Schwannoma of the spinal accessory nerve in the cisterna magna

Neoplasm

Schwannoma of the Spinal Accessory Nerve in the Cisterna Magna Kyoko Tatebayashi, M.D.,* Yasuakira Tanaka, M.D.,† Hideharu Numata, M.D.,† Shin Kawakami, M.D.,† Hideki Kamitani, M.D.,* and Takashi Watanabe, M.D.* *Department of Neurosurgery, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, and †Department of Neurosurgery, San-in Rosai Hospital, Yonago, Tottori, Japan

Tatebayashi K, Tanaka Y, Numata H, Kawakami S, Kamitani H, Watanabe T. Schwannoma of the spinal accessory nerve in the cisterna magna. Surg Neurol 2003;59:217–22. BACKGROUND

Intracranial schwannoma of the accessory nerve can be divided into two types. One is a jugular foramen type arising from the accessory nerve of the jugular foramen, while the other is an intracisternal type, which arises from the spinal root of the accessory nerve and is separate from the jugular foramen. The latter type is rare, and only 9 cases have been reported previously. CASE DESCRIPTION

A 46-year-old female presented with a large, midline mass lesion in the posterior fossa manifesting as foramen magnum syndrome. Magnetic resonance imaging (MRI) revealed a huge tumor with cystic lesion located in the cisterna magna with extension to the C1 spinal level. The tumor was totally removed by a suboccipital craniectomy and C1 laminectomy. It originated from the spinal root of the right accessory nerve. Temporary slight atrophy of the right sternocleidomastoid muscle was observed, but the patient was free of disease 2 years after treatment. CONCLUSIONS

We report a schwannoma of the spinal accessory nerve in the cisterna magna. The clinical and neuroradiological findings are discussed with a review of the literature. The initial symptoms were variable without loss of function of the cranial nerve, and the tumor tended to grow in the cisterna magna without laterality. Because of the absence of typical neurologic symptoms, early neuroradiological investigation by MRI is recommended for accurate diagnosis of these tumors. © 2003 Elsevier Science Inc. KEY WORDS

Spinal accessory nerve schwannoma, intracisternal type, foramen magnum syndrome, cisterna magna.

Address reprint requests to: Kyoko Tatebayashi, Department of Neurosurgery, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504, Japan. Received January 18, 2002; accepted August 8, 2002. © 2003 by Elsevier Science Inc. 360 Park Avenue South, New York, NY 10010 –1710

he great majority of intracranial schwannomas arise from the acoustic nerve. Schwannoma arising from other cranial nerves are uncommon. According to a review of uncommon schwannomas, the incidence of schwannomas arising from the trigeminal nerve, the facial nerve, and the lower cranial nerves are 40, 23, and 20%, respectively [11,20]. The lower cranial nerves, including the glossopharyngeal nerve, the vagus nerve, and the accessory nerve, form a complex at the jugular foramen. Therefore, a lower cranial schwannoma at the jugular foramen is generally defined as a jugular foramen schwannoma without identification of the individual cranial nerves. On the other hand, the accessory nerve consists of two portions: the cranial root and the spinal root. The cranial root of the accessory nerve combines with the vagus nerve, and it is difficult to recognize at this location. Based on anatomy, intracranial accessory nerve schwannomas can be divided into two types [7]; the jugular foramen type, which is the majority of cases, and the intracisternal type, which occupies the cisterna magna. We report a rare case of a spinal accessory nerve schwannoma in the cisterna magna, and discuss the clinical and radiologic features of the tumor based on the published literature.

T

Case Report A 46-year-old female was admitted to the San-in Rosai Hospital in October 1999 complaining of headache along with intermittent nausea and vomiting. One year before admission, she had complained of headache and dull aching pain in her shoulder and neck. These symptoms worsened 0090-3019/03/$–see front matter doi:10.1016/S0090-3019(02)01035-2

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Preoperative magnetic resonance imaging: T1-weighted axial image revealed a low intensity mass with clear periphery and a funicular structure on its inside (A). The contrast-enhanced T1-weighted axial (B) and sagittal (C) images showed the peripheral wall and the internal tubercle of the mass was well enhanced, extending from the cisterna magna to the C1 level and severely compressing the medulla oblongata.

