Delayed Manifestation of Sacral Clear Cell Meningioma Distent Metastasis or Multifocal Disease?

doi:10.4236/ss.2011.26064

Paper Menu >>

Journal Menu >>

Surgical Science, 2011, 2, 297-302

doi:10.4236/ss.2011.26064 Published Online August 2011 (http://www.SciRP.org/journal/ss)

Delayed Manifestation of Sacral Clear Cell

Meningioma Distent Metastasis or

Multifocal Disease?

Habib Nouri1, Leila Abid2, Moez Ouertatani1, Dalenda Hentati3, Mondher Mestiri2, Habib Jaafoura2

1Department of “Adult” Surgery, Kassab’s Institute, Tunisia

2Department of “Pathology”, Kassab’s Institute, Tunisia

3Department of Radiat i o n Therapy, National Institute of Oncology, Tunisia

E-mail: [email protected]

Received December 6, 2010; revised December 26, 2010; accepted January 13, 2011

Abstract

Study Design: the authors report on a clear cell meningioma (CCM) of the sacrum revealed 17 years after a

removal of a spinal lesion. A review of 29 spinal CCM previously reported was done. Objective: To focus on

clinical and biological behaviour of CCM. Summary of Background Data: CCM is a rare subtype charac-

terrized by its inordinately aggressive clinical course despite its benign appearance. The tumour shows pro-

clivity for the cerebellopontine angle and cauda equine region. Recurrence and metastasis have been com-

monly reported. Method: a 26 year-old man presented with low back pain related to a lytic lesion of the sa-

crum. He had a history of an intradural extramedullary meningioma of the cervical spine removed when he

was 9 year-old. CT scan revealed a sacral osteolytic lesion with anterior and lateral extension. Open biopsy

revealed a clear cell meningioma. That was the same pattern of the tumour removed 17 years before. Results:

Our patient was managed conservatively by palliative radiation therapy. At 2 years follow-up, he experi-

enced improvement of pain and walking. Conclusion: CCM is an aggressive tumour with a high risk of me-

tastases through cerebrospinal fluid. A follow up with spinal MRI should be performed.

Keywords: Clear Cell Meningioma, Spine, Cerebrospinal Fluid, Metastasis, Local Recurrence, Radiation

Therapy, Pathology

1. Introduction

Meningiomas are the most common primary tumours of

the central nervous system. Approximately 90% to 95%

of them are classified as grade I according to the World

Health Organization (WHO) 2007 criteria [1], whereas 5

to 7% are graded II and 1 to 2.8% are graded III. Clear

cell meningiomas (CCM) are rare and have been re-

ported in only 0.2% of cases [2]. They are graded II or

aggressive. The tumour shows proclivity for the cere-

bellopontine angle and cauda equine region. Despite its

benign appearance, CCM has an aggressive behaviour

and recurrence and metastasis has been commonly re-

ported.

Here we report an unusual case of a metastatic clear

cell meningioma to the sacrum, discovered 17 years after

total resection of the primary cervical lesion. The clinical

and pathological features are discussed.

2. Case Report

A 26 year-old male was referred to our department in

2007 for a tumour of the sacrum. He underwent in 1990

when he was 9 year-old a resection of an intraspinal tu-

mour. Cervical CT scan had revealed an intraduralex-

tramedullary tumor measuring 2 cm at the level of C4-C5.

The tumor was well-circumscribed, homogeneous, lo-

cated posteriorly, and compressing the spinal cord. The

tumor was excised totally. Pathological examination had

revealed a particular meningioma characterized by the

presence of mycrocystic cells and prominent interstitial

collagen which separate or enclose the cellular aggre-

gates. A Masson’s trichrome stain highlighted the abun-

dant collagen component. The neoplastic cells were ar-

ranged in sheets and forming a rare whorls. The stromal

blood vessels have a thick hyalinized wall. The patient

got no further therapy and follow-up was uneventful for

H. NOURI ET AL.

298

17 years.

His complaints were progressive sacral pain and con-

stipation. There was neither mass nor neurological deficit

in clinical findings.

Plain radiographs showed a radiolucent expansion of

the sacrum (Figure 1). Pelvic CT scan revealed a huge

mass involving the entire sacrum, expanding anteriorly

and invading the ilio-sacral joints (Figures 2(a) and (b)).

Cervical spinal CT scan didn’t show any local recurrence

of the primary lesion.

