Stereotactic radiosurgery for facial nerve hemangioma: Case report and systematic review

BACKGROUND

Facial nerve hemangiomas (FNHs) are rare tumors that primarily occur near the geniculate ganglion in the temporal bone. Despite their rarity, they can cause significant facial nerve dysfunction. The optimal management approach for FNHs remains uncertain, with surgery being the mainstay but subject to debate regarding the extent of resection and preservation of the facial nerve.

METHODS

Systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We queried the PubMed/Medline (accessed on 5 March 2024) electronic database using combinations of the following search terms and words text: "geniculate ganglion hemangioma", "ganglional hemangioma", "hemangioma of the facial nerve", "facial hemangioma", and "intratemporal hemangioma".

RESULTS

We identified a total of 30 literatures (321 patients). The most common site involved for the facial nerve hemangioma was the geniculate ganglion area followed by internal auditory canal, tympanic segment, labyrinthine segment and mastoid involvement. All patients were treated with conservative management or surgery. We report a 48-year-old female patient with HB grade 2 facial palsy and hemifacial spasm underwent SRS using Cyberknife technology. The treatment targeted the FNH in the left internal acoustic canal near the geniculate ganglion. Six months post-treatment, clinical improvement was evident, and lesion control was confirmed in a follow-up brain MRI.

CONCLUSION

The rarity of FNHs contributes to the lack of consensus on optimal management. This illustrative case demonstrates the feasibility of SRS as a standalone treatment for FNHs.

Differentiation of geniculate ganglion venous malformation from schwannoma: dynamic T1-weighted imaging provides unique diagnostic value

OBJECTIVE

To distinguish geniculate ganglion venous malformation (GGVM) from schwannoma (GGS) by using high-resolution CT (HRCT), routine MRI, and dynamic T1-weighted imaging (T1WI) characteristics.

METHODS

Surgically confirmed GGVMs and GGSs between 2016 and 2021 were retrospectively included. Preoperative HRCT, routine MR, and dynamic T1WI were performed on all patients. Clinical data, imaging characteristics including lesion size, involvement of facial nerve (FN), signal intensity, enhancement pattern on dynamic T1WI, and bone destruction on HRCT were evaluated. Logistic regression model was developed to identify independent factors for GGVMs, and the diagnostic performance was accessed by receiving operative curve (ROC) analysis. Histological characteristics were explored for both GGVMs and GGSs.

RESULTS

Twenty GGVMs and 23 GGSs with mean age of 31 were included. On dynamic T1WI, 18 GGVMs (18/20) showed "pattern A" enhancement (a progressive filling enhancement), while all 23 GGSs showed "pattern B" enhancement (a gradual whole-lesion enhancement) (p < 0.001). Thirteen GGVMs (13/20) showed the "honeycomb" sign whereas all GGS (23/23) showed extensive bone changes on HRCT (p < 0.001). Lesion size, involvement of FN segment, signal intensity on non-contrast T1WI and T2-weighted imaging (T2WI), and homogeneity on enhanced T1WI were obviously differed between two lesions (p < 0.001, p = 0.002, p < 0.001, p = 0.01, p = 0.02, respectively). Regression model showed the "honeycomb" sign and "pattern A" enhancement were independent risk factors. Histologically, GGVM was characterized by interwoven dilated and tortuous veins, while GGS was characterized by abundant spindle cells with dense arterioles or capillaries.

CONCLUSIONS

The "honeycomb" sign on HRCT and "pattern A" enhancement on dynamic T1WI are the most promising imaging characteristics for differentiating GGVM from GGS.

CLINICAL RELEVANCE STATEMENT

The characteristic sign and enhancement pattern on HRCT and dynamic T1-weighted imaging allow preoperative differentiation of geniculate ganglion venous malformation and schwannoma feasible, which will improve clinical management and benefit patient prognosis.

KEY POINTS

• The "honeycomb" sign on HRCT is a reliable finding to differentiate GGVM from GGS. • GGVM typically shows "pattern A" enhancement (focal enhancement of the tumor on early dynamic T1WI, followed by progressive contrast filling of the tumor in the delayed phase), while "pattern B" enhancement (gradual heterogeneous or homogeneous enhancement of the whole lesion) is observed in GGS on dynamic T1WI.

