Cervical spinal schwannoma

Cervical spinal schwannoma

Spinal schwannoma are most frequently seen in the cervical and lumbar regions, far more frequently than in the thoracic spine.

Classification

Asazuma Classification

1).


Eden’s classification for dumbbell tumors of the spine, long considered a “gold standard,”

no longer is sufficient to determine surgical strategy in view of recent advances in computed tomography and magnetic resonance imaging.

Treatment

Cervical dumbbell spinal schwannomas with an extraspinal extension through the intervertebral foramina pose significant challenges for complete resection while avoiding injury to the vertebral artery and preserving the integrity of the cervical spine. Posterior approaches may require an extensive soft-tissue dissection and bone removal with potential spinal instability. Moreover, they offer only a limited access to an extraspinal tumor component that entails an additional anterior approach for complete resection of a dumbbell-shaped lesion.

Goga et al., used an anterolateral transforaminal approach that preserves the bony elements of the intervertebral foramen and offers a comprehensive access to the extraspinal, foraminal and intraspinal/intradural components of a cervical dumbbell tumor 2).

Outcome

Cervical spinal schwannoma is benign, and outcomes after surgical resection are generally excellent. A surgical dilemma sometimes arises as to whether to perform total tumor removal, which carries a risk of sacrificing the nerve root, or subtotal removal, where the risk can be tumor recurrence.

Case series

Chowdhury et al. reported schwannomas arising from C1, C2 and C3 spinal nerve roots were regarded as high cervical spinal schwannoma. All patients with high cervical spinal schwannomas that were consecutively operated microneurosurgically from 2006-2010 were included in the study. Postoperatively all patients were followed up regularly both clinically and neuro-radiologically (MRI of cervical spine).

Average follow up was 31.5 months. The mean age of the series was 35.8 years (range 10-61 years). There were 8 male and 7 female patients. The mean duration of symptoms at the time of presentation was 32 months (range 06 months-5 years). Two schwannomas were completely extradural, seven were intradural and rest six were interdural or hourglass type (both extra and intradural) as identified during surgery. The standard midline posterior approach was used in all patients. A C2 hemilaminectomyor C2 laminectomy with or without cutting of posterior arch of atlas was used for most intradural and large interdural C2 schwannomas. Tumor removal was complete in all cases. Preservation of the nerve root fibers was not possible in 9 cases and was possible only in 3 cases. In two patients CSF leak developed after operation. One patient who had severe myelopathic features with bed sore failed toimprove and expired 5 months after operation. Rest of the patients showed postoperative improvement in their preoperative symptoms and returned to their normal life by the end of sixth month. There was no tumor recurrence in any patient till last follow up.

Proper 3-D anatomical orientation & physiological knowledge, deep neuro-radiological observation,pathological appreciations and micro-neurosurgical skill and expertization can make the surgical management of these tumors ( in a surgically complex site) simple with gratifying result (i.e.neurological outcome) without extensive bone removal or soft tissue manipulation through a standard midline posterior approach 3).


Thirty cases of cervical schwannomas treated by Yamane et al. were retrospectively reviewed;initial symptoms, tumor location, Eden classification, surgical method, functional outcome, and tumor recurrence were investigated. All permanent motor deficits were the result of resecting functionally relevant nerve roots (i.e., C5-8). The rate of permanent sensory deficit was 11% after C1-4 nerve root resection, and 67% after C5-8 nerve root resection. Permanent neurological deficits occurred in 14% of patients younger than 40 years and 38% of those older than 40. Dumbbell tumors were associated with the need for total or ventral nerve root transection, as well as with a high incidence of tumor recurrence. The incidence of permanent neurological deficit was significantly higher in patients undergoing C5-8 nerve root resection, and tended to be higher in those over 40 4).


Forty-two patients with cervical dumbbell tumors were analyzed retrospectively using a new three-dimensional classification.

To establish optimal surgical strategies, we considered shapes and three-dimensional locations of cervical dumbbell tumors based on diagnostic images and intraoperative findings.

