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

doi:10.1016/j.amjoto.2004.08.011

American Journal of Otolaryngology

Volume 26, Issue 2, March–April 2005, Pages 108-112

https://doi.org/10.1016/j.amjoto.2004.08.011 Get rights and content

Abstract

Purpose

Studies involving head and neck schwannomas have focused predominantly on involvement of the vestibulocochlear nerve complex (acoustic neuroma) because of the associated morbidity related to lesions involving that region. However, the majority of head and neck schwannomas are not of vestibular nerve origin and may also produce significant morbidity due to involvement of the orbit, skull base, and cranial nerves. The purpose of this study is to examine the presenting signs and symptoms, location, nerve of origin, and outcome after treatment of patients with nonvestibular schwannomas of the head and neck.

Materials and methods

The medical and pathological records of all patients with nonvestibular head and neck schwannomas treated at a single institution between 1979 and 1999 were retrospectively reviewed.

Results

Eighteen (69%) of 26 patients presented with symptoms secondary to mass effect or nerve deficit. The parapharyngeal space was the most common site of tumor origin occurring in 8 patients (31%). The nerve of origin was identified in 16 patients (62%). Twenty-three patients (88%) had complete surgical excision, and 3 patients (12%) had subtotal resection. Postoperative nerve injury occurred in 16 patients (62%) with resolution in 7 patients (44%).

Conclusions

Nonvestibular head and neck schwannomas occur most commonly in the parapharyngeal space, and presenting signs or symptoms are usually related to mass effect or neural deficit. Complete tumor removal is often achieved, but subtotal or near-total resection may be indicated for patients with extensive skull base, middle ear, or facial nerve involvement. Postoperative morbidity is associated with nerve injury from the surgical approach and/or resection of the involved nerve.

Introduction

Schwannomas (neurinoma, neuroma, or neurilemmoma) are benign encapsulated nerve sheath neoplasms of Schwann-cell derivation. Schwann cells surround peripheral nerves and schwannomas can originate from virtually any peripheral nerve with the exception of the olfactory and optic nerves. Schwannomas are usually solitary neoplasms, but multiple neurofibromas may be seen in patients with von Recklinghausen's disease. There is a reported incidence of 1 in 3000 births. Patients with these tumors generally present between 20 and 50 years of age. Males and females are equally affected, and approximately 25% to 45% of these neoplasms are found in the head and neck region [1].

Approximately 8% of head and neck schwannomas involve the intracranial portion of a peripheral nerve sheath. The vestibular nerve is most frequently involved [2]. Research efforts for head and neck schwannomas have focused predominantly on involvement of the vestibulocochlear nerve complex (acoustic neuroma) because of the associated morbidity related to lesions involving that region. However, the majority of head and neck schwannomas are of nonvestibular origin and have been reported to arise from various sites including the middle ear, mastoid cavity, sinonasal region, orbit, neck, posterior pharynx, parapharyngeal space, and skull base [3], [4], [5], [6], [7], [8], [9]. Although benign and slow growing, schwannomas of nonvestibular origin can produce significant morbidity through involvement of vital structures such as the orbit, skull base, and cranial nerves.

Studies of nonvestibular head and neck schwannomas have been infrequent and usually focus on a subsite within the head and neck. The purpose of this study is to examine the presenting signs and symptoms, location, nerve of origin, and outcome after treatment of all nonvestibular schwannomas of the head and neck over a 20-year period.

Section snippets

Materials and methods

All patients with nonvestibular head and neck schwannoma were retrospectively reviewed from the medical records and pathologic archives of the PennState Milton S Hershey Medical Center from 1979 to 1999. Information collected included patient age, sex, presenting signs and symptoms, tumor location, nerve of origin, imaging modalities, surgical approaches, and outcome after treatment.

Surgical specimens were stained by standard histologic methods. The presence of characteristic Antoni A or B

Results

Twenty-eight patients with nonvestibular head and neck schwannomas were identified. One patient with a cutaneous schwannoma and another with neurofibromatosis II were excluded from the study. The study population consisted of 10 males and 16 females with a mean age of 47 years (range, 15 to 77 years). Sixteen of the 26 patients underwent preoperative imaging with contrast-enhanced computed tomography or magnetic resonance imaging (MRI) to help delineate the extent of the neoplasms and the

Discussion

Approximately 25% to 45% of schwannomas arise in the head and neck region. These tumors occur most commonly in patients between 20 and 50 years of age, and only about 12% are seen in the pediatric or adolescent population similar to the distribution in the current study population [4]. Although the literature is replete with studies focusing on schwannomas involving the vestibular nerve complex (ie, acoustic neuromas), less data are available for nonvestibular head and neck schwannomas.