An open biopsy in the sacrum was performed. His-

tologically, the tumour was composed of sheets of po-

lygonal cells with clear cytoplasm and prominent inter-

stitial collagen (Figure 3(a)). Neoplastic cells had ve-

sicular, round to oval nuclei and small nucleoli. There

was no significant cytological atypia or pleomorphism.

No mitotic figures were identified (Figure 3(b)). The

cells have an abundant clear cytoplasm PAS-positive due

to glycogen accumulation. In particular, there were nu-

merous concentrically laminated eosinophilic, colla-

genous structures intersecting throughout the lesion.

However, typical psammoma bodies were not seen. Only,

a few vague whorls were seen. Extensive immunohisto-

chemistry has been performed. The neoplastic cells

stained strongly diffuse positivity for vimentin. The tu-

mor cells were also positive for EMA and S100. Moder-

ate positivity was demonstrated with progesterone re-

ceptor (Figure 3(c)). The cells showed negative staining

with cytokeratin, chromogranine and glial fibrillary pro-

tein. The reactivity of the tumor cells with the antibody

MIB-1 showed a very low labelling index and the per-

centage of cells that expressed MIB-1 was about 1%.

On the basis of these histological findings, the diagno-

sis was that of clear cell meningioma. Primary histologi-

cal specimens taken at the age of 9 years were available

for study and showed the same features of the sacral tu-

Figure 1. P lain radiographe AP view showing a radiolucent

expension of the sacrum.

(a)

(b)

Figure 2. CT scan of the pelvis. (a) axial view showing an

osteolytic lesion of the sacrum invading the intrapelvic or-

gans anteriorly and the ilio-sacral joints laterally; (b) sagit-

tal reconstruction. The tumor mass invaded the spinal canal

and the presacral space. Note that posterior extension is

limited.

mour. Therefore we concluded to an osseous metastatic

clear cell meningioama. Chest CT scan was negative. The

patient received palliative radiation therapy consisting of

6000 cGy delivered in 30 fractions. Four years later, he

was still alive, he experienced improvement of pain. The

mass was stable on control CT scan (Figure 4).

3. Discussion

Our case with primary extracranial CCM and the so far

metastasis to the sacrum is unique. It presented mainly 2

H. NOURI ET AL.299

(a)

(b)

(c)

Figure 3. (a) Microscopically, the tumour is composed of

patternless sheets of clear-cells in a collagen background

(Hematoxylin and eosin, original magnification × 200); (b)

neoplastic cells had vesicular, round to oval nuclei and

small nucleoli. The cells have an abundant clear cytoplasm

PAS-positive; (c) tumour cells show a moderate immuno-

reactivity for progesterone receptor.

Figure 4. CT scan 4 years later. The mass is stable.

problems, a therapeutic one characterised by the absence

of a consensus in literature. Secondly, the relationship

between the present tumor and the primary cervical le-

sion remains unclear.

Clear cell meningioma is perhaps the rarest of the tu-

mors of meningothelial origin. Among 485 cases, K-W

ko et al. [3] found 3 CCMs (0.6%). Zorludemir et al. [2]

reported the largest series of 13 cases of CCM. The most

frequent site of involvement was the spinal intradural

region (56%). Twenty nine documented cases of spinal

CCMs reported previously were found from literature

[2,4-24]. Clinical data and outcome are summarised in

the Table 1. CCM seems to affect young patient with a

mean age of 22.4 years +/−18.2 (median: 19 years), al-

though both paediatric and elderly patients are involved

(1.2 - 72 years). It appears to be a female predominance

(F/M: 1.72). The most frequent location observed was

the cauda equine. Cervical spine was involved in 5 cases

only (16.7%).

The importance of recognising this particular variant

of meningioma relates specifically to its inordinately

aggressive clinical course despite its benign appearance.

Unlike the more typical meningioma, CCM’s propensity

for local recurrence has been well-established in the lit-

erature. The rate of recurrence found in this study was

40% (vs 4.8% for non CCMs) [25,26]. Although rare

event (7%), spinal metastasis in meningiomas is well

established [25,27-33]. It occurs either through ha-

ematogenous route or cerebro-spinal fluid. Metastases

occur in aproximately 0.2% of intracranial tumours [33].

