Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Case Report
Facial neuroma masquerading as acoustic neuroma Eli T. Sayegh a, Gurvinder Kaur a, Michael E. Ivan b, Orin Bloch a, Steven W. Cheung c, Andrew T. Parsa a,⇑ a
Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, 676 N. St. Clair Street, Suite 2210, Chicago, IL 60611-2911, USA Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA c Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, USA b
a r t i c l e
i n f o
Article history: Received 13 November 2013 Accepted 13 December 2013 Available online xxxx Keywords: Acoustic neuroma Cerebellopontine angle Facial nerve neuroma Facial neuroma Internal acoustic canal
a b s t r a c t Facial nerve neuromas are rare benign tumors that may be initially misdiagnosed as acoustic neuromas when situated near the auditory apparatus. We describe a patient with a large cystic tumor with associated trigeminal, facial, audiovestibular, and brainstem dysfunction, which was suspicious for acoustic neuroma on preoperative neuroimaging. Intraoperative investigation revealed a facial nerve neuroma located in the cerebellopontine angle and internal acoustic canal. Gross total resection of the tumor via retrosigmoid craniotomy was curative. Transection of the facial nerve necessitated facial reanimation 4 months later via hypoglossal-facial cross-anastomosis. Clinicians should recognize the natural history, diagnostic approach, and management of this unusual and mimetic lesion. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Facial nerve neuromas (FNN) are rare benign tumors that arise from the myelin-producing Schwann cell sheath [1]. FNN and acoustic neuromas represent about 1.9% and 81%, respectively, of all cerebellopontine angle (CPA) tumors [2]. FNN can arise anywhere along the course of the facial nerve, from the CPA to the extratemporal peripheral aspect [3], but show a predilection for the labyrinthine and tympanic segments [1]. FNN display comparable growth rates to acoustic neuromas in the vicinity of 1.4 mm/ year [4]. When situated near the auditory apparatus, FNN may cause hearing loss, tinnitus, and vertigo, mimicking acoustic neuromas. Progressive or recurrent facial paresis, sometimes associated with facial twitching, is suggestive of FNN [5]. The most common presenting symptoms are facial weakness (63%), hearing loss (51%), tinnitus (21%), vestibular dysfunction (14%), and an ear canal mass (11%) [5]. Preservation of hearing and facial function critically depends upon timely diagnosis [5].
2. Case report Two months before admission, a 23-year-old man developed tinnitus, reduced left-sided hearing, and right arm numbness. Six ⇑ Corresponding author. Tel.: +1 312 695 1801; fax: +1 312 695 0225. E-mail address: [email protected] (A.T. Parsa).
weeks later, he experienced worsening left-sided symptoms including complete deafness, unremitting tinnitus, facial numbness, slight facial weakness, dysgeusia, and throbbing headaches, as well as constant disequilibrium and intermittent vertigo. His past medical history included migraine, obstructive sleep apnea, and seizures that had subsided and were not managed with medication. His family history was remarkable only for breast cancer in his grandmother. Physical examination and audiologic evaluation revealed severe left-sided sensorineural hearing loss. Horizontal upbeating nystagmus was noted. Sensation was lost in the trigeminal (V1–V3) distribution and decreased in the right forearm. Bilateral facial strength was reduced. The patient had leftward tongue deviation, hoarse vocal quality, and left-sided lingual, buccal, and labial dysfunction. Right-sided coordination was impaired. CT scan identified a large, 4 3.5 cm hypodense lesion in the posterior fossa near the internal carotid artery suspicious for acoustic neuroma. MRI demonstrated a rim-enhancing and cystic 47 mm lesion in the left CPA with a solid component in the internal acoustic canal (IAC) (Fig. 1A, B). Treatment options were discussed and included observation, primary radiation, and microsurgery with adjuvant radiosurgery. The patient was taken to the operating room for retrosigmoid craniotomy. After cerebellar retraction, microscopy demonstrated a cystic tumor and biopsy revealed spindle cell histology consistent with schwannoma. Facial nerve neuromonitoring showed unusually robust stimulation on the posterior aspect of the tumor capsule, which was dissected in a piecemeal fashion. The IAC was drilled out via petrosectomy, the superior vestibular nerve was
http://dx.doi.org/10.1016/j.jocn.2013.12.029 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Sayegh ET et al. Facial neuroma masquerading as acoustic neuroma. J Clin Neurosci (2014), http://dx.doi.org/10.1016/ j.jocn.2013.12.029
2
Case Report / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Fig. 1. Preoperative (A) axial T1-weighted post-contrast and (B) axial fluid-attenuated inversion recovery MRI showing a rim-enhancing, cystic lesion measuring 47 mm in the left cerebellopontine angle with a solid component in the internal acoustic canal. (C) Postoperative axial T1-weighted post-contrast MRI showing gross total excision of the tumor and continuity of the auditory nerve.
