Cervical Neurinoma Encasing Vertebral Artery

Case Report Cervical Neurinoma Encasing Vertebral Artery: a case report and review of the literature Afsoun Seddighi, Amir Saied Seddighi, Maryam Sadegh Azar, Amir Hossein Zohreh Vand Functional Neurosurgery Research Center, Shohada Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran ABSTRACT Our case was a 48-year-old man with cervical pain radiating to the upper limbs. Imaging showed an intradural tumor with extradural component encasing the vertebral artery. The tumor diagnosed as a neurinomaand had been removed surgically. The post operation magnetic resonance imaging showed that the tumor was completely removed and the vertebral artery was intact at the entire length. The goal of surgery of neurinoma is a total removal of the tumor, however if the vertebral artery is completely encasing by the tumor, it is advisable to remove the tumor to the level that the vertebral intactness is saved. Keywords: Neurinoma; Cervical; Vertebral artery ICNSJ 2014; 1 (2):65-68 www.journals.sbmu.ac.ir/neuroscience Correspondence to: Amir Saied Seddighi, MD; Functional Neurosurgery Research Center, Shohada Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; E-mail: [email protected]; Tel: +98(912)2151591 Received: July, 24, 2014 Accepted: October, 19, 2014 INTRODUCTION Cranial neurinomas are benign and relatively slow growing tumors, but growing in unusual sites can cause several clinical manifestations by compressing surrounded neurovascular structures1. About 25%-40% of the schwannomas are in the head and neck region2. Extradural component of this tumor is located in the mediastinum or pre vertebral areas, and the expatiation of this component make neurinoma as one of most common tumors causing medullary compression at the cervical level3. Extradural and extra spinal extension occurs in about 15% of this tumors4. Complete removal of these tumors can cause a series of problems in nerve root preservation and saving the stability of the spine and the vertebral artery and can lead to fatal out comes5. Preoperative vertebral angiography should be performed to identify the compromising of the vertebral artery by a cervical neurinoma6. The resection of the tumor can be done by aposterior, anterolateral, anterior approach based on the location, size and the involved area4. Mainly the posterior surgical approach to cervical cord tumors is preferred, with favorable post-operative results 7. Recurrences of these tumors after total removal are rare2. CASE PRESENTATION A 48-year-old male was admitted to the hospital with pain over the neck, left shoulder and arm. Neurological examination revealed left-sided spastic hemiparesis, more pronounced distally hypoesthesia below C2 dermatome and hyperactive deep tendon reflexes. T1-weighted Magnetic resonance imaging (MRI) of the cervical spine showed a hypointense mass measuring 1.5x2x2.5 cm and occupying the left neural foramen and left half of the spinal canal. The lesion had a prominent hyperintense center with a hypointense periphery on T2-weighted images. There was a marked contrast enhancement of the periphery of the lesion following gadolinium injection (Figure 1). Intradural component of the mass was showed compression on the left side of the spinal cord while the extradural component was close to the vertebral artery. Cranial diffusion perfusion MRI performed to depict cerebral vascularization and collateral circulation was normal (Figure 2). International Clinical Neuroscience Journal • Vol 1, No 2, Autumn 2014 65 Cervical Neurinoma Encasing Vertebral Artery—Seddighi et al Figure 2. Axial T1 weighted MRI which shows left sided neurinoma. Figure 1. MRI of the cervical spine of our patient showing C2 Neurinoma. Vertebral MR angiography was performed to determine the course of the vertebral artery and to plan the surgical procedure (Figure 3). The patient was operated via a post exposure with cervical laminectomy. The tumor was considered as a neurofibroma, there were possibilities of spinal cord compression by the intradural component and adhesions of the extradural component to the vertebral artery and venous structures around it (Figure 4). Majority of the nerve fibers are entrapped within tumoral tissue in dumbbell neurofibroma cases, as in our case. It is impossible to remove the tumor without sacrificing the nerve root and aggressive surgery that may result in severe neurological deficits. Partial resection in dumbbell neurofibroma cases is safer but there is always the risk for recurrence and reoperation may be more hazardous. Since we predicted the encasement of the vertebral artery, we asked a vascular surgeon to collaborate. To remove the parts of the tumor that were attached to the vertebral artery proximal, ligation was performed and after complete resection of the tumor, vertebral Figure 3. Preoperative MR angiography which shows patent vertebral arteries. 