Atypical tumors of the facial nerve: case series and review of the literature

Free access

Object

The authors present a series of 4 patients with rare facial nerve tumors. The relevant literature is reviewed and is discussed regarding diagnostic features, the role of operative management, and surgical approach.

Methods

A retrospective chart review was conducted for patients with tumors of the facial nerve that were treated between 2008 and 2011. Patients undergoing observation with serial MRI and those who were treated with up-front radiosurgery and for whom tissue diagnosis was not available were excluded. In addition, patients with suspected vestibular schwannoma, facial nerve schwannoma, neurofibromatosis Type 2, and metastatic disease were also excluded. The charts of 4 patients (2 men and 2 women) with “atypical” tumors were reviewed and analyzed.

Results

A total of 12 patients with tumors of the facial nerve were identified during the study period. Patient characteristics, preoperative imaging, operative approach, tumor histology, and outcomes are described.

Conclusions

Atypical facial nerve tumors must be distinguished from the more common facial nerve schwannoma. How the authors of this study treat rare facial nerve tumors is based on their experience with the more common facial nerve schwannomas, characterized by a slow progression of symptoms and growth. Less is known about the rare lesions, and thus a conservative approach may be warranted. Open questions include the role of radiosurgery, facial nerve decompression, and indications for resection of tumor and cable grafting for these rare lesions.

Abbreviations used in this paper:CPA = cerebellopontine angle; IAC = internal auditory canal.

Object

The authors present a series of 4 patients with rare facial nerve tumors. The relevant literature is reviewed and is discussed regarding diagnostic features, the role of operative management, and surgical approach.

Methods

A retrospective chart review was conducted for patients with tumors of the facial nerve that were treated between 2008 and 2011. Patients undergoing observation with serial MRI and those who were treated with up-front radiosurgery and for whom tissue diagnosis was not available were excluded. In addition, patients with suspected vestibular schwannoma, facial nerve schwannoma, neurofibromatosis Type 2, and metastatic disease were also excluded. The charts of 4 patients (2 men and 2 women) with “atypical” tumors were reviewed and analyzed.

Results

A total of 12 patients with tumors of the facial nerve were identified during the study period. Patient characteristics, preoperative imaging, operative approach, tumor histology, and outcomes are described.

Conclusions

Atypical facial nerve tumors must be distinguished from the more common facial nerve schwannoma. How the authors of this study treat rare facial nerve tumors is based on their experience with the more common facial nerve schwannomas, characterized by a slow progression of symptoms and growth. Less is known about the rare lesions, and thus a conservative approach may be warranted. Open questions include the role of radiosurgery, facial nerve decompression, and indications for resection of tumor and cable grafting for these rare lesions.

Primary tumors of the facial nerve are uncommon lesions. Facial nerve schwannomas of the CPA and/or IAC are the most often encountered facial nerve tumors and may be mistaken for vestibular schwannomas. We present a series of 4 patients with “atypical” tumors of the facial nerve based on 1) location (not involving the CPA or IAC) and/or 2) unusual histological findings. Although individually very rare, these atypical tumors in aggregate contribute significantly to pathology of the facial nerve. The goal of the present study is to highlight the diversity of conditions affecting the facial nerve with a review of the relevant literature and discussion of nuances in diagnostic features. The role of operative management and surgical approach will also be discussed.

Methods

Retrospective Chart Review

The charts of all patients with tumors of the facial nerve treated between 2008 and 2011 by the senior author (G.P.L.) were retrospectively reviewed. Patients undergoing observation with serial MRI and those who were treated with upfront radiosurgery and for whom tissue diagnosis was not available were excluded. In addition, patients with suspected vestibular schwannoma, facial nerve schwannoma, neurofibromatosis Type 2, and metastatic disease were also excluded. Preoperative and postoperative imaging studies including CT scanning of the temporal bone and MRI were reviewed by an independent neuroradiologist. Facial nerve outcomes were evaluated based on House-Brackmann grade at presentation and at last follow-up (Table 1).

TABLE 1:

Patient characteristics and surgical diagnosis in the 4 patients illustrated in this paper

Case No.Preop House-Brackmann GradeTime From Onset of SymptomsSurgical Pathology
1III2 mosparaganglioma
2VI10 mosschwannoma
3I1 yrmeningioma
4I–II5 yrshemangioma

Literature Review

A systematic search was performed using the PubMed and MEDLINE databases to identify case series involving facial nerve hemangiomas, facial nerve meningiomas, and facial nerve glomus tumors (Table 2). Initial key words included “facial nerve hemangioma” and “intratemporal hemangioma,” which yielded 218 results. After systematic review, we were able to locate 9 complete articles with case reports in the English-language literature. When searching for case reports discussing facial nerve meningiomas, we used the key words “facial nerve meningioma.” This yielded 33 results, of which 7 were complete articles. Finally, “facial nerve glomus tumor” and “paraganglioma facial nerve” were the key words used to locate case reports of glomus facialis tumors. There were 156 resulting articles, most of which described the more common glomus jugulare. Our search yielded a total of 9 case reports in the literature to date. We excluded all case reports that refrained from disclosing details related to presentation, diagnostics, and management, leaving 7 articles for review.

