume was calculated with the formula 4/3π xyz, with x, y, and z representing the 3 orthogonal dimensions. Volume and rate of volume change were compared among observed, surgical, and gamma knife groups.

Results

Thirteen patients were identified and divided into subgroups: surgical (n = 5), observation (n = 6), and gamma knife (n = 2). Mean follow-up time was 21 months (range, 1-80 months) and not significantly different among subgroups. The average changes in volume were 3.61 cm3/mo (entire group), –2.75 cm3/mo (observation), 11.97 cm3/mo (surgery), and 1.78 cm3/mo (gamma knife). Average initial volume for the entire group was 124.4 cm3 (range, 5-608 cm3) and 142 cm3 (range 5-613) at follow-up. The surgical group had a statistically significant change in volume ( P = .03). A statistically significant difference in growth rate was seen between the surgical and observation groups ( P = .016) and between the surgical group and all nonsurgical patients ( P = .011).

Conclusions

Rate of tumor growth can be used in the evaluation of patients with cervical schwannoma, and it may predict surgical intervention.

Color Doppler Ultrasound in Diagnosis and Assessment of Carotid Body Tumors: Comparison with Computed Tomography Angiography

A carotid body tumor (CBT) is a rare, non-chromaffin paraganglioma, and its diagnosis mainly depends on imaging modalities. The aim of this study was to investigate the ability of color Doppler ultrasound (CDU) in the diagnosis and assessment of CBT based on computed tomography (CT). We retrospectively reviewed the CDU and CT features of 49 consecutive CBTs and 23 schwannomas from 67 patients and compared these findings with surgical resection specimens. The mean size of CBT lesions on ultrasound scans and CT angiography (CTA) was 3.24 cm ± 0.82 cm (range, 1.6-5.2 cm) and 3.84 cm ± 1.08 cm (range, 1.8-6.8 cm), respectively, which had statistically significant difference (t = 9.815, p = 0.000). The vascularity of CBT lesions was richer than that of schwannoma lesions (p < 0.05). Intra-lesional vascularities feeding CBT mostly arose from the external carotid artery and had spectrum characteristics including low velocity and resistance. Peak systolic velocity (PSV) and resistance index (RI) of the vasa vasorum were 39.8 cm/s ± 19.8 cm/s and 0.54 ± 0.06, respectively. There was the correlation between CTA and CDU in identifying Shamblin type I CBT lesions, while CTA technique was superior for CDU, identifying Shamblin type II and III CBT lesions. Accuracy, specificity and sensitivity of CDU in diagnosing CBTs were 87.5% (63 of 72), 82.6% (19 of 23) and 89.8% (44 of 49), respectively. Both accuracy and sensitivity of CTA in diagnosing CBTs were 100%. CDU can be useful for assessment of Shamblin's type and intra-lesional blood flow of CBTs before its metastases, while CT imaging can reveal the relationship between lesions and adjacent arteries, as well as the involvement of the skull base. CDU combined with CT imaging can be used as an optimal detection modality for the assessment and management of CBT.

Extracranial schwannoma in the carotid space: A retrospective review of 91 cases

BACKGROUND

Schwannomas of the vagus nerve and cervical sympathetic nerve are rare; hence, only limited information exists regarding their diagnosis and clinical management.

METHODS

We conducted a retrospective review of the clinical features, imaging studies, and treatment results of patients with schwannoma of the vagus nerve and schwannoma of the sympathetic nerve.

RESULTS

Of 91 patients, 91% (n = 83) were preoperatively diagnosed with schwannoma tumors. Using the hyoid bone as an anatomic landmark, the location of the schwannoma of the vagus nerve in the carotid space was significantly different to the location of schwannoma of the sympathetic nerve (p = .003). Although 52 of the 76 patients followed up (68%) had postoperative nerve weaknesses, 13 patients (50%) and 14 patients (53.8%), respectively, fully recovered from schwannoma of the vagus nerve and schwannoma of the sympathetic nerve.