Only 7% of them occur in vertebrae [33,34] and not all

meningiomas that metastasize are malignant. More than

60% of them originated from grade I meningiomas

[26,29]. Nevertheless, distant metastases are known to be

relatively more frequent arising from grade II or III sub-

types [35,36]. Malignant meningiomas seem to spread

H. NOURI ET AL.

300

through CSF more frequently [29,37-39]. However the

risk of CSF dissemination is not clear from literature. It

remains controversial whether surgical procedures may

play a role in the spread of the tumour via CSF [37,38].

Most of patients were operated on several times before a

metastasis occurred. Although, some cases seem to occur

in non-operated patients [26,40]. The lumbo-sacral re-

gion was a common site for spinal metastases [27]. The

first case of a metastatic meningioma to the sacrum was

reported by Lee [29] in 2002. However, whether distant

recurrences represent the capacity of CCM to metastasize

or a multifocal characteristic remains uncertain. Multi-

focal manifestation of CCM is well-described and the

distant recurrences may represent this [41]. To our know-

ledge, only one documented case of synchronous multi-

centric CCM was reported [9]. Our case seems to be

more likely a distant recurrence because of a drop me-

tastasis rather than a multifocal presentation but we

couldn’t conclude since the entire neuraxis was not im-

aged initially. This emphasizes the necessity to explore

the entire spine by MRI in cases of spinal meningioma.

The latency period between the diagnosis of primary

tumour and the appearance of metastasis reported in lit-

erature is variable, ranging from few months to more tan

20 years [41]. In our case, the latency of 17 years can be

explained by two facts: firstly, the very low mitotic ac-

tivity attests that it’s a slow growing lesion. Secondly,

the location to the sacrum and the anterior extension of

Table 1. Summary of intraspinal CCMs observed in present and previous reports. GTR: gross total resection; STR: subtotal

resection; RT: radiation therapy.

Author/year Age/sex Tumor location Treatment Outcome (recurrence metastasis)

Zorludemir (2) 1995

9/F 17/F

23/F 34/M

36/F 47/M

L3-L5 L4-L5

L5 L4-S1

L2-L5 L3-L4

GTR GTR

GTR GTR + RT

Recurrence at 6 months No No

Recurrence at 2 months No

Recurrence at 36 months, and brain metastasis

Prinz (4) 1996 38/M Sacrococcygeal GTR Multiple recurrences

Holtzman (5) 1996 32/M L3-L4 GTR No

Pimentel (6) 1998 55/M 21/F Cervical Lumbar GTR GTR No No

Cances (7) 1998 9/F L1-L4 GTR + RT Recurrence at 5 months

Dubois (8) 1998 10/F Cauda equine GRT+RT Recurrence at 6 months

Matsui (9)1998 9/F Multifocal T12, L2, L5GTR No

Jallo (10) 2001 1,8/F 8/F C3-C5 L3-L5 STR GTR Recurrence at 10 weeks and brain metastasis

Recurrence at 6 months

Yu (11) 2002 1.2/F T12-L1 GTR Recurrence at 4 months

Boet (12) 2004 34/M Lumbosacral STR + RT No

Liu (13) 2005 2.2/F T10-L1 GTR Recurrence at 60 months

Dhall (14) 2005 32/F Thoraco lumbar STR Recurrence

Jain (15) 2007 26/F Cauda equine GTR No

Colen (16) 2009 13/F L4-L5 GTR + RT No

Tong-tong (17) 2010 35/F C7 GTR No

Inoue (18) 2004 72/M C5-C6 GTR No

Heth (19) 2000 7/F L4-L5 GTR No

Oviedo (20) 2005 7/M L2-L3 GTR No

Epstein (21) 2005 41/F L3-L4 GTR No

Park (22) 2000 1.2/F Cauda equine GTR Recurrence at 18 months

Carra (23) 2001 1.9/M T11-L4 GTR No

Chen (24) 2004 41/F L4-L5 GTR No

Present report 9/M C4 GTR Sacral metastasis at 17 years

H. NOURI ET AL.

301

the tumour explain how such a huge mass could remain

asymptomatic for a long period.

Prognosis of spinal metastases is related to their clini-

cal progression. When it was rapid, death usually oc-

curred soon after the time of initial diagnosis. The prog-

nosis is especially bad in patients with neurologic deficit.