TABLE 2:

Summary of pre- and postoperative characteristics of patients with atypical facial nerve tumors in the literature*

Authors & YearNo. of PatientsTumor TypeAge in Yrs, SexSymptomsDiagnosticsTreatment ApproachChange in House-Brackmann Grade or Outcome
Gavilán et al., 19901hemangioma38, MFP, HLCT, MRI, audiometryTM0
Balkany et al., 19911hemangioma24, MFPENoG, ABR, audiometry, HRCTTM+3
Friedman et al., 20022hemangioma51, M; 55, FFP (50%), HFS (100%), HL (50%), vertigo (50%), tinnitus (50%)HRCT, MRI, audiometry, ENoGTM + MF, GAN graft0 (100%)
Fierek et al., 20041hemangioma6, MHLHRCT, MRITMNA
Miyashita et al., 20071hemangioma47, MFPaudiometry, stapedial reflex, HRCT, MRIMF, GAN graft+1
Benoit et al., 20107hemangiomarange 38–55FP (100%), vertigo (14%), HFS (14%), HL (29%)ENoGMF (100%)+3 (17%), +2 (67%), 0 (17%), −1 (17%)
Ahmadi et al., 20121hemangioma53, MFP, HFSMRI, HRCT, audiometry, EMGTM, GAN graft−1
Mijangos et al., 20111hemangioma50, MFPHRCT, MRINANA
Falcioni et al., 20032818 schwannoma, 6 hemangioma, 2 meningioma, 2 neurofibromamean 40.3 (18 M, 10 F)FP (82%), HL (46%), tinnitus (18%), HFS (14%)MRI, HRCTMF (25%), MF + TM (21%), TM (14%), TL (18%), cable graft (86%)NA
Jabor et al., 20001meningioma7, FFP (100%), vertigo (14%), FT (14%), HL (29%)MRI, CT, audiographycombined MF/TM w/ SN graftHL, partial motor recovery
Chung et al., 19971meningioma16, FFPHRCTMF+1
Magliulo et al., 20101meningioma45, FFP, HLHRCT, MRI, audiometryMF + TM, GAN graft+2
Larson et al., 19952meningioma19 & 23, FFP (100%)HRCT, MRI, audiometryMF (100%), GAN graft (50%)unknown
Luetje et al., 19976meningiomarange 5–40 (1 M, 5 F)FP (100%), vertigo (17%), HL (33%)HRCT, MRIMF (33%), MF/TM (67%), SN graft (33%), GAN graft (50%)+2 (33%), +1 (33%), 0 (16%), −2 (16%)
Collin et al., 20121meningioma48, FFPMRI, HRCT, audiometryMF/GAN graftunknown
Dutcher & Brackmann, 19861glomus50, FFPCTTMunknown
Bartels et al., 19902glomus20 & 40, MFP (50%), tinnitus (50%), HL (50%)CTunavailableNA
Petrus & Lo, 19962glomus74, FFP (50%), tinnitus (50%)HRCTTM, radiotherapyunknown
Kania et al., 19991glomus63, FFP, tinnitus, otalgiaHRCT, audiometryTM, SN+2
Mafee et al., 20001glomus37, FFP, otalgiaunknownresectionunknown
Connor et al., 20081glomus54, FFP, otalgiaHRCTresectionunknown
Kunzel et al., 20121glomus39, MFPHRCT, MRITM, GAN graft+3

* ABR = auditory brainstem response testing; EMG = electromyography; ENoG = electroneuronography; FP = facial paresis; FT = facial twitching; GAN = greater auricular nerve; HFS = hemifacial spasm; HL = hearing loss; HRCT = high-resolution CT; MF = middle fossa; NA = not available; SN = sural nerve; TL = translabyrinthine; TM = transmastoid.

† Percentages represent the percentage of patients.

Results

A total of 12 patients with tumors of the facial nerve were identified during the study period. Preoperatively identified facial nerve schwannomas treated with up-front radiosurgery (n = 2) or with resection and cable grafting (n = 2) were excluded from analysis. In addition, a facial nerve schwannoma diagnosed intraoperatively during surgery as a presumed vestibular schwannoma (n = 1) and a metastatic tumor to the CPA (n = 1) causing facial weakness were excluded from analysis. Finally, tumors that were believed to be facial nerve schwannomas based on imaging and that had been managed with a “wait and scan” approach were similarly excluded (n = 2). One tumor that was isolated to the mastoid segment of the facial nerve and that exhibited radiographic features believed to be unusual for schwannoma was found at surgery to be a schwannoma; this case was included because the tumor was not identified preoperatively as a facial nerve schwannoma (see Case 2 below). The charts of the 4 patients with “atypical” tumors of the facial nerve were reviewed and analyzed.

Patient Characteristics

There were 2 men and 2 women. The mean age was 53 years old. All 4 patients presented with some degree of facial paresis, except the patient in Case 3; the length of time from onset of facial weakness to diagnosis was 21 months. Three of the 4 patients had a history of remote Bell palsy, after which a complete recovery was made.

Surgical interventions included facial nerve decompression (n = 3), partial tumor resection and/or biopsy (n = 3), and tumor resection with interposition cable graft (n = 1). The approach was via a middle fossa craniotomy (n = 2) or a transpetrosal one (n = 2). Tumor histology was consistent with a hemangioma of the facial nerve (n = 1), meningioma (n = 1), schwannoma (n = 1), and a glomus facialis tumor (n = 1).

The mean preoperative House-Brackmann facial nerve grade was III. The mean House-Brackmann facial nerve grade at last follow-up was II. There was no major perioperative morbidity or death.

Illustrative Cases

Case 1

This 52-year-old woman presented with a 2-month history of right facial weakness. She developed Bell palsy on the right side more than 10 years previously, which had resolved within a few days with steroids and antiviral medication. This time, however, she did not respond to steroids. For this reason, MRI and CT scanning of the temporal bone were performed. These studies showed a right 10 × 12–mm skull base lesion situated within the right mastoid with some degree of contrast enhancement consistent with a neoplasm (Fig. 1). Differential considerations included glomus tumor and schwannoma. On examination, the patient was intact except for facial weakness (House-Brackmann Grade III). The patient underwent a right transtemporal craniotomy including mastoidectomy and decompression of the sigmoid sinus with microsurgical resection of the extradural skull base paraganglioma and decompression of the vertical segment of the facial nerve from the facial recess to the stylomastoid foramen. Surgical pathology was compatible with paraganglioma. The patient had worsening facial paresis postoperatively (House-Brackmann Grade VI) that at last follow-up (13 months) improved back to the preoperative level (House-Brackmann Grade III); there has been no progression of residual tumor.