Facial nerve schwannoma: Case report and brief review of the literature

Schwannomas are rare nerve sheath tumors that can occur throughout the body, and are symptomatic based on location, size, and impingement on adjacent structures. These tumors are often benign lesions and occur sporadically or from genetic conditions such as neurofibromatosis. Schwannomas may arise from peripheral nerves, gastrointestinal nerves, spinal nerve roots and cranial nerves. Facial nerve schwannomas arise from cranial nerve VII, commonly involving the geniculate ganglion, labyrinthine segment, and internal auditory canal. While small lesions are asymptomatic, larger lesions can cause facial nerve paralysis, and facial spasms. Lesions in the internal auditory canal can cause hearing loss, tinnitus, vertigo, and otalgia. High-resolution CT imaging and MRI imaging are useful for distinguishing between other pathologies that arise from the same region. High-resolution CT scans can show bony degeneration of nearby structures such as the labyrinth or ossicles. MRI imaging shows hypo intensity on T1 imaging, and hyperintensity on T2 imaging. On T1 postcontrast, enhancement can be homogenous or heterogeneous with cystic degeneration if the lesion is large. Nodular enhancement is commonly seen on facial nerve schwannomas within the internal auditory canal. Vestibular schwannomas involving CN VIII are more common, and appear similar to facial nerve schwannomas, but can be distinguished apart due to growth in the geniculate ganglion and/or the labyrinthine segment. Management of asymptomatic or mild lesions is typically conservative with follow up imaging, and surgery for larger lesions. Here, we present a case of a facial nerve schwannoma in a 57-year-old woman.

Imaging the facial nerve: A contemporary review of anatomy and pathology

PURPOSE

The facial nerve is the seventh paired cranial nerve which anatomically can be divided into six distinct segments. There are a wide range of pathologies that may occur along each segment of the nerve. The aim of this pictorial review is to untangle the complex appearances of the facial nerve, both in its normal anatomical course and when affected by pathology.

METHOD

This review takes an evidence-based segmental approach to the evaluation of the facial nerve in terms of its anatomy and clinical features of common pathologies affecting specific segments of the nerve. The typical multimodal radiological findings of common facial nerve pathologies are included in the review using imaging from select pathologically confirmed cases.

RESULTS

A wide range of pathologies ranging from congenital abnormalities to inflammatory, infective and neoplastic processes can affect the facial nerve. As select segments of the nerve are better evaluated on certain imaging modalities a clear understanding of the anatomy and clinical features associated with specific facial nerve pathologies enables the radiologist to tailor the imaging test to best answer the clinical question.

CONCLUSIONS

This review provides a segmental clinical-radiological approach to imaging the facial nerve. In addition, recent developments in facial nerve imaging that may come into mainstream use in the near future are touched upon.

A case of a facial nerve venous malformation presenting with crocodile tear syndrome

Background:

Crocodile tears syndrome, also known as Bogorad syndrome, is characterized by lacrimation secondary to olfactory and gustatory stimuli and mastication. Crocodile tear syndrome is typically encountered as an uncommon complication of Bell’s palsy and usually occurs during the recovery phase of the disease course.

Case Description:

We present a case of a 39-year-old male who presented with facial paralysis with ipsilateral crocodile tear syndrome caused by a slow flow venous malformation of the petrous bone and facial nerve.

Conclusion:

We present a case of crocodile tear syndrome caused by a facial nerve venous malformation. To the best of our knowledge, this is the only case reported in literature.

Facial nerve venous malformation: A radiologic and histopathologic review of 11 cases

Objective

The purpose of this article was to provide a combined pathologic and radiologic review of previous pathologically diagnosed facial nerve “hemangiomas” to confirm that these lesions are most characteristic of venous malformations rather than neoplasms.

Study Design

Retrospective radiologic, clinical, and histopathologic review of all patients with a previous pathologically diagnosed facial nerve hemangioma of the temporal bone who underwent computed tomography or magnetic resonance imaging (MRI) were included. A consensus radiologic review for characteristic features and pathologic analysis was performed.

Materials and Methods

A panel of 4 neuroradiologists retrospectively analyzed CT and MRI exams for 11 facial nerve hemangiomas and provided a consensus agreement on the characteristic imaging features. Concurrently, two neuropathologists reevaluated archived tissue specimens from these lesions and applied additional immunohistochemical and histochemical stains including D240, CD31, smooth muscle actin (SMA), Verhoeff Van Gieson (VVG) and glucose transporter 1 (GLUT1).