66 International Clinical Neuroscience Journal • Vol 1, No 2, Autumn 2014 Cervical Neurinoma Encasing Vertebral Artery—Seddighi et al Figure 4. Intraoperative view shows the gross tumor bulk. artery reconstruction was done. Post operation MRI and angiography was performed for fallow up of the patient showed no visible damage to the artery (Figure 5, Figure 6). There was no recurrence of the symptoms at one year follow up. DISCUSSION Dumbbell- shaped neurinomas constitute 6% of all spinal tumors. In the cervical region 71% of the tumors are dumbbell shaped. Mainly the spinal neurinomas are intradural benign tumors, with a slow growth and an occurrence of 43.3% to 58.3% in the cervical region3. The extradural and intardual expansion of this tumor can lead to compressions of the spinal cord and the close vascular systems that make the preoperative imaging Figure 6. Post-operative angiography showed a complete preservation of the vertebral artery. evaluation of the tumor advisable to distinguish the location and origin of the tumor8. A total removal of the tumor without any complication can be challenging due to the location combined with the close anatomical relation of the tumor to important vascular and nervous structures. Partial resection in dumbbell neurofibromaisis safer but the risk for recurrence and the need of reoperation may be more hazardous. A total resection usually had a good long-term outcome with low recurrence risk. Although the involvement of the vertebral artery from both sides make the resection of tumor complicated. The resection Figure 5. Post-operative MRI with contrast shows complete tumor removal. International Clinical Neuroscience Journal • Vol 1, No 2, Autumn 2014 67 Cervical Neurinoma Encasing Vertebral Artery—Seddighi et al of the tumor can be done by aposterior, anterolateral, anterior approach based on the location, size and the involved area4. The anterior or anterolateral approach has several advantages like safe separation of the tumor from the vertebral artery due to the direct visualization of the vertebral artery. It also had a low risk of injuring the spinal cord by removing of the extra spinal canal tumors9. Overall, the posterior approach for cervical cord tumors is preferred. This approach is useful in intraspinal canal tumors, but the extraspinal canal tumors are relatively inaccessible by this approach3. In the literatures the modified posterior approach had showed the advantages to be a less invasive method to the cervical vertebrae and due to that, the occurrence of postoperative instability and angular deformity, and long postoperative immobilization had been reduced7. However an angiography is needed to identify the diameter and involvement of the vertebral artery before the operation, to avoid complication due to the ligation of the vertebral artery if it is necessary. In such cases the diameter of the ligated vertebral artery should not be larger than the not involved one10. The approaching method should be chosen by including all the important factors such as location, size and the involved of the area by the tumor, to prevent further surgical interventions. To avoid incomplete resection or the involvement of nerve or vascular systems by the removing of the tumor, consulting should be done before and at the time of surgery. of the tumor with adequate spinal cord decompression can be preferred to prevent vertebral artery injury. CONCLUSION The most significant feature of dumbbell neurofibromas is the adhesion of the tumor to the environment by enlarging the foramen and projecting outward from the spinal canal. The goal of surgery is total removal of the tumor. Although a variety of surgical approaches for these lesions is available, most cervical spine dumbbell tumors can be effectively managed with a single-stage posterior exposure with partial laminectomy and unilateral facetectomy. However, in selected cases partial removal 8. Righini CA, Motto E, Faure C, Karkas A, Lefournier V, Reyt E. [Schwannomas of the neck. About 3 cases, and literature review]. 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