Fig. 1.
Fig. 1.

Preoperative axial precontrast (A), postcontrast T1-weighted (B), and T2-weighted (C) MR images revealing a right 10 × 12–mm skull base lesion situated within the right mastoid.

Case 2

This 77-year-old man presented with left facial weakness that progressed over a period of 9 months. Magnetic resonance imaging with and without contrast showed a left temporal tumor, which involved the vertical segment of the facial nerve (Fig. 2). The CT scan showed an expansive lytic process involving the left facial nerve region. Differential diagnosis included neoplastic processes arising from the facial nerve or from the jugular fossa involving the facial nerve. On examination, he was intact except for severe facial weakness (House-Brackmann Grade VI). The patient underwent the following procedures: postauricular intratemporal craniotomy with microsurgical resection of the facial nerve schwannoma, interposition graft of the facial nerve with a collagen tubule and 15-cm harvest of the sural nerve, parotidectomy, and tympanoplasty with ossicular reconstruction. The surgical specimen was compatible with a schwannoma (WHO Grade I). At last follow-up (12 months), the patient had no significant improvement in facial nerve function and was referred for a facial sling procedure.

Fig. 2.
Fig. 2.

Preoperative axial precontrast (A) and postcontrast T1-weighted (B and C) MR images revealing a left temporal tumor, which involves the vertical segment of the facial nerve.

Case 3

This 49-year-old man presented with right ear fullness lasting 1 year and 1 episode of dizziness 2 years prior (from which he had a full recovery). Magnetic resonance imaging and CT temporal bone studies showed a right enhancing temporal bone mass and enlargement of the facial nerve along the geniculate ganglion, most consistent with hemangioma followed by facial nerve schwannoma and meningioma (Fig. 3). On physical examination, the patient was intact. The patient underwent a combined transmastoid and middle fossa craniotomy with resection of extradural skull base tumor and tegmen reconstruction. Surgical pathology was compatible with meningioma (WHO Grade I). Although he continued to have some right ear pressure, the patient's otological examination revealed normal findings.

Fig. 3.
Fig. 3.

Preoperative temporal bone CT scan (A) and axial precontrast (B), postcontrast T1-weighted (C), and T2-weighted (D) MR images demonstrating a right enhancing temporal bone mass and enlargement of the facial nerve along the geniculate ganglion.

Case 4

This 37-year-old woman presented with a 5-year history of vertigo. Three years later she developed Bell palsy. Since then, she has complained of left facial weakness and synkinesis and received Botox injections in January 2010. Despite this treatment, she continued to have facial weakness. Findings from initial imaging, including MRI performed 5 years earlier, were thought to be negative. Subsequent imaging demonstrated slight irregular enhancement of the labyrinth and geniculate segment of the facial nerve. Her CT scanning examination showed an ossified lytic spiculated lesion in the area of the geniculate segment of the facial nerve (Fig. 4). On physical examination, the patient was intact except for mild left facial asymmetry and House-Brackmann Grade I–II left facial weakness. Differential diagnosis included an inflammatory process versus a benign neoplasm such as facial nerve schwannoma or hemangioma. The patient underwent a left middle fossa craniotomy for resection of the tumor and facial nerve decompression. Surgical pathology was compatible with hemangioma. Postoperatively, she did well and her face was symmetric (House-Brackmann Grade I).

Fig. 4.
Fig. 4.

Preoperative axial postcontrast T1-weighted MR image (A) and axial CT images (B and C) showing a spiculated lesion in the area of the geniculate segment of the facial nerve.

Discussion

We present a series of rare facial nerve tumors with features atypical from those seen in the more common facial nerve schwannoma, which in autopsy series may have an incidence as high as 0.8%.36 Facial nerve schwannomas typically involve the geniculate ganglion, IAC, and CPA (Fig. 5). Facial nerve schwannomas, such as the case included here, entirely confined to the temporal bone are exceedingly rare.

Fig. 5.
Fig. 5.

Atypical facial nerve tumor illustration. Diagram by Lindsey Ross and Brian Nicholas. Printed with permission from Lindsey Ross, M.D.

Facial nerve hemangiomas were first described by Politzer in 1901.25 Again, this lesion has a predilection for the geniculate ganglion. Once thought to occur here as result of pertinent anastomosis, it has recently been found to arise as a consequence of its dense capillary but anatomically distinct network. When compared with the neighboring segments of the geniculate ganlgion (that is, the tympanic and labyrinthine segments), there are upward of 46 cases reported in the literature of facial nerve hemangioma involving the geniculate ganglion.2 Hemangiomas are also commonly known as benign vascular tumors. There is evidence to prove that facial nerve hemangiomas should be correctly categorized as venous malformations, given the lack of internal elastic laminae noted on histological examination.1,4 In fact, Benoit et al.4 attempted to reclassify facial nerve hemangiomas using histological and immunohistochemical markers in the context of commonly accepted vascular lesion nomenclature. The distinction is understood when the true definition is studied. Benign vascular tumors arise directly from cellular hyperplasia, whereas malformations arise from errors in vascular morphogenesis.4