Forty-two cervical dumbbell tumors were characterized according to transverse-section images (Toyama classification; nine types) and craniocaudal extent of intervertebral and transverse foraminal involvement (IF and TF staging; three stages each).

Type IIIa tumors, involving dura plus an intervertebral foramen, accounted for 50% of cases. A posterior approach was used in 35 patients; 7 others underwent a combined anterior and posterior approach. A posterior approach was used for all type IIa and IIIa tumors, and for some type IIIb (upper cervical), IV, and VI tumors; a combined posterior and anterior approach was used for type IIb and the remainder of type IV and VI. Reconstruction was performed using spinal instrumentation in 4 patients (9.5%). Resection was subtotal in 6 patients (14.3%) and total in 36 (85.7%).

Systematic, imaging-based three-dimensional characterization of shape and location of cervical dumbbell tumors is essential for planning optimal surgery. The classification used here fulfills this need 5).


Case reports

Pokharel et al. reported a case of extradural cervical schwannoma in a 14-year-old boy with swelling in the posterior triangle of his neck. The radiological features suggested solitary extradural cervical schwannoma which was confirmed later by histopathological findings. There were no postoperative neurological complications 6)


Perry et al. reported in 2019 the third case of synchronously presenting primary progressive multiple sclerosis (MS) and spinal schwannoma. A 65-year-old man presented with six months of progressive weakness and pain of the right shoulderforearm, and handMRI demonstrated a contrast-enhancing transforaminal lesion at C7, most consistent with a benign nerve sheath tumor. Additional history disclosed several years of worsening fatigue, accompanied by bilateral weakness and lancinating leg pain. MRI of the neuraxis demonstrated abnormalities consistent with chronic demyelinating disease intracranially and within the spinal cordcerebrospinal fluid (CSF) analysis revealed nine oligoclonal bands and an elevated IgG index, resulting in the diagnosis of MS. Given the symptomatic C7 lesion, the patient subsequently underwent right C6-C7 facetectomygross total resection of the tumor, and C6-T1 posterior instrumented fusion. Postoperatively, the patient rapidly recovered normal right upper extremity function, and pathology confirmed benign schwannoma. Synchronously presenting co-morbid neurologic diagnoses are exceedingly rare. Nonetheless, the high incidence and protean nature of MS make it particularly susceptible to such confounding clinical cases. Correspondingly, MS should be considered when neurologic abnormalities are not compatible with a focal radiographic lesion, and the present report emphasizes the value of a good history and exam in unraveling similarly challenging cases 7).

References

1) , 5)

Asazuma T, Toyama Y, Maruiwa H, Fujimura Y, Hirabayashi K. Surgical strategy for cervical dumbbell tumors based on a three-dimensional classification. Spine (Phila Pa 1976). 2004 Jan 1;29(1):E10-4. PubMed PMID: 14699292.
2)

Goga C, Türe U. The Anterolateral Transforaminal Approach to a Dumbbell Schwannoma of the C3 Nerve Root. A 3-Dimensional Operative Video. Neurosurgery. 2014 Sep 24. [Epub ahead of print] PubMed PMID: 25255264.
3)

Chowdhury FH, Haque MR, Sarker MH. High cervical spinal schwannoma; microneurosurgical management: an experience of 15 cases. Acta Neurol Taiwan. 2013 Jun;22(2):59-66. PubMed PMID: 24030037.
4)

Yamane K, Takigawa T, Tanaka M, Osaki S, Sugimoto Y, Ozaki T. Factors predicting clinical impairment after surgery for cervical spinal schwannoma. Acta Med Okayama. 2013;67(6):343-9. PubMed PMID: 24356718.
6)

Pokharel A, Rao TS, Basnet P, Pandey B, Mayya NJ, Jaiswal S. Extradural cervical spinal schwannoma in a child: a case report and review of the literature. J Med Case Rep. 2019 Jul 17;13(1):230. doi: 10.1186/s13256-019-2108-6. PubMed PMID: 31311599; PubMed Central PMCID: PMC6636037.
7)

Perry A, Peters P, Graffeo CS, Carlstrom LP, Krauss WE. Synchronous Presentation of a Cervical Spinal Schwannoma and Primary Progressive Multiple Sclerosis in a 65-year-old Man. Cureus. 2019 Mar 4;11(3):e4176. doi: 10.7759/cureus.4176. PubMed PMID: 31093475; PubMed Central PMCID: PMC6502288.

