J Islamabad Med Dental Coll 2020  311 

Op e n  Ac c e s s  

 Intraparotid Facial Nerve Schwannoma in a 40-Year-Old Male 
with Hearing Loss – A Case Report 

 

Nosheen Nabi1, Qudsia Ishaq1, Muhammad Tahir2, Aslam Shah3 
1Senior Lecturer, Department of Pathology, Rawal Institute of Health Sciences, Islamabad Pakistan 

2Professor, Department of Pathology, Rawal Institute of Health Sciences, Islamabad Pakistan 
3Professor & HOD, Department of Surgery, Rawal Institute of Health Sciences, Islamabad Pakistan 

 

A B S T R A C T  

Schwannoma is a benign tumor of axonal nerve sheath. Head and neck area, particularly parotid gland is an uncommon 

site for Schwannoma, however it can rarely arise from the intraparotid part of facial nerve and present as either a 

symptomless mass or facial paresis. Its diagnosis before surgical intervention is important for the conservation of parotid 

gland and facial nerve. On clinical examination and imaging studies, it can be misdiagnosed easily. FNAC is a helpful tool 

for its diagnosis. This entity should not be ignored while dealing with parotid masses. We present a case of a patient 

who came with the complaint of a parotid mass. Magnetic resonance imaging (MRI) scan suggested a parotid tumor 

which proved to be a spindle cell neoplasm on Fine Needle Aspiration Cytology (FNAC). A definite diagnosis of 

schwannoma of intraparotid facial nerve was made on histopathological examination of the excision sample. 

 

Key Words: Facial nerve, Fine needle aspiration cytology, Magnetic resonance imaging, Parotid gland, Schwannoma.

Correspondence: 
Nosheen Nabi 
Email: Nosheen.Nabi@yahoo.com 

 Article info: 
Received: October 12, 2020 
Accepted: November 11, 2020 

Cite this case Report: Nabi N, Ishaq Q, Tahir M, Shah A. Intraparotid Facial Nerve Schwannoma 
in a 40-Year-Old Male with Hearing Loss – A Case Report. J Islamabad Med Dental Coll. 2020; 
9(4): 311-314. Doi: 10.35787/jimdc.v9i4.616 
 

Funding Source: Nil 
Conflict of Interest: Nil 

I n t r o d u c t i o n  

Schwannoma is a slow growing encapsulated benign 

tumor arising from the Schwann cells of the nerve 

fiber sheath.1 Approximately 25-30% of all reported 

schwannomas occur in the head and neck region. 

Schwannoma of the facial nerve is a rare entity with 

very few cases reported in the literature.2 

Preoperative diagnoses of parotid schwannoma is 

difficult because clinically it presents as a parotid 

gland tumor and on imaging, it is indistinguishable 

from pleomorphic adenoma.3 We report a case of 

intraparotid schwannoma involving the 

extratemporal part of the facial nerve, which is 

exceedingly rare. 

C a s e  R e p o r t  

A 40-year-old male presented with a history of 

gradually increasing swelling of the left-sided 

parotid region for one and a half year (Figure 1). He 

had gradual hearing loss with on and off complaint 

of pain in the affected area. On clinical examination, 

there was a firm and immobile swelling measuring 

5x4 cm in the left parotid region. A clinical diagnosis 

C A S E  R E P O R T  



 

                      J Islamabad Med Dental Coll 2020  312 

of parotid gland tumor was made. MRI and FNAC 

was advised.  

 

Figure 1: Patient with left parotid swelling. A: Before 
surgery. B: After surgery 

MRI revealed an altered mixed signal intensity, 

heterogeneously enhancing lesion in the left parotid 

region, extending medially along posterior aspect of 

ramus of left hemi-mandible into the left 

parapharyngeal space. This was suggestive of a 

neoplastic disease process, possibly originating from 

the parotid gland. 

FNAC was performed as per standard techniques 

and the moderately cellular smears showed benign 

looking spindle cells arranged in a fascicular pattern. 

Cytology favored benign spindle cell neoplasm, most 

likely, schwannoma (Figure 2). 

 

Figure 2: Smears were moderately cellular showing 
fascicles of spindle cells. A: Giemsa stain 100x. B: H&E 
400x. 

Patient was operated for the removal of the lesion. 

The facial nerve trunk was found deeper and inferior 

due to the pushing effect of the tumor (Figure 3A). 