Facial nerve hemangiomas usually present in midlife, specifically between the 3rd and 6th decades. There appears to be an equal distribution of males and females. Approximately 97% of patients with atypical facial nerve tumors present with some degree of facial nerve deficit.14 Quite often, there is a spectrum of motor deficit that varies from hemifacial spasms to facial paresis. Hearing loss is also common and may be characterized as conductive if the horizontal segment of the facial nerve is involved or sensorineural if the tumor affects the labyrinthine segment or geniculate ganglion. Again, ipsilateral hearing loss is the most prevalent presenting symptom. Nonetheless, the deficit often is slow in progression or renders a recurrent episodic course, which allows us to make the distinction between other facial nerve tumors. Patients are often misdiagnosed and treated for idiopathic facial nerve weakness (Bell palsy), a much more common etiology of facial nerve paresis. The temporal characteristic of facial paralysis is of utmost importance in diagnoses. With Bell palsy, 85% of patients experience recovery of facial paresis to House-Brackmann Grade I or II in approximately 8–12 weeks, whereas patients with atypical facial nerve tumors, such as facial nerve hemangiomas, often experience a more indolent course without recovery of facial motor function. Uniquely, facial nerve hemangioma size is not directly correlated to the extent of deficit. Small tumors (< 10 mm) may lend themselves to grave deficits. There is debate in the literature with respect to the etiology of the neurological deficit. Previous reports in the literature have claimed that facial nerve deficits arise as a consequence of direct compressive forces; newer schools of thought believe that there is an element of a vascular steal phenomenon wherein blood flow to the highly vascular facial nerve is detoured toward the tumor, resulting in ischemic insult.4,35 For this reason, facial nerve schwannomas of similar size may lead to less severe cranial nerve dysfunction.26

The relationship between facial nerve hemangioma and cavernous malformations isolated to the seventh cranial nerve is controversial. Deshmukh et al.8 described 2 patients who presented with acute hearing loss and facial nerve paresis; MRI revealed hyperintense lesions, without contrast enhancement, which were found to have small cavernous malformations. Importantly, extraaxial cavernous malformations may also enhance following the administration of Gd, so the presence of enhancement is not sufficient to rule out the presence of a cavernous malformation. The incidence of these lesions is too low to determine whether these lesions are truly distinct from facial nerve hemangioma, or merely histological variations of the same clinicopathological entity.

Although meningiomas are the second most common tumor of the CPA, geniculate meningiomas are exceedingly rare.27 Although the etiology is unclear, noted associations with progesterone, breast cancer, and radiation therapy have been described.17 Meningiomas arise from arachnoid villi, which are invaginations of the arachnoid mater along the walls of the dural and venous sinuses. They are also located along the neural foramina of the cranial nerves. Facial nerve meningiomas most likely arise from the arachnoid villi along the porus acousticus (opening between the CPA cistern and IAC) and gasserian envelope. This can be explained embryonically. The seventh and eighth cranial nerves arise from a common primordium. At 5 weeks of gestation, the fibers of the facial nerve exit the neural tube along with a sheath of arachnoid and dura. Although the dura terminates at the IAC, the arachnoid may continue toward the geniculate ganglion and beyond as it gradually fuses with endoneurium.19,31 Extracranial extension of a neural foramen meningioma is quite rare. More commonly, the tumor would originate intracranially and extend extracranially.

Glomus tumors are also known as paragangliomas or chemodectomas that arise from chemoreceptor cell derivatives of neural crest cells. They originate from paraganglionic tissue typically at the carotid bifurcation (carotid body tumors), jugular foramen (glomus jugulare), vagus nerve (glomus vagale), and tympanic plexus (glomus tympanicum).21 They may occur sporadically or as a part of hereditary syndromes such as multiple endocrine neoplasia Type II (MEN II), von Hippel-Lindau syndrome, and neurofibromatosis Type 1.21 In 80% of hereditary cases and 20% of sporadic cases, the patient presents with multiple lesions.

A landmark histological study by Guild in 1941 described 73 temporal bone paragangliomas.32 The thought is that the glomus tumor may arise from the Arnold nerve, an auricular branch of the vagus nerve that traverses through the mastoid canaliculi from the jugular bulb, superior to the fallopian canal at the stylomastoid foramen, where an ascending branch merges with the facial nerve. This is the same nerve that gives rise to glomus jugulare and glomus tympanicum.9

Preoperative Evaluation

Any patient with a suspected tumor of the facial nerve should be evaluated with high-resolution CT scanning of the temporal bone, MRI with and without contrast, and direct otoscopic examination. Large tumors involving the tympanic segment of the facial nerve may be visible on otoscopic examination. Gross features such as vascularity may aid in diagnosis, and transcanal biopsy may be performed in select cases. Electroneurography may also be of assistance in select cases.

Careful review of preoperative radiographs may help to establish the diagnosis of facial nerve schwannoma, especially in the presence of geniculate ganglion enhancement, anterior position of the tumor in the IAC, or linear enhancement of the facial nerve in the mastoid temporal bone.38 Schwannomas will typically create a smooth but enlarged course along the fallopian canal and may be differentiated from hemangiomas, which lack distinct margins and often contain bony spicules on thin-cut CT. They will also enhance on postcontrast T1-weighted MRI.