CONCLUSION

In the carotid space, schwannomas of the vagus nerve are usually located below the hyoid bone, whereas schwannomas of the sympathetic nerve more commonly arise from the suprahyoid compartment. Accurate preoperative diagnosis and the intracapsular enucleation surgical approach decreased the incidence of postoperative morbidity. © 2016 Wiley Periodicals, Head Neck 39: 42-47, 2017.

Preoperative diagnosis of vagal and sympathetic cervical schwannomas based on radiographic findings

OBJECTIVE Vagus nerve and sympathetic chain cervical schwannomas (VNCSs and SCCSs) are benign nerve sheath tumors that arise in the head and neck. Despite similar presentations that make accurate preoperative diagnosis more difficult, the potential for morbidity following resection is significantly higher for patients with VNCS. Therefore, the authors analyzed a retrospective case series and performed a comparative analysis of the literature to establish diagnostic criteria to facilitate more accurate preoperative diagnoses. METHODS The authors conducted a blinded review of imaging studies from retrospectively collected, operatively confirmed cases of VNCS and SCCS. They also performed a systematic review of published series that reported patient-specific preoperative imaging findings in VNCS or SCCS. RESULTS Nine patients with VNCS and 11 with SCCS were identified. In the study cohort, splaying of the internal carotid artery (ICA) and internal jugular vein (IJV) did not significantly predict the nerve of origin (p = 0.06); however, medial and lateral ICA displacement were significantly associated with VNCS and SCCS, respectively (p = 0.01 and p = 0.003, respectively). Multivariate analysis demonstrated that ICA and IJV splaying with medial ICA displacement carried an 86% probability of VNCS (p = 0.001), while the absence of splaying with lateral ICA displacement carried a 91% probability of SCCS (p = 0.006). The presence of vocal cord symptoms or peripheral enhancement significantly augmented the predictive probability of VNCS, as did Horner's syndrome or homogeneous enhancement for SCCS. A review of the literature produced 25 publications that incorporated a total of 106 patients, including the present series. Splaying of the ICA and IJV was significantly, but not uniquely, associated with VNCS (p < 0.0001); multivariate analysis demonstrated that ICA and IJV splaying with medial ICA displacement carries a 75% probability of VNCS (p < 0.0001), while the absence of such splaying with lateral ICA displacement carries an 87% probability of SCCS (p = 0.0003). CONCLUSIONS ICA and IJV splaying frequently predicts VNCS; however, this finding is also commonly observed in SCCS and, among the 9 cases in the present study, was observed more often than previously reported. When congruent with splaying, medial or lateral ICA displacement significantly enhances the reliability of preoperative predictions, empowering more accurate prognostication.

Laryngeal schwannoma: a systematic review

A large proportion of schwannomas are found in the head and neck region. Schwannoma located within the larynx however is uncommon. The characteristic features, clinical presentations, treatment and the outcomes of patients with laryngeal schwannoma are therefore not clearly understood. The aim of this comprehensive review is to compile, analyze and present the details to develop a consensus and augment the available literature on laryngeal schwannoma. A comprehensive literature search on laryngeal schwannoma was performed on PUBMED/MEDLINE, EMBASE, CINAHL and Science Citation Index using MeSH words. A total of 55 patients were reviewed in this study. 40.7 % of the tumours arose from the aryepiglottic fold or arytenoids. Other areas where tumours were found included the false cord, true vocal cord, epiglottis, subglottis, piriform sinus and the post cricoid area. 64.9 % patients presented with dysphonia. Others typically present with multiple symptoms related to the mass effect and location of the tumour. All patients were managed surgically with different techniques and approaches. Majority of patients were alive with no residual disease. There were five recurrences and no mortality to date. Schwannoma within the larynx can present with a variety of symptoms. Surgical excision remained as the treatment of choice with good overall prognosis.

Schwannoma of the Orbit

Background

A schwannoma is a benign, slow-growing peripheral nerve sheath tumor that originates from Schwann cells. Orbital schwannomas are rare, accounting for only 1% of all orbital neoplasms. In this study, we retrospectively review orbital schwannomas and characterize clinical, radiologic, and histologic features of this rare entity.