Comprehensive Management of Vestibular Schwannoma

Comprehensive Management of Vestibular Schwannoma

Comprehensive Edition by Matthew L Carlson (Editor), Michael J. Link (Editor), Colin L.W. Driscoll (Editor)

List Price: $175.49

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The definitive resource on clinical management of vestibular schwannoma from world renowned experts

Although a histologically benign and relatively uncommon tumor, otolaryngologists and neurosurgeons have maintained a lasting and deep-rooted fascination with vestibular schwannoma, also known as acoustic neuroma. Advancements in microsurgical technique, radiosurgery, and radiotherapy, coupled with an increased understanding of the natural history of the disease, have made modern management of this tumor considerably more complex. Concurrently, new controversies have added to the original debates among pioneering surgeons, with the pendulum swinging between conservatism and definitive cure.

Comprehensive Management of Vestibular Schwannoma, by distinguished Mayo Clinic clinicians and renowned international contributors, is a comprehensive textbook covering all the clinical aspects of vestibular schwannoma management. Eighty-four chapters written by multidisciplinary experts including otolaryngologists, neurosurgeons, radiation oncologists, neurologists, neuroradiologists, and audiologists, ensure a balanced view of all treatment modalities for sporadic and neurofibromatosis type 2-associated vestibular schwannoma.

Key Features

Evaluation, surgical and nonsurgical approaches, rehabilitation, controversies, and long-term clinical outcomes Detailed illustrations by Robert Morreale, senior medical illustrator at the Mayo Clinic, highlight relevant anatomy and surgical approaches Chapter summary tables provide readers with a rapid clinical reference derived from the published world literature The chapter “Anatomy of Vestibular Schwannoma Surgery” by the late internationally renowned neurosurgeon Albert L. Rhoton Jr. reflects his major contributions on this subject With inclusion of fundamental principles to advanced concepts, this is a robust resource for residents, fellows, and early attending physicians, as well as mid- to later-career physicians who care for patients with vestibular schwannoma.

This book includes complimentary access to a digital copy on https://medone.thieme.com.

Retrosigmoid transmeatal approach for vestibular schwannoma videos

Retrosigmoid transmeatal approach for vestibular schwannoma videos

Dorsal displacement of the facial nerve is relatively rare in patients with vestibular schwannoma. Its prediction remains difficult in patients with large tumors, even with the recent advances in preoperative radiologic assessments. Anatomic and functional preservation of the facial nerves combined with maximal tumor removal is particularly challenging in this rare anatomic variant, and surgery may lead to postoperative facial nerve paralysis, inadequate tumor removal, and/or a high retreatment rate.

The 3-dimensional video (Video 1) demonstrates a vestibular schwannoma with dorsally displaced facial nerve, which was surgically treated by the retrosigmoid transmeatal approach under continuous facial nerve monitoring. The video was reproduced after informed consent of the patient. A 46-year-old man presented with transient hearing impairmentNeuroimaging displayed a left vestibular schwannoma extending into the internal acoustic meatus. The retrosigmoid transmeatal approach was performed, and a dorsally displaced facial nerve was predicted by preoperative magnetic resonance images and confirmed during surgery. The facial nerve was accurately dissected under continuous facial nerve monitoring, and gross total resection of the tumor was achieved without postoperative facial dysfunction 1).