In the

Conclusion

The present study focuses on the clinical characteristics, treatment, and outcome of nonvestibular head and neck schwannomas. The majority of patients are symptomatic at the time of presentation with a neck mass being the most common presenting sign. Preoperative, peripheral nerve dysfunction is often related to the nerve of origin or adjacent nerves from tumor compression. The parapharyngeal space is the most common nonvestibular head and neck location in the study population. Complete

References (20)

P. Celli et al.
Neurinoma of the third, fourth and sixth cranial nerves: a survey and report of a new fourth nerve case
Surg. Neurol.
(1992)
M. Sheridan et al.
Cervical sympathetic schwannoma: a case report and review of the English literature
Otolaryngol. Head Neck Surg.
(1997)
Y. Kanemoto et al.
Primarily extracranial jugular foramen neurinoma manifesting with marked hemiatrophy of the tongue: case report
Surg. Neurol.
(1998)
P.M. Som et al.
Lesions of the parapharyngeal space
Otolaryngol. Clin. North Am.
(1995)
A.B. Dublin et al.
Intranasal schwannoma: magnetic resonance and computed tomography appearance
Am. J. Otolaryngol.
(1995)
D.C. Bloch et al.
The fate of the tumor remnant after less-than-complete acoustic neuroma resection
Otolaryngol. Head Neck Surg.
(2004)
B.E. Pollock et al.
Stereotactic radiosurgery: the preferred management for patients with nonvestibular schwannomas?
Int. J. Radiat. Oncol. Biol. Phys.
(2002)
J.A. Wilson et al.
Nerve-sheath tumors of the head and neck
Ear Nose Throat J.
(1988)
H. Tung et al.
Sixth nerve schwannomas
J. Neurosurg.
(1991)
K.D. Olsen
Tumors and surgery of the parapharyngeal space
Laryngoscope
(1994)

There are more references available in the full text version of this article.

Cited by (61)

Intracapsular enucleation of cervical schwannomas via retroauricular hairline incision
2022, Surgical Oncology
Citation Excerpt :
Schwannomas are a rare type of benign tumours that can arise from any peripheral sensory or motor nerve in the body [1]. Approximately 25%–45% of extracranial non-vestibular schwannomas are found in the head and neck [2,3]. Schwannomas presenting in the cervical region are commonly found in the parapharyngeal space.
Cervical schwannomas are rare diseases treated by complete resection, leading to potential neurological deficits. Intracapsular enucleation is an acceptable alternative to preserve the involved nerve function, but the clinical outcomes by an aesthetically pleasing approach remain unrevealed. This study evaluated functional and oncological outcomes after intracapsular enucleation of cervical schwannomas via retroauricular hairline (Roh's) incision.
This prospective observational study included 17 patients with cervical schwannomas who underwent intracapsular enucleation to preserve the involved nerve and capsule via Roh's incision. Each patient was evaluated with any complications, nerve function, subjective satisfaction, voice and swallowing questionnaires, and local recurrence.
Intracapsular enucleation via the Roh's incision was successfully applied to all patients for a median operation time of 48 min. Tumours of 4.5-cm median size were removed with the minimization of injury to the nerve and sheath deflected on the surface of the tumour. Temporary and permanent paralysis of the unilateral vocal fold was found in 3 (33%) and none of 9 patients with vagal schwannomas, respectively. Horner's syndrome occurred temporarily in two of 5 (40%) patients with sympathetic chain schwannomas. Postoperative complications were minor. Subjective satisfaction of scar and facial deformity was high, and subjective voice and swallowing difficulties were minimal one year after surgery. No recurrence was found in the patients for a median follow-up of 82 months.
Intracapsular enucleation via Roh's incision is a viable treatment for cervical schwannomas with the highest functional, cosmetic, and oncological outcomes.
Orbital Frontal Nerve Schwannoma—Distinctive Radiological Features
2018, American Journal of Ophthalmology
To review the radiological findings of frontal nerve schwannoma of the orbit and determine distinguishing imaging features.
Retrospective interventional case series.
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).
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.
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.
Imaging in Otolaryngology
2018, Imaging in Otolaryngology
Intramasseteric Schwanoma mimicking an isolated cheek mass: Case report and review of literature
2018, International Journal of Surgery Case Reports
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.
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.
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.
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.
Parapharyngeal Schwannoma of the Mandibular Nerve Associated With Auditory Changes
2017, Journal of Oral and Maxillofacial Surgery
Citation Excerpt :
Hearing loss presented in 5%, tinnitus in 2%, and Eustachian tube dysfunction in fewer than 1% of cases documented in a cumulative series of the signs and symptoms of parapharyngeal tumors.8 Excluding vestibular neuromas, hearing loss might be more common in middle ear with intracranial trigeminal schwannomas, with or without parapharyngeal extension, and have been seen in 8 to 10% of cases.6,9 Thus, the occurrence of gradually developing facial swelling and paresthesia, in addition to auditory symptoms, should prompt investigation for a possible parapharyngeal space tumor, including a schwannoma associated with the mandibular nerve.
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.
Diagnostic Imaging: Head and Neck
2017, Diagnostic Imaging: Head and Neck

View all citing articles on Scopus

^☆: Presented at the 5th International Head and Neck Conference, San Francisco, CA, July 2000.

¹: Dr Malone is presently with the Division of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL.

View full text

Original contributionClinical characteristics and treatment outcome for nonvestibular schwannomas of the head and neck☆

Abstract

Purpose

Materials and methods

Results

Conclusions

Introduction

Section snippets

Materials and methods

Results

Discussion

Conclusion

Surg. Neurol.

Otolaryngol. Head Neck Surg.

Surg. Neurol.

Otolaryngol. Clin. North Am.

Am. J. Otolaryngol.

Otolaryngol. Head Neck Surg.

Int. J. Radiat. Oncol. Biol. Phys.

Nerve-sheath tumors of the head and neck

Ear Nose Throat J.

Sixth nerve schwannomas

J. Neurosurg.

Tumors and surgery of the parapharyngeal space

Laryngoscope

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