Treatment of spine metastatic meningiomas is pallia-

tive. Patients that had undergone surgical debulking

[27,28,31,35,36,42] showed no neurological improve-

ment. Palliative radiation therapy is the preferred modal-

ity of treatment. Although, irradiation has shown some

symptomatic relief, the paucity of cases doesn’t allow

clear conclusions concerning its real effect on survival

rate. Lee et al [38] used steroid for their 3 patients com-

bined to irradiation and reported some symptomatic im-

provement. Adjunction of steroid seems to be interesting

since neoplastic cells demonstrate positivity for proges-

terone receptors.

4. Conclusions

Clear cell meningioma constitutes a rare subset of ma-

lignant meningiomas. It has an aggressive clinical course

despite its histological appearance. A close follow-up

would be required due to the high risk of recurrence and

metastases. The early detection and irradiation of metas-

tatic lesions can improve their prognosis.

5. References

[1] D. Louis, Ohgaki, H. Wiestler, et al., “WHO Classifica-

tion—Tumours of the Nervous System,” 4th Edition, In-

ternational Agency for Research on Cancer, Lyon, 2007,

pp. 164-172.

[2] S. Zorludemir, B. W. Scheithauer, T. Hirose, et al., “Cler

Cell Meningioma: A Clinicopathologic Study of a Poten-

tially Aggressive Variant of Meningioma,” The American

Journal of Surgical Pathology, Vol. 19, No. 5, 1995, pp.

493-505. doi:10.1097/00000478-199505000-00001

[3] K. W. Ko, D. H. Nam, D. S. Kong, et al., “Relationship

between Malignant Subtypes of Meningioma and Clinical

Outcome,” Journal of Clinical Neuroscience, Vol. 14, No.

8, 2007, pp. 747-753. doi:10.1016/j.jocn.2006.05.005

[4] M. Prinz, S. Patt, T. Mitrovics, et al., “Clear Cell Men-

ingioma: Report of a Spinal Case,” General & Diagnostic

Pathology, Vol. 141, No. 3-4, 1996, pp. 261-267.

[5] R. N. N. Holtzman and S. C. Jorkman, “Nondural-Based

Lumbar Clear Cell Meningioma,” Journal of Neurosur-

gery, Vol. 84, No. 2, 1996, pp. 264-266.

doi:10.3171/jns.1996.84.2.0264

[6] J. Pimental, A. Fernandes, A. E. Pinto, et al., “Clear Cell

Meningioma Variant and Clinical Aggressiveness,” Clin-

ical Neuropathology, Vol. 17, No. 3, 1998, pp. 141-146.

[7] C. Cances, Y. Chaix, C. Karsenty, et al., “Clear Cell Me-

ningioma: Recurrent Intraspinal Tumor in a Child,” Ar-

chives de Pédiatrie, Vol. 5, No. 7, 1998, pp. 758-762.

doi:10.1016/S0929-693X(98)80062-6

[8] A. Dubois, A. Sevely, S. Boetto, et al., “Clear Cell Men-

ingioma of the Cauda Equine,” Neuroradiology, Vol. 40,

No. 11, 1998, pp. 743-747.

doi:10.1007/s002340050676

[9] H. Matsui, M. Kanamori, Y. Abe, et al., “Multifocal Clear

Cell Meningioma in the Spine: A Case Report,” Neurosur-

gical Review, Vol. 21, No. 2-3, 1998, pp. 171-173.

doi:10.1007/BF02389326

[10] G. I. Jallo, K. F. Kothbauer, V. M. Silvera, et al., “In-

traspinal Clear Cell Meningioma: Diagnosis and Man-

agement: Report of Two Cases,” Neurosurgery; Vol. 48,

No. 1, 2001, pp. 218-222.

[11] K. B. Yu, M. K. Lim, H. J. Kim, et al., “Clear Cell Men-

ingioma: CT and MR Imaging Findings in Two Cases

Involving the Spinal Canal and Cerebellopontine Angle,”

Korean Journal of Radiology, Vol. 3, No. 2, 2002, pp.

125-129. doi:10.3348/kjr.2002.3.2.125

[12] R. Boet, H. K. Ng, S. Kumta, et al., “Lumbosacral

Clear-Cell Meningioma Treated with Subtotal Resection

and Radiotherapy,” Journal of Clinical Neuroscience,

Vol. 11, No. 4, 2004, pp. 432-436.

doi:10.1016/j.jocn.2003.10.014

[13] P. I. Liu, G. C. Liu, K. B. Tsai, et al., “Intraspinal Clear

Cell Meningioma: Case Report and Review of Litera-

ture,” Surgical Neurology, Vol. 63, No. 3, 2005, pp.