excised, and the auditory nerve was preserved. The facial nerve was identified in the most lateral recess of its course from the cisternal compartment. At the level of the porus acusticus there was continuity of the mass with the facial nerve into the IAC. Sparing of the cochlear and vestibular nerves supported the diagnosis of FNN. The facial nerve was transected and delivered lateromedially, and, considering the patient’s young age, the tumor was completely excised. Postoperative MRI showed gross total excision and continuity of the auditory nerve (Fig. 1C), and the postoperative course was unremarkable. Neurological examination confirmed left-sided deafness and grade VI House-Brackmann (HB) facial palsy and showed improved facial sensation and vocal quality, right-beating nystagmus, mild dysarthria, dysphagia, leftward tongue deviation, and persistent tinnitus. He was discharged on the third postoperative day on a dexamethasone taper. Four months later the patient underwent end-to-end hypoglossal-facial cross-anastomosis for facial reanimation.
3. Discussion A subset of FNN are limited to the CPA and/or IAC and mimic acoustic neuromas due to hearing loss and less frequent facial paresis [6]. Bone-targeted high-resolution CT scan of the temporal bone should be performed first to visualize the facial canal, detect facial nerve enlargement, and assess bony destruction [5]. Although MRI cannot discriminate between FNN and intracanalicular acoustic neuromas, FNN is suggested by facial nerve or geniculate ganglion enhancement [2,3] or deformation of the IAC or labyrinthine facial nerve canal [7]. A normal auditory brainstem response and abnormal electroneuronography support the diagnosis of FNN [8]. While facial paralysis can occur in 1% to 10.5% of acoustic neuromas [9,10], a facial nerve etiology should be favored. Although surgical resection is the gold standard treatment for FNN, the benefit of hearing recovery must be weighed against the inevitable HB grade III or higher facial palsy even after reconstruction [11]. Surgery is indicated without delay in patients with progressive facial palsy, brainstem compression or hydrocephalus, inner ear invasion [12,13], or deterioration to grade IV facial function [7,14]. Early intervention minimizes local structural destruction, limits the duration of nerve degeneration, and facilitates a shorter anastomotic distance for optimal facial grafting [15].
Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Acknowledgements This work was supported by grants from the Howard Hughes Medical Institute (E.T.S., G.K.), the National Research Education Foundation through the American Association of Neurological Surgeons (M.E.I.), the Reza and Georgianna Khatib Endowed Chair in Skull Base Tumor Surgery at UCSF (A.T.P.), and the Michael J. Marchese Professor and Chair at Northwestern University (A.T.P.). References [1] Lipkin AF, Coker NJ, Jenkins HA, et al. Intracranial and intratemporal facial neuroma. Otolaryngol Head Neck Surg 1987;96:71–9. [2] Günther M, Danckwardt-Lillieström N, Gudjonsson O, et al. Surgical treatment of patients with facial neuromas–a report of 26 consecutive operations. Otol Neurotol 2010;31:1493–7. [3] Yamaki T, Morimoto S, Ohtaki M, et al. Intracranial facial nerve neurinoma: surgical strategy of tumor removal and functional reconstruction. Surg Neurol 1998;49:538–46. [4] McRackan TR, Rivas A, Wanna GB, et al. Facial nerve outcomes in facial nerve schwannomas. Otol Neurotol 2012;33:78–82. [5] Sherman JD, Dagnew E, Pensak ML, et al. Facial nerve neuromas: report of 10 cases and review of the literature. Neurosurgery 2002;50:450–6. [6] Gulya AJ, Stern NM. Facial nerve neuroma. Ann Otol Rhinol Laryngol 1993;102:478–80. [7] Angeli SI, Brackmann DE. Is surgical excision of facial nerve schwannomas always indicated? Otolaryngol Head Neck Surg 1997;117:S144–7. [8] Som PM, Bergeron RT. Head and neck imaging. St Louis, MO: Mosby Year Book Inc.; 1991. [9] Lanman TH, Brackmann DE, Hitselberger WE, et al. Report of 190 consecutive cases of large acoustic tumors (vestibular schwannoma) removed via the translabyrinthine approach. J Neurosurg 1999;90:617–23. [10] Zhang X, Fei Z, Chen YJ, et al. Facial nerve function after excision of large acoustic neuromas via the suboccipital retrosigmoid approach. J Clin Neurosci 2005;12:405–8. [11] Minovi A, Vosschulte R, Hofmann E, et al. Facial nerve neuroma: surgical concept and functional results. Skull Base 2004;14:195–200 [discussion 2001]. [12] Liu R, Fagan P. Facial nerve schwannoma: surgical excision versus conservative management. Ann Otol Rhinol Laryngol 2001;110:1025–9. [13] Symon L, Cheesman AD, Kawauchi M, et al. Neuromas of the facial nerve: a report of 12 cases. Br J Neurosurg 1993;7:13–22. [14] Kirazli T, Oner K, Bilgen C, et al. Facial nerve neuroma: clinical, diagnostic, and surgical features. Skull Base 2004;14:115–20. [15] McMonagle B, Al-Sanosi A, Croxson G, et al. Facial schwannoma: results of a large case series and review. J Laryngol Otol 2008;122:1139–50.
Please cite this article in press as: Sayegh ET et al. Facial neuroma masquerading as acoustic neuroma. J Clin Neurosci (2014), http://dx.doi.org/10.1016/ j.jocn.2013.12.029
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Case Report
Facial neuroma masquerading as acoustic neuroma Eli T. Sayegh a, Gurvinder Kaur a, Michael E. Ivan b, Orin Bloch a, Steven W. Cheung c, Andrew T. Parsa a,⇑ a
Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, 676 N. St. Clair Street, Suite 2210, Chicago, IL 60611-2911, USA Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA c Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, USA b
a r t i c l e
i n f o
Article history: Received 13 November 2013 Accepted 13 December 2013 Available online xxxx Keywords: Acoustic neuroma Cerebellopontine angle Facial nerve neuroma Facial neuroma Internal acoustic canal
a b s t r a c t Facial nerve neuromas are rare benign tumors that may be initially misdiagnosed as acoustic neuromas when situated near the auditory apparatus. We describe a patient with a large cystic tumor with associated trigeminal, facial, audiovestibular, and brainstem dysfunction, which was suspicious for acoustic neuroma on preoperative neuroimaging. Intraoperative investigation revealed a facial nerve neuroma located in the cerebellopontine angle and internal acoustic canal. Gross total resection of the tumor via retrosigmoid craniotomy was curative. Transection of the facial nerve necessitated facial reanimation 4 months later via hypoglossal-facial cross-anastomosis. Clinicians should recognize the natural history, diagnostic approach, and management of this unusual and mimetic lesion. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Facial nerve neuromas (FNN) are rare benign tumors that arise from the myelin-producing Schwann cell sheath [1]. FNN and acoustic neuromas represent about 1.9% and 81%, respectively, of all cerebellopontine angle (CPA) tumors [2]. FNN can arise anywhere along the course of the facial nerve, from the CPA to the extratemporal peripheral aspect [3], but show a predilection for the labyrinthine and tympanic segments [1]. FNN display comparable growth rates to acoustic neuromas in the vicinity of 1.4 mm/ year [4]. When situated near the auditory apparatus, FNN may cause hearing loss, tinnitus, and vertigo, mimicking acoustic neuromas. Progressive or recurrent facial paresis, sometimes associated with facial twitching, is suggestive of FNN [5]. The most common presenting symptoms are facial weakness (63%), hearing loss (51%), tinnitus (21%), vestibular dysfunction (14%), and an ear canal mass (11%) [5]. Preservation of hearing and facial function critically depends upon timely diagnosis [5].