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over the next 6 months and she began to feel numbness in her right upper limb. Medication for headache and her shoulder stiffness had no effect. On admission, neurologic examination revealed horizontal nystagmus, dysmetria of her right upper limb, cold dysesthesia in her right upper limb, and hypesthesia in her right lower limb. No pyramidal tract disturbance was found. Hearing test and auditory brainstem response were normal, but equilibrium test indicated a mild right brainstem dysfunction. Computed tomography scan demonstrated a lowdensity mass in the posterior fossa. Magnetic resonance imaging (MRI) revealed a huge tumor, 3.5 ⫻ 4.5 ⫻ 4.0 cm, extending from the cisterna magna to the C1 level and severely compressing the medulla oblongata. The ventricular system was enlarged. The lesion, which had a clear margin showed heterogeneous low intensity and a funicular structure on its inside on T1-weighted image, and almost uniformed high intensity on T2-weighted images. After IV administration of contrast medium, the peripheral wall and the internal tubercle of the mass were well enhanced (Figure 1). Left vertebral angiogram showed that the posterior medullary segment and supra-tonsillar segment of the left posterior inferior cerebellar artery and the right anterior inferior cerebellar artery were displaced outwards. No tumor stain was observed (Figure 2). A week after admission, the tumor was removed via a suboccipital craniectomy and C1 laminec-

tomy. At the opening of the dura mater, a yellowish, and rhomboid-shaped tumor was visible with faint vascularization on the surface. The tumor displaced

Left vertebral artery angiogram, anterior-posterior view. The medullary segment and supra-tonsilar segment of the left posterior inferior cerebellar artery and the right anterior inferior cerebellar artery were displaced outwards. No tumor stain was observed.

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Operative photographs: a yellowish, rhomboid-shaped tumor was visible with faint vascularization on the surface. The tumor displaced both tonsils upward with extension to the C1 level of the spinal cord. It consisted of a solid region in the main upper portion and included some cysts in the lower portion (A). The spinal accessory nerve spread and adhered to the tumor capsule, and it was impossible to distinguish the bundle of the nerve from the capsule (B).

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both tonsils upward with extension to the C1 level of the spinal cord. It consisted of solid region in the main upper portion and contained some cysts in

the lower portion (Figure 3A). It originated from the spinal root of the right accessory nerve, and resembled a hump of the nerve. The nerve spread and

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Postoperative contrast-enhanced sagittal MRI: the tumor was removed and the medulla oblongata released from the compression.

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adhered to the tumor capsule, and it was impossible to distinguish the bundle of the nerve from the capsule (Figure 3B). The other lower cranial nerves in the jugular foramen were normal. The right spinal accessory nerve was severed at the origin of the tumor, which was totally removed. Pathology revealed a typical schwannoma, containing both Antoni type A and B cells. After the operation, her headache disappeared, but the hypesthesia in her right upper limb was still present. She recovered and showed no impairment of neck motion. Postoperative MRI confirmed the complete removal of the lesion and that the medulla oblongata was released from the compression (Figure 4). During the following 2 years, temporary slight atrophy of the right sternocleidomastoid muscle was noticed. There has been no clinical recurrence.

Discussion Intracranial schwannoma of the spinal accessory nerve is rare. In a review of the literature, we found 28 cases of accessory nerve schwannomas [1,5,6,8,9,13,16,19,23]. Julow [7] categorized these tumors into two types based on the location of the tumor: an intrajugular type located at the jugular foramen and an intracisternal type located at the

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cisterna magna. He reported 2 cases of the latter type. Since Christoferson et al [3] first reported a schwannoma of the intracisternal type, only 9 cases have been recorded. In addition to our case, these reported cases of spinal accessory nerve schwannoma in the cisterna magna are summarized in Table 1. Initial complaints and symptoms such as headache, nausea, dizziness, motor weakness, dysesthesia, neck stiffness, and dullness were observed in each case. These symptoms were slowly progressive, with additional symptoms, such as hemiparesis, cerebellar signs, accessory nerve palsy, hydrocephalus, dysesthesia, and myelopathy observed. In almost all cases, accessory nerve disturbance was not clearly observed, as it resembles foramen magnum syndrome [24]. It took on average 27.3 months after the onset for an accurate diagnosis, as with foramen magnum tumors. On imaging we found three interesting points. Firstly, 9 of the 10 spinal accessory nerve schwannomas were located at the midline region in the posterior fossa, despite the fact that the tumor originated far from the midline. We speculate that the cisterna magna has sufficient space to allow extension of rather soft tumors with multiple cysts. This observation of the tumor in the midline region made a preoperative diagnosis difficult. Secondly, as cystic degeneration is a well-known phenomenon in acoustic schwannomas, these tumors showed cyst formation in 6 of 10 cases, and 5 of these cases were described as being composed of multiple cysts. Thirdly, although schwannomas show tumor stains on 12⬃62% of angiograms [4,10,15,17,18,22], none of the 8 spinal accessory nerve schwannomas demonstrated tumor stains. Regarding the treatment for these tumors, in 7 of the 10 cases of spinal accessory nerve schwannomas, total removal was performed via a suboccipital craniectomy with or without upper cervical laminectomy, and none of the 10 cases developed recurrence. An accessory nerve disturbance appeared in 4 of 10 cases after operation. Hydrocephalus was observed in 4 cases. A ventriculoperitoneal (VP) shunt was placed before resection of the tumor in 2 cases [16,21]. In the other 2 cases (12, present case), a VP shunt was not required because the cerebrospinal fluid route was patent after resection of the tumor. In conclusion, we present a rare case of an intracranial schwannoma of the spinal accessory nerve in the cisterna magna with a review of the literature. Intracranial schwannoma of the spinal accessory nerve mainly tend to grow in the cisterna magna by