285-289. doi:10.1016/j.surneu.2004.03.013

[14] S. S. Dhall, L. M. Tumialan, D. J. Brat, et al., “Spinal

Intradural Clear Cell Meningioma Following Resection

of a Suprasellar Clear Cell Meningioma. Case Report and

Recommendations for Management,” Journal of Neuro-

surgery, Vol. 103, No. 3, 2005, pp. 559-563.

doi:10.3171/jns.2005.103.3.0559

[15] D. Jain, M. C. Sharma, C. Sarkar, et al., “Clear Cell Me-

ningioma, an Uncommon Variant of Meningioma: A Cli-

nicopathologic Study of Nine Cases,” Journal of Neu-

ro-Oncology, Vol. 81, No. 3, 2007, pp. 315-321.

doi:10.1007/s11060-006-9237-7

[16] C. B. Colen, M, Rayes, J. McClendon Jr., et al., “Pediat-

ric Spinal Clear Cell Meningioma. Case Report,” Journal

of Neurosurgery Pediatrics, Vol. 3, No. 1, 2009, pp.

57-60.

[17] T.-T. Wu, L.-J. Bian, Z. Li, Y. Li, B.-N. Luo and Q.

Huang, “Clear Cell Meningioma with Anaplastic Features:

Case Report and Review of Literature,” Pathol-

ogy—Research and Practice, Vol. 206, No. 5, 2010, pp.

349-354. doi:10.1016/j.prp.2009.06.015

[18] T. Inoue, K. Miyamoto, H. Kodama, et al., “Cervical

Clear Cell Meningioma Mimicking a Vertebral Metasta-

sis,” Journal of Clinical Neuroscience, Vol. 12, No. 6,

2005, pp. 685-687. doi:10.1016/j.jocn.2004.08.019

[19] J. A. Heth, P. Kirby, A. H. Menezes, et al., “Intraspinal

Familial Clear Cell Meningioma in a Mother and Child,”

Journal of Neurosurgery, Vol. 93, No. 2, 2000, pp.

317-321.

[20] A. Oviedo, D. Pang, J. Zovikian, et al., “Clear Cell Men-

ingioma: Case Report and Review of the Literature,” Pe-

H. NOURI ET AL.

302

diatric and Developmental Pathology, Vol. 8, No. 3,

2005, pp. 386-390. doi:10.1007/s10024-005-0119-3

[21] N. Epstein, S. Drexler and J. Shneider, “Clear cell Men-

ingioma of the Cauda Equine in an Adult. Case Report and

Literature Review,” Journal of Spinal Disorders & Tech-

niques, Vol. 18, No. 6, 2005, pp. 539-543.

doi:10.1097/01.bsd.0000173314.98401.b5

[22] H. C. Park, M. J. Sohn, E. Y. Kim, et al., “Spinal Clear

Cell Meningiomas Presented with Progressive Parapresis

in Infancy,” Child’s Nervous System, Vol. 16, No. 9,

2000, pp. 607-610. doi:10.1007/PL00007302

[23] S. Carra, P. Drigo, M. Gadriman, et al., “Clear Cell Me-

ningioma in a 22 Months-Old Male; a Case Report and

Literature Review,” Pediatric Neurosurgery, Vol. 34, No.

5, 2001, pp. 264-267.

[24] M. H. Chen, S. J. Chen, S. M. Lin, et al., “A Lumbar

Cleare Cell Meningioma with Foraminal Extension in a

Renal Transplant Recipient,” Journal of Clinical Neuro-

science, Vol. 11, No. 6, 2004, pp. 665-667.

doi:10.1016/j.jocn.2003.10.024

[25] S. K. Ludwin and F. K. Conley, “Malignant Meningioma

Metastatizing through the Cerebrospinal Pathways,”

Journal of Neurology, Neurosurgery & Psychiatry, Vol.

38, No. 2, 1975, pp. 136-142. doi:10.1136/jnnp.38.2.136

[26] P. M. Son, M. Sacher, S. W. Strenger, et al., “Benign

Metastasizing Meningiomas,” American Journal of Neu-

roradiology, Vol. 8, No. 1, 1987, pp. 127-130.

[27] A. T. kimura, T. Orita, O. Hayashida, et al., “Malignant

Meningiomas Metastatizing through the Cerebrospinal

Pathway,” Acta Neurologica Scandinavica, Vol. 85, No.