Facial nerve hemangiomas are best visualized via high-resolution CT scanning of the temporal bone, namely enlargement of the fallopian canal with a lesion exhibiting irregular margins, amorphous shape, and possibly intratumoral bony spicules. The typical honeycomb or sunburst radiographic appearance is indicative of an ossifying hemangioma. This occurs as a result of osteoclastic remodeling resulting in intralesional lamellar bony trabeculae.4,29 The honeycomb sign is pathognomonic for hemangioma and helps to differentiate between schwannoma and meningioma. Nevertheless, this is present only 50% of the time.11 This is also known as an ossifying hemangioma.29 Magnetic resonance imaging of the brain, with thin-cut sequences through the temporal bone at the IAC, is used if the lesion is not visualized. One would expect to see iso-, hyper-, or variable intensity on T1-weighted images and hyperintensity on T2-weighted images as well as enhancement with Gd contrast. Of note, one would expect normal variations of mild to moderate enhancement of certain aforementioned highly vascularized segments of the facial nerve, namely the geniculate ganglion and tympanic and labyrinthine segments.

Circumferential expansion of the facial nerve canal with well-preserved margins and smooth architecture are typical findings in cases of glomus facialis and are findings comparable to characteristics of schwannoma on CT scanning. Magnetic resonance imaging of the temporal bone, when performed, may reveal a pathognomonic salt-and-pepper pattern as described by Olsen et al.33 in paragangliomas larger than 2 cm. Otherwise, the lesion has been noted to show hypointensity to muscle on T1-weighted imaging and heterogeneous enhancement with Gd contrast injection. On T2-weighted imaging, there is isointensity to muscle.18 Angiographic findings include hypervascularity, an enlarged feeding artery, and possible draining vein. This often assists in diagnosis, as rapid arteriovenous shunting is not seen in hemangiomas.

Management

Due to their rarity, there is little guidance in the literature for the appropriate management of facial nerve tumors. Recommendations may be reasonably extrapolated from the approach to the more common facial nerve schwannoma. Many authors, including Shirazi et al.,37 have advocated conservative treatment of facial neuromas when patients present without facial motor and hearing deficits.20,28 Treatment strategies include radiological observation, drainage of any cystic component of the tumor for histological diagnosis, and/or bony decompression of the tumor.37 Even decompression may lend itself to a delayed management approach in attempts at preserving residual nerve function. Nevertheless, if the lesion is symptomatic, resection with attempts at anatomical continuity is the gold standard. Surgical approaches include the most commonly used translabyrinthine approach, as well as the retrosigmoid approach, transmastoid or middle fossa approach, combined middle fossa–transmastoid approach, and transmastoid–transparotid approach. This is often performed with a cable nerve graft interposition of either the sural or greater auricular nerve. Falcioni et al.12 stated that the chances of satisfactory facial nerve recovery decreases significantly postoperatively if resection is not performed within the 1st year of initial clinical facial nerve dysfunction.

Hemangiomas of the facial nerve at the geniculate ganglion are best approached through the middle fossa. If the vertical segment of the facial nerve is involved and hearing is preserved, a transmastoid approach appears to obtain the best visualization. Often a combined approach is appropriate. Upon dissection a soft, dark red, or even blue, easily dissectible mass will be encountered. As a consequence, the facial nerve is often salvageable. Surgery should be offered within the 1st year of diagnosis, prior to perineural fibrosis, or actual neural infiltration develops, making resection more difficult.1 Facial nerve decompression and removal of any compressive bony spicules may prolong facial function and minimize the chances of postoperative worsening of facial paresis. Aggressive resection will likely exacerbate preexisting facial paresis and is warranted only in cases of high-grade facial nerve dysfunction (House-Brackmann Grade V or VI).

If resection is appropriate, cable grafting such as with a greater auricular nerve graft may be used. This intervention may preserve facial nerve function in the range of 50%–75%.10

Role of Radiosurgery

Recently, our group has published on the changing paradigm for treatment of facial nerve schwannoma, with an increased reliance on radiosurgery for the treatment of these tumors.39 This is often performed on the basis of MRI and CT imaging alone (that is, without tissue diagnosis). While radiosurgery has had generally favorable results for the treatment of facial nerve schwannoma, the role of radiosurgery in these atypical tumors, especially facial nerve hemangiomas, is less clear.

Other rare causes of facial nerve paresis from tumor involvement of the intratemporal facial nerve include epidermoid (cholesteatoma), metastasis, and direct invasion from skull base carcinoma. The facial nerve perineurium serves as a gateway to the temporal bone for neoplasms such as parotid mucoepidermoid carcinoma, benign pleomorphic adenoma of the parotid gland, and squamous cell carcinoma.16 Tumors extrinsic to the intratemporal segment including primary temporal bone tumors, pontine gliomas, and parotid tumors may also affect facial nerve function.

Conclusions

Much of how we approach facial nerve tumors arises from experience with the natural history of facial nerve schwannomas, characterized by indolent symptomatic progression and slow growth. However, less is known about the natural history of these atypical lesions. In the absence of sufficient clinical data to prove otherwise, a conservative approach may be warranted. Open questions include the role of radiosurgery, facial nerve decompression, and indications for resection of tumor and cable grafting for these rare lesions.

Disclosure

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author contributions to the study and manuscript preparation include the following. Conception and design: Lekovic, Drazin. Acquisition of data: Ross, Eboli. Analysis and interpretation of data: Drazin, Ross, Eboli. Drafting the article: Drazin, Ross, Eboli. Critically revising the article: Lekovic, Drazin, Ross. Reviewed submitted version of manuscript: Lekovic, Drazin, Ross. Approved the final version of the manuscript on behalf of all authors: Drazin. Study supervision: Lekovic.