Summary of Spinal Accessory Nerve Schwannomas in the Cisterna Magna

AUTHOR, YEAR

AGE & SEX

TIME

TO DIAG.

Christoferson 24 F 1 year et al, 1982 [3] Julow, 1983 50 F 10 years [7] Julow, 1983 29 M 4 years [7] Nishiura et 52 M al, 1984 [14] Chang et al, 32 M 1990 [2] Lanotte et al, 62 M 1994 [12]

5 years

Soo et al, 1995 [21] Ohkawa et al, 1996 [16] Caputi et al, 1997 [1] Present case, 1999

54 F

7 months

54 F

7 months

42 M

1 month

46 F

1 year

3 months 3 months

ONSET Increasing weakness of the left leg

CLINICAL SYMPTOMS

TUMOR STAIN

TREATMENT/ COMPLICATION*

Midline

Resection/⫹⫹

—

4 ⫻ 3 ⫻ 4/⫹

Midline

Total removal/⫺

Unknown

Unknown/ unknown

Midline

Total removal/⫺

—

Unknown/ unknown

Midline

Total removal/⫹

—

4 ⫻ 4 ⫻ 2.5/⫹

Midline

Total removal/⫹⫹

3.6 ⫻ 2.6 ⫻ 2.4/⫺

Right

Total removal/⫹⫹

Unknown/⫹

Midline

Unknown/⫹

Midline

2.2 ⫻ 1 ⫻ 1.3/⫹

Midline

VP shunt, partial resection/⫺ VP shunt, resection/⫺ Total removal/⫺

Midline

Total removal/⫹⫹

Unknown

Right accessory nerve palsy, left dysmetria Burning sensation on Atrophy of muscles right forearm controlled by accessory nerve Intermittent occipital R. cerebellar signs headache, vomiting Mild headache, L. cerebellar signs, vertigo, nausea, NPH unsteady gait Headache nausea Cerebellar signs, hydrocephalus Headache nausea R. cerebellar signs hydrocephalus Neck pain with SAH muscle spasm Headache, shoulder R. cerebellar signs, and neck dullness sensory disturbance hydrocephalus

Slight progressive tetraparesis

SIZE (CM)/CYST LOCATION 3.5 ⫻ 3.0 ⫻ 2.5/⫺

Atrophy, weakness and spasticity of the left leg Myelopathy, IICP

Headache

MRI FINDINGS

— — — — —

T1 low-iso, T2 high well enhanced T1 low, T2 high lobular CE T1 low, T2 high enhanced T2 low

T1 low, T2 high 3.5 ⫻ 4.5 ⫻ 4.0/⫹ well enhanced

Surg Neurol 221 2003;59:217–22

diag. ⫽ diagnosis, *complication; accessory nerve disturbance, ⫹; stable, ⫹⫹; symptoms appeared after operation. R. ⫽ right, L. ⫽ left, NPH ⫽ normal pressure hydrocephalus, SAH ⫽ subarachnoid hemorrhage, IICP ⫽ increased intracranial pressure, T1 ⫽ T1 weighted image, T2 ⫽ T2 weighted image, low ⫽ low intensity, iso ⫽ iso intensity, high ⫽ high intensity, CE ⫽ contrast enhancement, VP shunt ⫽ ventriculoperitoneal shunt.

Spinal Accessory Nerve Schwannoma

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formation of multiple cysts. Because of the absence of typical neurologic symptoms, early neuroradiological investigation by MRI is recommended for an accurate diagnosis of these tumors.

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15.

16.