On anterior dissection the tumor was found to 

originate from the buccal and zygomatic branches of 

the facial nerve. The mass was removed successfully 

with careful dissection.  

On gross examination the tumor was well 

circumscribed, encapsulated, measuring 5x4 cm in 

diameter (Figure 3A). Microscopic examination 

showed an encapsulated tumor composed of 

hypercellular spindle cell areas (Antoni A) (Figure 3B) 

and hypocellular areas (Antoni B) (Figure 3C). 

Hyalinized vessels were also seen (Figure 3D). 

 

Figure 3 A: Gross specimen of the resected parotid mass. 
B: Antoni A areas showing Verocay bodies (H&E 400x). 
C: Antoni B areas showing myxoid matrix with 
entrapped macrophages (H&E 400x). D: Hyalinized 
blood vessels (H&E 400x). 

D i s c u s s i o n  

Schwannoma can arise from facial nerve anywhere 

along its course; from cerebellopontine angle to its 

terminal branches, so it can be found extra- or 

intraparotid. Majority of the facial nerve 

schwannoma are extraparotid and only 9% occur 

inside the parotid gland. Intraparotid schwannoma 



 

                      J Islamabad Med Dental Coll 2020  313 

accounts for 0.2%–1.5% of all facial nerve tumors in 

the parotid gland.4 

Intratemporal facial nerve schwannoma presents as 

a nerve dysfunction in the form of facial paresis 

while extratemporal nerve involvement presents as 

a parotid mass without nerve dysfunction.5 

There are no definite radiological findings of 

intraparotid schwannoma.6 MRI is the radiological 

test of choice for detecting facial nerve 

schwannoma. The most common signs are a mass 

with signal intensity isointense to muscle on T1 and 

hyperintense to muscle on T2 sequence, 

respectively. The target sign (central low and 

peripheral higher signal intensity on T2 weighted 

images) is a sign of tumor of nerve sheath which 

includes schwannoma or malignant nerve sheath 

tumor.7 

As MRI cannot differentiate between benign or 

malignant neoplastic process FNAC is regarded as a 

useful procedure for the diagnosis. FNAC of 

schwannoma reveals moderately cellular smears 

comprising of clusters of spindle cells in a 

background composed of pink fibrillary matrix. The 

individual neoplastic cells have spindle cell wavy 

hyperchromatic nuclei with scant cytoplasm. No foci 

of necrosis or mitosis are seen.8 

Microscopically, Schwannoma has a specific pattern 

of hypercellular Antoni A and Antoni B areas.  

Verocay bodies are seen in Antoni A areas showing 

palisaded neoplastic cells and this is a diagnostic sign 

of schwannoma. Antoni B is composed of 

degenerative myxoid stroma and may contain 

macrophages. Presence of hyalinized blood vessels 

is also a constant feature of schwannoma.9,10 

Intraparotid facial nerve schwannomas are classified 

into four types by Marchioni et al. for better 

evaluation and management. Type A tumors include 

those neoplasms which can be operated with 

conservation of the facial nerve. Tumors in this type 

do not cause facial paresis preoperatively. In type B 

tumors, the tumor is resectable with removal of 

some part of the nerve, which is usually peripheral 

branch or distal division. The resected part is 

reconstructed by neurorrhaphy or nerve graft. In 

type C tumors, the main trunk of the facial nerve is 

resected while in type D, the main trunk and at least 

one of the temporofacial or cervicofacial branches is 

also removed.11 

The goal of the treatment is to remove the tumor 

with preservation of the facial nerve but frequently 

it is not possible to preserve the nerve. The 

management of intraparotid schwannoma depends 

on extent of facial nerve dysfunction, localization of 

tumor to parotid gland and Intratemporal extension. 

These include conservative approaches like 

extracapsular dissection and partial lateral 

parotidectomy, and more extensive interventions 

like lateral parotid lobectomy and total 

parotidectomy, respectively.12 

C o n c l u s i o n  

Preoperative diagnosis of intraparotid schwannoma 

is difficult because of its rarity and nonspecific 

radiological findings. This entity should be 

considered in the differential diagnosis of any 

parotid mass to avoid any unnecessary extensive 

surgery. We advocate the use of FNAC as a useful 

technique for the preoperative diagnosis of 

intraparotid schwannoma. 

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