2. Case report Two months before admission, a 23-year-old man developed tinnitus, reduced left-sided hearing, and right arm numbness. Six ⇑ Corresponding author. Tel.: +1 312 695 1801; fax: +1 312 695 0225. E-mail address: [email protected] (A.T. Parsa).
weeks later, he experienced worsening left-sided symptoms including complete deafness, unremitting tinnitus, facial numbness, slight facial weakness, dysgeusia, and throbbing headaches, as well as constant disequilibrium and intermittent vertigo. His past medical history included migraine, obstructive sleep apnea, and seizures that had subsided and were not managed with medication. His family history was remarkable only for breast cancer in his grandmother. Physical examination and audiologic evaluation revealed severe left-sided sensorineural hearing loss. Horizontal upbeating nystagmus was noted. Sensation was lost in the trigeminal (V1–V3) distribution and decreased in the right forearm. Bilateral facial strength was reduced. The patient had leftward tongue deviation, hoarse vocal quality, and left-sided lingual, buccal, and labial dysfunction. Right-sided coordination was impaired. CT scan identified a large, 4 3.5 cm hypodense lesion in the posterior fossa near the internal carotid artery suspicious for acoustic neuroma. MRI demonstrated a rim-enhancing and cystic 47 mm lesion in the left CPA with a solid component in the internal acoustic canal (IAC) (Fig. 1A, B). Treatment options were discussed and included observation, primary radiation, and microsurgery with adjuvant radiosurgery. The patient was taken to the operating room for retrosigmoid craniotomy. After cerebellar retraction, microscopy demonstrated a cystic tumor and biopsy revealed spindle cell histology consistent with schwannoma. Facial nerve neuromonitoring showed unusually robust stimulation on the posterior aspect of the tumor capsule, which was dissected in a piecemeal fashion. The IAC was drilled out via petrosectomy, the superior vestibular nerve was
http://dx.doi.org/10.1016/j.jocn.2013.12.029 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Sayegh ET et al. Facial neuroma masquerading as acoustic neuroma. J Clin Neurosci (2014), http://dx.doi.org/10.1016/ j.jocn.2013.12.029
2
Case Report / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Fig. 1. Preoperative (A) axial T1-weighted post-contrast and (B) axial fluid-attenuated inversion recovery MRI showing a rim-enhancing, cystic lesion measuring 47 mm in the left cerebellopontine angle with a solid component in the internal acoustic canal. (C) Postoperative axial T1-weighted post-contrast MRI showing gross total excision of the tumor and continuity of the auditory nerve.
excised, and the auditory nerve was preserved. The facial nerve was identified in the most lateral recess of its course from the cisternal compartment. At the level of the porus acusticus there was continuity of the mass with the facial nerve into the IAC. Sparing of the cochlear and vestibular nerves supported the diagnosis of FNN. The facial nerve was transected and delivered lateromedially, and, considering the patient’s young age, the tumor was completely excised. Postoperative MRI showed gross total excision and continuity of the auditory nerve (Fig. 1C), and the postoperative course was unremarkable. Neurological examination confirmed left-sided deafness and grade VI House-Brackmann (HB) facial palsy and showed improved facial sensation and vocal quality, right-beating nystagmus, mild dysarthria, dysphagia, leftward tongue deviation, and persistent tinnitus. He was discharged on the third postoperative day on a dexamethasone taper. Four months later the patient underwent end-to-end hypoglossal-facial cross-anastomosis for facial reanimation.