References

  • 1

    Ahmadi NNewkirk KKim HJ: Facial nerve hemangioma: a rare case involving the vertical segment. Laryngoscope [epub ahead of print]2012

    • Search Google Scholar
    • Export Citation
  • 2

    Balkany TFradis MJafek BWRucker NC: Hemangioma of the facial nerve: role of the geniculate capillary plexus. Skull Base Surg 1:59631991

    • Search Google Scholar
    • Export Citation
  • 3

    Bartels LJPennington JKamerer DBBrowarsky I: Primary fallopian canal glomus tumors. Otolaryngol Head Neck Surg 102:1011051990

    • Search Google Scholar
    • Export Citation
  • 4

    Benoit MMNorth PEMcKenna MJMihm MCJohnson MMCunningham MJ: Facial nerve hemangiomas: vascular tumors or malformations?. Otolaryngol Head Neck Surg 142:1081142010

    • Search Google Scholar
    • Export Citation
  • 5

    Chung CJMukherji SFordham LBoydston WHudgins R: Geniculate ganglion meningioma. Pediatr Radiol 27:8478491997

  • 6

    Collin MBernardeschi DCazals-Hatem DSterkers O: Meningioma of geniculate ganglion: case report and review of the literature. Acta Otalaryngol [epub ahead of print]2012

    • Search Google Scholar
    • Export Citation
  • 7

    Connor SEGleeson MJOdell E: Extracranial glomus faciale tumour. J Laryngol Otol 122:9869892008

  • 8

    Deshmukh VRAlbuquerque FCZabramski JMSpetzler RF: Surgical management of cavernous malformations involving the cranial nerves. Neurosurgery 53:3523572003

    • Search Google Scholar
    • Export Citation
  • 9

    Dutcher PO JrBrackmann DE: Glomus tumor of the facial canal. A case report. Arch Otolaryngol Head Neck Surg 112:9869871986

  • 10

    Eby TLFisch UMakek MS: Facial nerve management in temporal bone hemangiomas. Am J Otol 13:2232321992

  • 11

    Escada PCapucho CSilva JMRuah CBVital JPPenha RS: Cavernous haemangioma of the facial nerve. J Laryngol Otol 111:8588611997

    • Search Google Scholar
    • Export Citation
  • 12

    Falcioni MRusso ATaibah ASanna M: Facial nerve tumors. Otol Neurotol 24:9429472003

  • 13

    Fierek OLaskawi RKunze E: Large intraosseous hemangioma of the temporal bone in a child. Ann Otol Rhinol Laryngol 113:3943982004

    • Search Google Scholar
    • Export Citation
  • 14

    Friedman ONeff BAWillcox TOKenyon LCSataloff RT: Temporal bone hemangiomas involving the facial nerve. Otol Neurotol 23:7607662002

    • Search Google Scholar
    • Export Citation
  • 15

    Gavilán JNistal MGavilán CCalvo M: Ossifying hemangioma of the temporal bone. Arch Otolaryngol Head Neck Surg 116:9659671990

    • Search Google Scholar
    • Export Citation
  • 16

    Gross BCCarlson MLMoore EJDriscoll CLOlsen KD: The intraparotid facial nerve schwannoma: a diagnostic and management conundrum. Am J Otolaryngol 33:4975042012

    • Search Google Scholar
    • Export Citation
  • 17

    Jabor MAAmedee RGGianoli GJ: Primary meningioma of the fallopian canal. South Med J 93:7177202000

  • 18

    Kania REBouccara DColombani JMMolas GSterkers O: Primary facial canal paraganglioma. Am J Otolaryngol 20:3183221999

  • 19

    Kettel K: Peripheral facial palsies due to tumors; pathology and clinical picture: a review of the literature and a report of three cases of intratemporal tumors of the facial nerve. AMA Arch Otolaryngol 69:2762921959

    • Search Google Scholar
    • Export Citation
  • 20

    Kim CSChang SOOh SHAhn SHHwang CHLee HJ: Management of intratemporal facial nerve schwannoma. Otol Neurotol 24:3123162003

    • Search Google Scholar
    • Export Citation
  • 21

    Kunzel JZenk JKoch MHornung JIro H: Paraganglioma of the facial nerve, a rare differential diagnosis for facial nerve paralysis: case report and review of the literature. Eur Arch Otorhinolaryngol 269:6936982012

    • Search Google Scholar
    • Export Citation
  • 22

    Larson TLTalbot JMWong ML: Geniculate ganglion meningiomas: CT and MR appearances. AJNR Am J Neuroradiol 16:114411461995

  • 23

    Luetje CMSyms CA IIILuxford WEStorper ISGlasscock ME IIIBrackmann DE: Meningiomas intrinsic to the geniculate ganglion. Am J Otol 18:3933971997

    • Search Google Scholar
    • Export Citation
  • 24

    Mafee MFRaofi BKimar AMuscato C: Glomus faciale, glomus jugulare, glomus tympanicum, glomus vagale carotid body tumors, and stimulating lesions. Role of MR imaging. Radiol North Am 38:105910762000

    • Search Google Scholar
    • Export Citation
  • 25

    Magliulo GAlla FRColicchio GTrasimeni G: Geniculate ganglion meningioma. Skull Base 20:1851882010

  • 26

    Mangham CACarberry JNBrackmann DE: Management of intratemporal vascular tumors. Laryngoscope 91:8678761981

  • 27

    Maniglia AJ: Intra and extracranial meningiomas involving the temporal bone. Laryngoscope 88:9 Pt 2 Suppl 121581978

  • 28

    McMonagle BAl-Sanosi ACroxson GFagan P: Facial schwannoma: results of a large case series and review. J Laryngol Otol 122:113911502008

    • Search Google Scholar
    • Export Citation
  • 29

    Mijangos SVMeltzer DE: Case 171: facial nerve hemangioma. Radiology 260:2963012011

  • 30

    Miyashita THoshikawa HKagawa MMori N: A case report of facial nerve hemangioma. Auris Nasus Larynx 34:5195222007