Methods

A retrospective review was performed to identify patients with histologically confirmed orbital schwannoma, among a list of 437 patients who had visited our hospital with soft tissue masses within the orbit as the primary presentation between 2010 and 2014. Patient charts and medical records were reviewed for demographic information, relevant medical and family history, physical examination findings relating to ocular and extraocular sensorimotor function, operative details, postoperative complications, pathologic report, and recurrence.

Results

Five patients (5/437, 1.1%) were identified as having histologically confirmed orbital schwannoma and underwent complete excision. Both computed tomography (CT) and magnetic resonance imaging (MRI) studies were not consistent in predicting histologic diagnosis. There were no complications, and none of the patients experienced significant scar formation. In two cases, patients exhibited a mild postoperative numbness of the forehead, but the patients demonstrated full recovery of sensation within 3 months after the operation. None of the five patients have experienced recurrence.

Conclusion

Orbital schwannomas are relatively rare tumors. Preoperative diagnosis is difficult because of its variable presentation and location. Appropriate early assessment of orbital tumors by CT or MRI and prompt management is warranted to prevent the development of severe complications. Therefore, orbital schwannomas should be considered in the differential diagnosis of slow-growing orbital masses.

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.

A Rare Finding of Schwannoma of the Vidian Canal: A Case Report

Background Schwannomas of the vidian canal are an extremely rare type of intracranial tumor that can have variable clinical presentations including headache, facial pain, facial muscle paralysis, decreased lacrimation, or nasal dryness. We present an atypical case of an incidentally identified asymptomatic vidian canal schwannoma.

Case Description A 49-year-old woman with a history of multiple sclerosis presented for routine surveillance magnetic resonance imaging that detected an ovoid mass originating in the vidian canal. Given the unusual location of the lesion, an endoscopic endonasal biopsy was performed and confirmed the diagnosis of a vidian canal schwannoma, for which the patient chose to receive fractionated radiation therapy.

Conclusion When a vidian canal tumor is identified, endoscopic endonasal biopsy can be used to confirm the diagnosis before pursuing either surgical or radiotherapy treatment. In particular, fractionated radiation therapy offers a radiobiologically safe means of delivering radiation when there is concern for late radiation-related side effects following treatment completion.

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.

A case of malignant peripheral nerve sheath tumor of the hypoglossal nerve after stereotactic radiosurgery treatment

Objectives Hypoglossal schwannomas are rare. Surgical resection has been the standard treatment modality. Radiosurgery has been increasingly used for treatment. Radiation-associated secondary malignancy/malignant transformation has not been documented in the literature for the treatment of nonvestibular schwannomas. Setting The patient was a 52-year-old man with an enlarging high cervical/skull base lesion 8.5 years after CyberKnife treatment of a presumed vagal schwannoma. A decision was made for surgical resection, and the tumor was found to originate from the hypoglossal nerve intraoperatively. Final pathology diagnosis was malignant peripheral nerve sheath tumor. Results Patient had a gross total resection. Three months after resection, he received fractionated radiation of 50 Gy in 25 fractions and a boost gamma knife radiosurgery of 10 Gy to the 50% isodose surface. He remained tumor free on repeat magnetic resonance imaging 9 months after the resection. Conclusion Although extremely rare, radiation treatment of nonvestibular schwannomas can potentially cause malignant transformation.

[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.

Non-vestibular head and neck schwannomas: a 10-year experience

Schwannomas are rare and slow growing tumours, arising from Schwann cells which provide myelin; less than 1% of them degenerate into a malignant state. Although most studies are based on acoustic schwannomas, the majority of these tumours are non-vestibular and extracranial. Up to 45% of them can be localised in head and neck districts, where they represent a diagnostic challenge because they are in differential diagnosis with lipoma, brachial cyst, paraganglioma and adenopathy. Between February 2002 and September 2012 our experience considers 18 patients affected by schwannomas localised in the neck in 14 cases, in the oral cavity in 2 cases, in the upper lip in 1 case and finally in the nose in 1 case. A painless neck mass was the major symptom referred, as well as dysphonia and oral pain. Ultrasound scan with fine needle aspiration biopsy was done in half of the group and was diagnostic in 30%, whereas magnetic resonance imaging was diagnostic in 77%, confirming its primary role in diagnostic work-up. The surgical approach was mainly by cervical incision and the intraneural extracapsular enucleation was the technique used without nerve injury in 89% of cases. Follow-up period was 6-120 months and no evidence of relapse was registered.