5, 1992, pp. 368-371.

doi:10.1111/j.1600-0404.1992.tb04063.x

[28] K. Kamiya, T. Inagawa and R. Nagasako, “Malignant

Intraventricular Meningioma with Spinal Metastasis

through the Cerebrospinal Fluid,” Surgical Neurology,

Vol. 32, No. 3, 1989, pp. 213-218.

doi:10.1016/0090-3019(89)90181-X

[29] Y. Y. Lee, W. W. Hsu, T. J. Huang, et al., “Metastatic

Meningioma in the Sacrum: A Case Report,” Spine, Vol.

27, No. 4, 2002, pp. E100-E103.

doi:10.1097/00007632-200202150-00022

[30] W. C. Peh and Y. W. Fan, “Case Report: Intraventricular

Meningioma with Cerebelopontine Angle and Drop Me-

tastases,” The British Journal of Radiology, Vol. 68, No.

808, 1995, pp. 428-430.

doi:10.1259/0007-1285-68-808-428

[31] C. G. Riley, “Metastatizing Meningeal Tumour Case

Report,” The New Zealand Medical Journal, Vol. 73,

1974, pp. 210-214.

[32] F. J. Wippold II, J. G. Smimoitopoulos and T. K. Pilgram,

“Lesions of the Cauda Equine: A Clinical Pathology Re-

view from the Armed Forces Institute of Pathology,”

Clinical Neurology and Neurosurgery, Vol. 9, No. 4,

1997, pp. 229-234. doi:10.1016/S0303-8467(97)00095-4

[33] J. L Karasik and S. Mullens, “A Survey of Metastatic

Meningiomas,” Journal of Neurosurgery, Vol. 40, No. 2,

1974, pp. 206-212. doi:10.3171/jns.1974.40.2.0206

[34] R. Wasserkurg, E. Peyser and C. Lichtig, “Extracranial

Bone Metastases from Intracranial Meningiomas,” Surgical

Neurology, Vol. 12, No. 6, 1979, pp. 480-484.

[35] M. D. Conrad, C. Schonauer, I. Pelissou-Guyotat, et al.,

“Recurrent Lumbosacral Metastases from Intracranial

Meningioma. Report of a Case and Review of the Litera-

ture,” Acta Neurochirurgica, Vol. 143, No. 9, 2001, pp.

935-937. doi:10.1007/s007010170024

[36] S. A. Enam, S. Abdulrauf, B. Mehta, et al., “Metastasis in

Meningioma,” Acta Neurochirurgica, Vol. 138, No. 10,

1996, pp. 1172-1178. doi:10.1007/BF01809747

[37] M. C. Chamberlain and M. J. Glantz, “Cerebrospinal Fluid-

Dessiminated Meningioma,” Cancer, Vol. 103, No. 7,

2005, pp. 1427-1430. doi:10.1002/cncr.20926

[38] T. T. Lee and H. J. Landy, “Spinal Metastases of Malig-

nant Intracranial Meningioma,” Surgical Neurology, Vol.

50, No. 5, 1998, pp. 437-441.

doi:10.1016/S0090-3019(97)00348-0

[39] P. D. Delgado-Lopez, V. Martin-Velasco, J. M. Castilla-

Diez, et al., “Metastatic Meningioma to the Eleventh

Dorsal Vertebal Body: Total En Bloc Spondylectomy.

Case Report and Review of the Literature,” Neur- ocirur-

gia, Vol. 17, No. 3, 2006, pp. 240-249.

[40] S. W. Strenger, Y. P. Huang and V. P. Sachdez, “Malig-

nant Meningioma within the Third Ventricle: A Case

Report,” Neurosurgery, Vol. 20, No. 3, 1978, pp.

465-468. doi:10.1227/00006123-198703000-00019

[41] W. Lee, K. H. Chang, G. Choe, et al., “MR Imaging Fea-

tures of Clear Cell Meningioma with Diffuse Lep- to-

meningeal Seeding,” American Journal of Neuror-

adiology, Vol. 21, No. 1, 2000, pp. 130-132.

[42] S. Fuentes, P. Metellus, C. Bouvier, et al., “Metastatic

Meningioma to the First Thoracic Vertebral Body. A

Case Report and Review of the Literature,” Neurochirur-

gie, Vol. 48, No. 1, 2002, pp. 53-56.