REFERENCES 1. Caputi F, Sanctis S, Gazzeri G, Gazzeri R. Neuroma of the spinal accessory nerve disclosed by a subarachnoid hemorrhage: case report. Neurosurgery 1997;41: 946 –50. 2. Chang KC, Huang JS, Liu KN, Tsai CS, Chen TY. Neurinoma of the spinal accessory nerve: report of a case. J Formosan Med Assoc 1990;89:593–7. 3. Christoferson LA, Leech RW, Grossman M. Intracranial neurilemoma of the spinal accessory nerve. Surg Neurol 1982;18:18 –20. 4. Dechaume JP, Bochu M, Michel D, Joyeux O, Bret Ph, Barbeau P. Pathological tumour circulation—a study of 50 cases by retrograde brachial vertebral angiography. Neuroradiology 1970;1:151–4. 5. Hakuba A, Hashi K, Fujitani K, Ikuno H, Nakamura T, Inoue Y. Jugular foramen neurinomas. Surg. Neurol 1979;11:83–94. 6. Iwasaki K, Kondo A. Accessory nerve neurinoma manifesting with typical jugular foramen syndrome. Neurosurgery 1991;29:455–9. 7. Julow J. Neurinoma of spinal accessory nerve: report of two cases. Acta Neurochirurgica (Wien) 1983;69: 219 –24. 8. Kawaguchi S, Ohnishi H, Yuasa T, Hashimoto H. Spinal accessory nerve neurinoma in the C2 spinal canal: case report. Neurol Med Chir (Tokyo) 1987;27: 1190 –4. 9. Kaynar MY, Hanci M, Sarioglu AC. Intraspinal schwannoma of the accessory nerve. Br J Neuorsurg (US) 1999;13(4):429 –31. 10. Kendall B, Symon L. Investigation of patients presenting with cerebellopontine angle syndromes. Neuroradiology 1977;13:65–84. 11. Khang-Loon Ho. Schwannoma of the trochlear nerve: case report. J Neurosurg 1981;55:132–5. 12. Lanotte M, Massaro F, Scienza R, Faccani G. Intracisternal schwannoma of the spinal accessory nerve presenting as a normal pressure hydrocephalus syndrome. Case report and review of the literature. Neurosurg Rev 1994;17:225–7. 13. Matsushima T, Fukui M, Matsunaga M, Kitamura K, Hasuo K. Accessory nerve neurinoma mimicking a brain stem tumor on angiography: report of a case. Neurosurgery 1985;16:839 –42. 14. Nishiura I, Koyama T. Neurinoma of the spinal acces-

17. 18.

19.

20. 21. 22. 23. 24.

sory nerve: a case report. Neurochirurgia 1984;27: 154 –7. Numaguchi Y, Kishikawa T, Ikeda J, et al. Angiographic diagnosis of acoustic neurinomas and meningiomas in the cerebellopontine angle—a reappraisal. Neuroradiology 1980;19:73–80. Ohkawa M, Fujiwara N, Takashima H, et al. Radiologic manifestation of spinal accessory neurinoma: a case report. Radiat Med 1996;14:269 –73. Perneczky A. Blood supply of acoustic neurinomas. Acta Neurochirurgica 1980;52:209 –18. Dubois PJ, Drayer BP, Bank WO, Deeb ZL, Rosenbaum AE. An evaluation of current diagnostic radiologic modalities in the investigation of acoustic neurilemmomas 1. Neuroradiology 1978;126:173–9. Pluchino F, Crivelli G, Vaghi MA. Intracranial neurinomas of the nerves of the jugular foramen: report of 12 personal cases. Acta Neurochirurgica (Wien) 1975;31: 201–21. Samii M, Migliori MM, Tatagiba M, Babu R. Surgical treatment of trigeminal schwannomas. J Neurosurg 1995;82:711–8. Soo SJ, Irie K, Fujiwara T, Kuyama H, Nagao S. A case of accessory nerve neurinoma presenting an intracisternal tumor. No Shinkei Geka (Jpn) 1995;23:723–6. Takahashi M, Okudera T, Tomanaga M, Kitamura K. Angiographic diagnosis of acoustic neurinomas: analysis of 30 lesions. Neuroradiology 1971;2:191–200. Tsuchiya K, Machida T, Maehara T, Iio M. A case of accessory nerve neurinoma. Rinsho Houshasen (Jpn) 1982;27:1375–8. Yasuoka S, Takakura K. Proposal for the definition of “Foramen magnum syndrome.” No Shinkei (Jpn) 1983; 35(10):1001–7.

COMMENTARY

This is a straightforward case report of an extremely rare tumor, the intracisternal spinal accessory nerve schwannoma. It is accompanied by a quite instructive table summarizing in significant detail the prior 9 reports in the literature, each of which have been reports of single cases, which further attests to their rarity. The authors do not mention one other rare schwannoma in this region, hypoglossal schwannoma, of which I have seen only one case (unreported). Leonard I. Malis, M.D. Neurosurgeon New York, New York