  • 31

    Nager GT: Meningioma involving the temporal bone: clinical and pathological aspects. Ir J Med Sci 41:69961966

  • 32

    O'Leary MShelton CGiddings NKwartler JBrackmann DE: Glomus tympanicum tumors: a clinical perspective. Laryngoscope 101:103810431991

    • Search Google Scholar
    • Export Citation
  • 33

    Olsen WLDillon WPKelly WMNorman DBrant-Zawadzki MNewton TH: MR imaging of paragangliomas. AJR Am J Roentgenol 148:2012041987

    • Search Google Scholar
    • Export Citation
  • 34

    Petrus LVLo WM: Primary paraganglioma of the facial nerve canal. AJNR Am J Neuroradiol 17:1711741996

  • 35

    Semaan MTSlattery WHBrackmann DE: Geniculate ganglion hemangiomas: clinical results and long-term follow-up. Otol Neurotol 31:6656702010

    • Search Google Scholar
    • Export Citation
  • 36

    Sherman JDDagnew EPensak MLvan Loveren HRTew JM Jr: Facial nerve neuromas: report of 10 cases and review of the literature. Neurosurgery 50:4504562002

    • Search Google Scholar
    • Export Citation
  • 37

    Shirazi MALeonetti JPMarzo SJAnderson DE: Surgical management of facial neuromas: lessons learned. Otol Neurotol 28:9589632007

    • Search Google Scholar
    • Export Citation
  • 38

    Wiggins RH IIIHarnsberger HRSalzman KLShelton CKertesz TRGlastonbury CM: The many faces of facial nerve schwannoma. AJNR Am J Neuroradiol 27:6946992006

    • Search Google Scholar
    • Export Citation
  • 39

    Wilkinson EPHoa MSlattery WH IIIFayad JNFriedman RASchwartz MS: Evolution in the management of facial nerve schwannoma. Laryngoscope 121:206520742011

    • Search Google Scholar
    • Export Citation

If the inline PDF is not rendering correctly, you can download the PDF file here.

Article Information

Address correspondence to: Gregory P. Lekovic, M.D., Ph.D., House Research Institute, House Clinic Neurosurgical Associates, 2100 West Third Street, Los Angeles, California 90057. email: glekovic@hei.org.

Please include this information when citing this paper: DOI: 10.3171/2013.1.FOCUS12380.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Preoperative axial precontrast (A), postcontrast T1-weighted (B), and T2-weighted (C) MR images revealing a right 10 × 12–mm skull base lesion situated within the right mastoid.

  • View in gallery

    Preoperative axial precontrast (A) and postcontrast T1-weighted (B and C) MR images revealing a left temporal tumor, which involves the vertical segment of the facial nerve.

  • View in gallery

    Preoperative temporal bone CT scan (A) and axial precontrast (B), postcontrast T1-weighted (C), and T2-weighted (D) MR images demonstrating a right enhancing temporal bone mass and enlargement of the facial nerve along the geniculate ganglion.

  • View in gallery

    Preoperative axial postcontrast T1-weighted MR image (A) and axial CT images (B and C) showing a spiculated lesion in the area of the geniculate segment of the facial nerve.

  • View in gallery

    Atypical facial nerve tumor illustration. Diagram by Lindsey Ross and Brian Nicholas. Printed with permission from Lindsey Ross, M.D.

References

  • 1

    Ahmadi NNewkirk KKim HJ: Facial nerve hemangioma: a rare case involving the vertical segment. Laryngoscope [epub ahead of print]2012

    • Search Google Scholar
    • Export Citation
  • 2

    Balkany TFradis MJafek BWRucker NC: Hemangioma of the facial nerve: role of the geniculate capillary plexus. Skull Base Surg 1:59631991

    • Search Google Scholar
    • Export Citation
  • 3

    Bartels LJPennington JKamerer DBBrowarsky I: Primary fallopian canal glomus tumors. Otolaryngol Head Neck Surg 102:1011051990

    • Search Google Scholar
    • Export Citation
  • 4

    Benoit MMNorth PEMcKenna MJMihm MCJohnson MMCunningham MJ: Facial nerve hemangiomas: vascular tumors or malformations?. Otolaryngol Head Neck Surg 142:1081142010

    • Search Google Scholar
    • Export Citation
  • 5

    Chung CJMukherji SFordham LBoydston WHudgins R: Geniculate ganglion meningioma. Pediatr Radiol 27:8478491997

  • 6

    Collin MBernardeschi DCazals-Hatem DSterkers O: Meningioma of geniculate ganglion: case report and review of the literature. Acta Otalaryngol [epub ahead of print]2012

    • Search Google Scholar
    • Export Citation
  • 7

    Connor SEGleeson MJOdell E: Extracranial glomus faciale tumour. J Laryngol Otol 122:9869892008

  • 8

    Deshmukh VRAlbuquerque FCZabramski JMSpetzler RF: Surgical management of cavernous malformations involving the cranial nerves. Neurosurgery 53:3523572003

    • Search Google Scholar
    • Export Citation
  • 9

    Dutcher PO JrBrackmann DE: Glomus tumor of the facial canal. A case report. Arch Otolaryngol Head Neck Surg 112:9869871986

  • 10

    Eby TLFisch UMakek MS: Facial nerve management in temporal bone hemangiomas. Am J Otol 13:2232321992

  • 11

    Escada PCapucho CSilva JMRuah CBVital JPPenha RS: Cavernous haemangioma of the facial nerve. J Laryngol Otol 111:8588611997

    • Search Google Scholar
    • Export Citation
  • 12

    Falcioni MRusso ATaibah ASanna M: Facial nerve tumors. Otol Neurotol 24:9429472003