Anesthetic management of schwannoma mimicking carotid body tumor

Schwannomas are rare and slow-growing neurogenic tumors for which surgery is the standard of care. However, the anesthetic management of these tumors can be challenging. This case report describes the anesthetic management of a patient who underwent carotid endarterectomy and excision of a presumed carotid body tumor. Histopathologic examination showed that the excised tissue was a schwannoma, which in this location can mimic a carotid body tumor. The relevant literature is also reviewed.

Endoscopic endonasal approach for nonvestibular schwannomas

BACKGROUND

Nonvestibular schwannomas of the skull base often represent a challenge owing to their anatomic location. With improved techniques in endoscopic endonasal skull base surgery, resection of various ventral skull base tumors, including schwannomas, has become possible.

OBJECTIVE

To assess the outcomes of using endoscopic endonasal approach (EEA) for nonvestibular schwannomas of the skull base.

METHODS

Seventeen patients operated on for skull base schwannomas by EEA at the University of Pittsburgh Medical Center from 2003 to 2009 were reviewed.

RESULTS

Three patients underwent combined approaches with retromastoid craniectomy (n = 2) and orbitopterional craniotomy (n = 1). Three patients underwent multistage EEA. The rest received a single EEA operation. Data on degree of resection were found for 15 patients. Gross total resection (n = 9) and near-total (>90%) resection (n = 3) were achieved in 12 patients (80%). There were no tumor recurrences or postoperative cerebrospinal fluid leaks. In 3 of 7 patients with preoperative sensory deficits of trigeminal nerve distribution, there were partial improvements. Patients with preoperative reduced vision (n = 1) and cranial nerve VI or III palsies (n = 3) also showed improvement. Five patients had new postoperative trigeminal nerve deficits: 2 had sensory deficits only, 1 had motor deficit only, and 2 had both motor and sensory deficits. Three of these patients had partial improvement, but 3 developed corneal neurotrophic keratopathy.

CONCLUSION

An EEA provides adequate access for nonvestibular schwannomas invading the skull base, allowing a high degree of resection with a low rate of complications.

Cervical sympathetic chain schwannoma

INTRODUCTION

Cervical schwannoma is a benign peripheral nerve tumor specifically developing from Schwann cells. Cervical sympathetic chain schwannoma is rare. Following a case report, the authors describe its specific radiological and histological characteristics. Treatment is surgical.

CLINICAL CASE

A 56-year-old woman consulted for an isolated left lateral cervical mass of several years' standing, but with recently associated pharyngeal discomfort. Cervical CT revealed a vascularized retrostyloid mass with venous-time enhancement, inducing anterior displacement of the jugulo-carotid axis. The tumor could not be identified on fine-needle aspiration cytology, and surgical resection was performed by cervicotomy. Surgical exploration found a tumor developing from the cervical sympathetic nerve, posterior to the jugular vein and carotid sheath. Histopathologic examination diagnosed schwannoma. Postoperative outcome featured Horner's syndrome.

CONCLUSION

Cervical sympathetic chain schwannoma is a rare benign tumor, to be suspected in the presence of an isolated lateral cervical mass. Preoperative CT is mandatory to guide diagnosis; treatment is surgical, to confirm histologic diagnosis. Postoperative Horner's syndrome often confirms cervical sympathetic chain involvement.

Schwannoma arising from intramasseteric region

Schwannoma in the head and neck is usually arising in the parapharyngeal space, but intramasseteric schwannoma is very rare. We report a schwannoma arising from masseter muscle in a middle-aged woman, who presented with a history of a painless right cheek mass for 3 years. Computed tomography scan suggested that the mass was located within the masseter muscle. Fine-needle aspiration was performed and showed spindle neoplastic cells, which were suspected to be of mesenchymal tissue origin. The mass was completely resected under general anesthesia. It was a well-circumscribed and lobulated mass, 4 × 3 × 2 cm in size. Histological examination gave the diagnosis of schwannoma, which was also confirmed by immunohistochemical stainings for S-100 and vimentin. Neurologic sequelae and recurrence were not found at 2 years after surgery.