3. Discussion A subset of FNN are limited to the CPA and/or IAC and mimic acoustic neuromas due to hearing loss and less frequent facial paresis [6]. Bone-targeted high-resolution CT scan of the temporal bone should be performed first to visualize the facial canal, detect facial nerve enlargement, and assess bony destruction [5]. Although MRI cannot discriminate between FNN and intracanalicular acoustic neuromas, FNN is suggested by facial nerve or geniculate ganglion enhancement [2,3] or deformation of the IAC or labyrinthine facial nerve canal [7]. A normal auditory brainstem response and abnormal electroneuronography support the diagnosis of FNN [8]. While facial paralysis can occur in 1% to 10.5% of acoustic neuromas [9,10], a facial nerve etiology should be favored. Although surgical resection is the gold standard treatment for FNN, the benefit of hearing recovery must be weighed against the inevitable HB grade III or higher facial palsy even after reconstruction [11]. Surgery is indicated without delay in patients with progressive facial palsy, brainstem compression or hydrocephalus, inner ear invasion [12,13], or deterioration to grade IV facial function [7,14]. Early intervention minimizes local structural destruction, limits the duration of nerve degeneration, and facilitates a shorter anastomotic distance for optimal facial grafting [15].
Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Acknowledgements This work was supported by grants from the Howard Hughes Medical Institute (E.T.S., G.K.), the National Research Education Foundation through the American Association of Neurological Surgeons (M.E.I.), the Reza and Georgianna Khatib Endowed Chair in Skull Base Tumor Surgery at UCSF (A.T.P.), and the Michael J. Marchese Professor and Chair at Northwestern University (A.T.P.). References [1] Lipkin AF, Coker NJ, Jenkins HA, et al. Intracranial and intratemporal facial neuroma. Otolaryngol Head Neck Surg 1987;96:71–9. [2] Günther M, Danckwardt-Lillieström N, Gudjonsson O, et al. Surgical treatment of patients with facial neuromas–a report of 26 consecutive operations. Otol Neurotol 2010;31:1493–7. [3] Yamaki T, Morimoto S, Ohtaki M, et al. Intracranial facial nerve neurinoma: surgical strategy of tumor removal and functional reconstruction. Surg Neurol 1998;49:538–46. [4] McRackan TR, Rivas A, Wanna GB, et al. Facial nerve outcomes in facial nerve schwannomas. Otol Neurotol 2012;33:78–82. [5] Sherman JD, Dagnew E, Pensak ML, et al. Facial nerve neuromas: report of 10 cases and review of the literature. Neurosurgery 2002;50:450–6. [6] Gulya AJ, Stern NM. Facial nerve neuroma. Ann Otol Rhinol Laryngol 1993;102:478–80. [7] Angeli SI, Brackmann DE. Is surgical excision of facial nerve schwannomas always indicated? Otolaryngol Head Neck Surg 1997;117:S144–7. [8] Som PM, Bergeron RT. Head and neck imaging. St Louis, MO: Mosby Year Book Inc.; 1991. [9] Lanman TH, Brackmann DE, Hitselberger WE, et al. Report of 190 consecutive cases of large acoustic tumors (vestibular schwannoma) removed via the translabyrinthine approach. J Neurosurg 1999;90:617–23. [10] Zhang X, Fei Z, Chen YJ, et al. Facial nerve function after excision of large acoustic neuromas via the suboccipital retrosigmoid approach. J Clin Neurosci 2005;12:405–8. [11] Minovi A, Vosschulte R, Hofmann E, et al. Facial nerve neuroma: surgical concept and functional results. Skull Base 2004;14:195–200 [discussion 2001]. [12] Liu R, Fagan P. Facial nerve schwannoma: surgical excision versus conservative management. Ann Otol Rhinol Laryngol 2001;110:1025–9. [13] Symon L, Cheesman AD, Kawauchi M, et al. Neuromas of the facial nerve: a report of 12 cases. Br J Neurosurg 1993;7:13–22. [14] Kirazli T, Oner K, Bilgen C, et al. Facial nerve neuroma: clinical, diagnostic, and surgical features. Skull Base 2004;14:115–20. [15] McMonagle B, Al-Sanosi A, Croxson G, et al. Facial schwannoma: results of a large case series and review. J Laryngol Otol 2008;122:1139–50.
Please cite this article in press as: Sayegh ET et al. Facial neuroma masquerading as acoustic neuroma. J Clin Neurosci (2014), http://dx.doi.org/10.1016/ j.jocn.2013.12.029