  • 13

    Fierek OLaskawi RKunze E: Large intraosseous hemangioma of the temporal bone in a child. Ann Otol Rhinol Laryngol 113:3943982004

    • Search Google Scholar
    • Export Citation
  • 14

    Friedman ONeff BAWillcox TOKenyon LCSataloff RT: Temporal bone hemangiomas involving the facial nerve. Otol Neurotol 23:7607662002

    • Search Google Scholar
    • Export Citation
  • 15

    Gavilán JNistal MGavilán CCalvo M: Ossifying hemangioma of the temporal bone. Arch Otolaryngol Head Neck Surg 116:9659671990

    • Search Google Scholar
    • Export Citation
  • 16

    Gross BCCarlson MLMoore EJDriscoll CLOlsen KD: The intraparotid facial nerve schwannoma: a diagnostic and management conundrum. Am J Otolaryngol 33:4975042012

    • Search Google Scholar
    • Export Citation
  • 17

    Jabor MAAmedee RGGianoli GJ: Primary meningioma of the fallopian canal. South Med J 93:7177202000

  • 18

    Kania REBouccara DColombani JMMolas GSterkers O: Primary facial canal paraganglioma. Am J Otolaryngol 20:3183221999

  • 19

    Kettel K: Peripheral facial palsies due to tumors; pathology and clinical picture: a review of the literature and a report of three cases of intratemporal tumors of the facial nerve. AMA Arch Otolaryngol 69:2762921959

    • Search Google Scholar
    • Export Citation
  • 20

    Kim CSChang SOOh SHAhn SHHwang CHLee HJ: Management of intratemporal facial nerve schwannoma. Otol Neurotol 24:3123162003

    • Search Google Scholar
    • Export Citation
  • 21

    Kunzel JZenk JKoch MHornung JIro H: Paraganglioma of the facial nerve, a rare differential diagnosis for facial nerve paralysis: case report and review of the literature. Eur Arch Otorhinolaryngol 269:6936982012

    • Search Google Scholar
    • Export Citation
  • 22

    Larson TLTalbot JMWong ML: Geniculate ganglion meningiomas: CT and MR appearances. AJNR Am J Neuroradiol 16:114411461995

  • 23

    Luetje CMSyms CA IIILuxford WEStorper ISGlasscock ME IIIBrackmann DE: Meningiomas intrinsic to the geniculate ganglion. Am J Otol 18:3933971997

    • Search Google Scholar
    • Export Citation
  • 24

    Mafee MFRaofi BKimar AMuscato C: Glomus faciale, glomus jugulare, glomus tympanicum, glomus vagale carotid body tumors, and stimulating lesions. Role of MR imaging. Radiol North Am 38:105910762000

    • Search Google Scholar
    • Export Citation
  • 25

    Magliulo GAlla FRColicchio GTrasimeni G: Geniculate ganglion meningioma. Skull Base 20:1851882010

  • 26

    Mangham CACarberry JNBrackmann DE: Management of intratemporal vascular tumors. Laryngoscope 91:8678761981

  • 27

    Maniglia AJ: Intra and extracranial meningiomas involving the temporal bone. Laryngoscope 88:9 Pt 2 Suppl 121581978

  • 28

    McMonagle BAl-Sanosi ACroxson GFagan P: Facial schwannoma: results of a large case series and review. J Laryngol Otol 122:113911502008

    • Search Google Scholar
    • Export Citation
  • 29

    Mijangos SVMeltzer DE: Case 171: facial nerve hemangioma. Radiology 260:2963012011

  • 30

    Miyashita THoshikawa HKagawa MMori N: A case report of facial nerve hemangioma. Auris Nasus Larynx 34:5195222007

  • 31

    Nager GT: Meningioma involving the temporal bone: clinical and pathological aspects. Ir J Med Sci 41:69961966

  • 32

    O'Leary MShelton CGiddings NKwartler JBrackmann DE: Glomus tympanicum tumors: a clinical perspective. Laryngoscope 101:103810431991

    • Search Google Scholar
    • Export Citation
  • 33

    Olsen WLDillon WPKelly WMNorman DBrant-Zawadzki MNewton TH: MR imaging of paragangliomas. AJR Am J Roentgenol 148:2012041987

    • Search Google Scholar
    • Export Citation
  • 34

    Petrus LVLo WM: Primary paraganglioma of the facial nerve canal. AJNR Am J Neuroradiol 17:1711741996

  • 35

    Semaan MTSlattery WHBrackmann DE: Geniculate ganglion hemangiomas: clinical results and long-term follow-up. Otol Neurotol 31:6656702010

    • Search Google Scholar
    • Export Citation
  • 36

    Sherman JDDagnew EPensak MLvan Loveren HRTew JM Jr: Facial nerve neuromas: report of 10 cases and review of the literature. Neurosurgery 50:4504562002

    • Search Google Scholar
    • Export Citation
  • 37

    Shirazi MALeonetti JPMarzo SJAnderson DE: Surgical management of facial neuromas: lessons learned. Otol Neurotol 28:9589632007

    • Search Google Scholar
    • Export Citation
  • 38

    Wiggins RH IIIHarnsberger HRSalzman KLShelton CKertesz TRGlastonbury CM: The many faces of facial nerve schwannoma. AJNR Am J Neuroradiol 27:6946992006

    • Search Google Scholar
    • Export Citation
  • 39

    Wilkinson EPHoa MSlattery WH IIIFayad JNFriedman RASchwartz MS: Evolution in the management of facial nerve schwannoma. Laryngoscope 121:206520742011

    • Search Google Scholar
    • Export Citation

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 399 399 69
PDF Downloads 575 576 54
EPUB Downloads 0 0 0

PubMed

Google Scholar