[Rare extracranial localizations of the head and neck schwannomas]

INTRODUCTION

Schwannomas are tumors of neurogenic origin, that arise from Schwann cells which surround peripheral, cranial and autonomic nerves. Schwannomas account for only 5% of all benign soft tissue tumors, and 25-45% of extracranial schwannomas are present in the head and neck region. They are usually classified according to the nerve of origin and the site within the head and neck.

CASE REPORT

We presented extremely rare extracranial localizations of schwannomas and discussed about diagnosis and management of these tumors.

CONCLUSION

Schwannomas are slow-growing tumors and late symptoms appearance may cause a delay in diagnosis and treatment of patients with these tumors. An appropriate diagnostic protocol is indispensable tool in performing a differential diagnosis of malignant from benign lesions. Choice of surgical approach depends on schwannomas localization.

Imaging characteristics of schwannoma of the cervical sympathetic chain: a review of 12 cases

BACKGROUND AND PURPOSE

SCSCs are rare. This study reviews our experience with CT and MR imaging of SCSCs.

MATERIALS AND METHODS

We retrospectively reviewed the CT and MR imaging studies as well as clinical data of 12 patients (6 men, 6 women; mean age, 41 years; range, 27-55 years) with surgicopathologic evidence of SCSC, referred to our institution between January 1999 to October 2008. Images were evaluated with respect to the location, number, morphology, attenuation/signal intensity, enhancement characteristics, and patterns of mass effect of the schwannomas.

RESULTS

The schwannomas were solitary, well-circumscribed, and medial to the carotid sheath. Seven were hypoattenuated to skeletal muscle on CT with poor postcontrast enhancement, 4 were isoattenuated, and a single lesion showed intense heterogeneous enhancement. At MR imaging, they were heterogeneously bright on T2WI with intense inhomogeneous postgadolinium enhancement. The ICA was displaced anteriorly in 9 patients with a component of lateral displacement in 8 of these patients. The ICA was in a neutral position in 2 patients and posterolaterally displaced in 1 patient. A single patient demonstrated separation of the ICA and IJV. There was splaying of the carotid bifurcation in 4 patients.

CONCLUSIONS

We present the patterns of mass effect and the spectrum of CT and MR imaging characteristics of SCSC, including certain observations that are infrequently described in the published literature.

Internal jugular vein vascular malformation presenting as mass at root of neck: a case report

Background

We report a case of vascular malformation arising from internal jugular vein presenting as mass at root of neck with no clinical stigmata which to the best of our knowledge is the first reported case of an intrinsic vascular malformation arising from the internal jugular vein. Magnetic resonance imaging features of this new entity have been described.

Case presentation

A 27 year male presented with a gradually enlarging, asymptomatic swelling on left supraclavicular region with normal overlying skin. A soft mass, about 7 × 7 cm with restricted mobility was found with normal cranial nerve function. Fine needle aspiration cytology showed a hemorrhagic aspirate. Doppler showed a mass displacing left carotid artery posteriorly while left internal jugular vein was not visualized. Magnetic resonance imaging showed a well defined mass isointense to hypointense on T1 weighted and hyperintense on T2 weighted and STIR images with fluid-fluid levels. On exploration, a vascular mass arising from left internal jugular vein was found with good tissue planes, which was excised after ligating the patent internal jugular vein above and below the lesion. Histopathologic examination confirmed the diagnosis of vascular malformation.

Conclusion

The diagnosis of intrinsic vascular malformation arising from internal jugular vein should be kept in differential while dealing with masses at root of neck and magnetic resonance imaging features may help in the pre-operative diagnosis of this entity.

The presenting features of middle ear facial nerve sheath tumors: a clinical review

Facial nerve sheath tumors are the most common middle ear benign neoplasms. Four facial nerve sheath tumors in the middle ear were diagnosed in our department over a 12-year period, and we described our experience in the management of these tumors. A thorough review of the English literature on middle ear peripheral nerve sheath tumors has been conducted, and the findings of this review are presented and discussed. We have paid particular attention to the presenting features of these tumors with the aim of enhancing diagnostic ability.