A case of a mid-sized vestibular schwannoma (T3b according to the Hannover Grading Scale) that was resected through a Endoscopic assisted retrosigmoid approach in semisitting position

A 52-year-old male with acute loss of functional hearing on the right side. Audiometry confirmed a loss of up to 60 dB and lost speech discrimination, there were no associated symptoms such as tinnitus or vertigo. This 2D video demonstrates positioning, OR set-up, anatomical and surgical nuances of the skull base approach and the operative technique for microdissection of the tumor from the critical neurovascular structures, especially the facial and cochlear nerves. A gross total resection was achieved and the patient discharged home after four days with unaltered function of the facial nerve (HB I). At one year follow up there was no indication of residual or recurrence. In summary, the retrosigmoid transmeatal approach is an important and powerful tool in the armamentarium for the microsurgical management of all kinds of vestibular schwannomas. Provided the necessary anesthesiological precautions and intraoperative procedures the semi-sitting position is safe and effective. If needed, the approach can be complemented by the use of an endoscope for visualization of the distal internal auditory canal. The link to the video can be found at: https://youtu.be/pPKT4_5nIn0 2).


The anterior inferior cerebellar artery (AICA) usually runs loosely within the cerebellopontine cistern; in rare cases, however, it is firmly adherent to the petrous dura mater. Recognizing this variation is particularly important in vestibular schwannoma surgery via the retrosigmoid transmeatal approach to prevent the high morbidity associated with vascular injury. This video demonstrates a surgical technique to effectively mobilize the AICA when firmly adherent to the petrous dura mater.

A 39-year-old man presented with a history of progressive right-sided hearing loss without facial weakness or other associated symptoms. Magnetic resonance imaging (MRI) demonstrated an intracanalicular lesion, suggestive of vestibular schwannoma. During follow-up, audiometryconfirmed a further slight deterioration of hearing and repeated MRI demonstrated tumor growth (T2 according to Hannover Grading Scale). Since the patient opted against radiosurgery, a retrosigmoid transmeatal approach under continuous intraoperative monitoring was performed in supine position. Following drainage of cerebrospinal fluid and exposure of the cerebellopontine cistern, the AICA was found to be firmly adherent to the petrous dura mater. Both structures were elevated conjointly and displaced medially for safe drilling of the inner auditory canal, sufficient exposure, and complete excision of the vestibular schwannoma. The patient had an excellent recovery, hearing and facial function were preserved, and no secondary neurological deficits noted.The patient consented to publication of this anonymized video 3).


Skull Base Neurosurgery – University of Colorado


George Kaptain


Paolo Regolo


Sameer A. Sheth

References

1)

Matsushima K, Kohno M, Nakajima N, Ichimasu N. Dorsally Displaced Facial Nerve in Retrosigmoid Transmeatal Approach for Vestibular Schwannoma: 3-Dimensional Operative Video. World Neurosurg. 2019 Mar;123:300. doi: 10.1016/j.wneu.2018.11.261. Epub 2018 Dec 21. PubMed PMID: 30580063.
2)

Evangelista-Zamora R, Lieber S, Ebner FH, Tatagiba M. Retrosigmoid Transmeatal Endoscope-Assisted Approach in Semi-Sitting Position for Resection of Vestibular Schwannoma: 2-D operative Video. J Neurol Surg B Skull Base. 2018 Dec;79(Suppl 5):S385-S386. doi: 10.1055/s-0038-1669985. Epub 2018 Oct 9. PubMed PMID: 30473983; PubMed Central PMCID: PMC6240135.
3)

Tatagiba MS, Evangelista-Zamora R, Lieber S. Mobilization of the Anterior Inferior Cerebellar Artery When Firmly Adherent to the Petrous Dura Mater-A Technical Nuance in Retromastoid Transmeatal Vestibular Schwannoma Surgery: 3-Dimensional Operative Video. Oper Neurosurg (Hagerstown). 2018 Nov 1;15(5):E58-E59. doi: 10.1093/ons/opy052. PubMed PMID: 29617908.
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