Results

Lesions were composed of dilated vascular spaces with a simple, CD31‐positive endothelial lining and a smooth muscle component. All lesions were negative for markers found in arterial and lymphatic malformations and infantile hemangiomas. They had characteristic radiologic features previously ascribed to facial nerve hemangiomas. Namely, these lesions are typically T1 isointense or hypointense and T2 hyperintense relative to cerebral cortex and heterogeneously enhance on MRI. Bony canal expansion and erosion, intralesional calcification, and intracranial extension are common.

Conclusions

On the basis of this radiologic and pathologic review, these lesions are best characterized as venous malformations.

Level of Evidence

4

Cranial Nerve Schwannomas: Diagnostic Imaging Approach

Schwannomas are benign nerve sheath tumors that may arise along the complex course of the cranial nerves (CNs), anywhere in the head and neck. Sound knowledge of the CN anatomy and imaging features of schwannomas is paramount for making the correct diagnosis. In this article, we review approaches to diagnosing CN schwannomas by describing their imaging characteristics and the associated clinical presentations. Relevant anatomic considerations are highlighted by using illustrative examples and key differential diagnoses categorized according to regions, which include the anterior skull base, orbit, cavernous sinus, basal cisterns, and neck. The clinical presentations associated with CN schwannomas vary and range from no symptoms to symptoms caused by mass effect or CN deficits. Individuals with the inherited disorder neurofibromatosis type 2 are predisposed to multiple schwannomas. When a lesion follows the course of a CN, the radiologist's roles are to confirm the imaging features of schwannoma and exclude appropriate differential considerations. The characteristic imaging features of CN schwannomas reflect their slow growth as benign neoplasms and include circumscribed margins, displacement of local structures, and smooth expansion of osseous foramina. These neoplasms exhibit various degrees of solid enhancement, often with internal cystic spaces on magnetic resonance (MR) and computed tomographic (CT) images and heterogeneous high signal intensity specifically on T2-weighted MR images. Clinical and/or imaging evidence of end-organ compromise of the involved CN may exist and aid in the identification of the nerve of origin. With a detailed understanding of the course of the CNs, the diagnostic features of CN schwannomas, and the correlation between these data and the associated clinical presentations of these tumors, the radiologist can have a key role in the diagnosis of CN schwannomas and the treatment planning for affected patients. (©)RSNA, 2016.

Neuroendocrine adenoma of middle ear with new bone formation and review of literature

Neuroendocrine adenoma of the middle ear has been described in literature as middle ear adenoma with neuroendocrine differentiation or carcinoid tumor. While there have been several case reports describing imaging features of carcinoid tumors of the ear and middle ear adenomas, in our literature review, we have not found a single case where bone formation is described as a prominent radiological feature. We report a first documented case of middle ear carcinoid tumor with new bone formation demonstrated on CT imaging and performed a review literature regarding the tumor. A differential diagnosis of neuroendocrine adenoma of the middle ear should be considered when there is prominent bone formation with a soft tissue mass in the middle ear on CT imaging.

Facial nerve hemangioma of the geniculate ganglion: an endoscopic surgical approach

Facial nerve hemangiomas are rare benign tumors arising from the venous plexus surrounding the facial nerve. Surgical management of these tumors is controversial. The goal of surgery is complete tumor removal with restoration of facial nerve function and preservation of hearing, wherever possible. The approaches most used are the translabyrinthine and middle cranial fossa approaches. In this report, we describe the first facial hemangioma treated with an endoscopic transcanal approach, combined with a retroauricular transmastoid minicraniotomy for closure of the dural defect. A great auricular nerve graft was used to reconnect interrupted nerve segments. Histopathological examination confirmed the diagnosis of a hemangioma of the first genu of the facial nerve. With magnification of the structures, the transcanal endoscopic approach allowed a radical excision of the neoplasm permitting hearing function preservation, with the possibility to work with a minimally invasive approach with respect to the labyrinthine block and cochlea. Compared to a middle cranial fossa approach, the transcanal endoscopic approach avoided labyrinthine block removal and brain retraction.

Imaging spectrum of facial nerve lesions

The facial nerve is affected by a wide variety of pathologies, including congenital, traumatic, inflammatory, and neoplastic conditions. Imaging plays a vital role in the diagnosis of these pathologies. The facial nerve has a complex anatomy and course. A strong grasp of normal facial nerve anatomy is essential for the radiologist to maintain a high level of diagnostic sensitivity. This article details the normal imaging anatomy of the facial nerve and the imaging features of common facial nerve pathologies.

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

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.