IJNS 2016; 05(03): 172-175
DOI: 10.1055/s-0036-1585458
Short Illustrated Review
Thieme Medical and Scientific Publishers Private Ltd.

Deep Sylvian Meningioma: A Case Report and Review of the Literature

Nidhal Matar
1  Department of Neurological Surgery, Institut National de Neurologie, Tunis, Tunisia
,
Kais Maamri
1  Department of Neurological Surgery, Institut National de Neurologie, Tunis, Tunisia
,
Adnene Boubaker
1  Department of Neurological Surgery, Institut National de Neurologie, Tunis, Tunisia
,
Jalel Kallel
1  Department of Neurological Surgery, Institut National de Neurologie, Tunis, Tunisia
,
Hafedh Jemel
1  Department of Neurological Surgery, Institut National de Neurologie, Tunis, Tunisia
› Author Affiliations
Further Information

Address for correspondence

Nidhal Matar, MD
Institut National de Neurologie
Tunis
Tunisia   

Publication History

11 February 2016

18 May 2016

Publication Date:
05 December 2016 (online)

 

Abstract

Introduction Meningiomas are extra-axial tumors. They usually display a dural attachment, although meningiomas without dural attachment are extremely rare and reported only occasionally in the literature. In this article, the authors present a new case of a deep sylvian meningioma and briefly review the relevant literature.

Case Report We present the case of a 39-year-old man presented with 1- month history of headache associated with an episode of generalized tonic–clonic seizure. Neurological examination showed no abnormality. Magnetic resonance imaging (MRI) demonstrated a lesion located in the right temporo-frontal region which was isointense on T1 and hypointense on T2 with homogeneous enhancement after gadolinium administration. Coronal, axial, and sagittal MRI revealed no dural attachment and the mass appeared to be completely surrounded by brain parenchyma. Intraoperatively, the lesion was presented as a subcortical mass and was mainly in the posterior part of right sylvian fissure. The histological diagnosis showed a World Health Organization grade I meningioma, transitional type.

Conclusion Deep sylvian meningiomas are a rare entity. Preoperative diagnosis is difficult. Nevertheless, neurosurgeons and neuropathologists should be aware of this possibility and should include this hypothesis in the differential diagnosis of an intraparenchymal tumor.


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Introduction

Meningiomas are extra-axial tumors deriving from the arachnoid cap or meningothelial cells. They usually display a dural attachment. Whereas, meningiomas without dural attachment, are extremely rare and reported only occasionally in the literature. In this paper, the authors present a new case of deep sylvian meningioma and briefly review the relevant literature.


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Case Report

A 39-year-old man presented at hospital with a 1-month history of headache associated with only one episode of generalized tonic–clonic seizure. Neurological examination showed no abnormality. Computing tomography (CT) of the brain revealed an isodense mass lesion in the right temporo-frontal region with homogeneous enhancement. Magnetic resonance imaging (MRI) demonstrated a 50 × 40 mm mass lesion which was isointense on T1- ([Fig. 1]) and hypointense on T2-weighted images ([Fig. 2]), with an homogeneous enhancement after gadolinium administration. A small cystic lesion was adjacent to the interior pole of the tumor. Coronal, axial, and sagittal MRI ([Fig. 3]) revealed no dural attachment. The mass appeared to be mainly located near the deep right sylvian fissure. The tumor caused peritumoral white matter edema. The first diagnosis was brain metastasis.

Zoom Image
Fig. 1 Axial T1-weighted image reveals a well-defined mass that is isointense with the brain.
Zoom Image
Fig. 2 Axial T2-weighted axial image reveals an iso-hypointense mass with marked peritumoral edema.
Zoom Image
Fig. 3 T1-weighted images with gadolinium demonstrating the homogenously enhanced tumor without dural attachment: Axial (A), Coronal (B), and sagittal (C).

The patient underwent a right fronto-pterional craniotomy. The dura and cortical surface appeared intact. Through a cortical incision, a brown tumor was reached ∼1.5 cm below the surface. It was a solid mass and well demarcated from normal parenchyma. However, inferior pole of the tumor was firmly adherent to the superior division of the middle cerebral artery and contained numerous perforators. The cyst contained xanthochromic fluid. The tumor was dissected carefully and removed totally. The postoperative course was uneventful and the patient was discharged without any neurodeficit.

The histological examination revealed a tumor tissue composed of meningeal cells arranged in whorls and interesting beams, mitoses were rare and there was no necrosis. Immunohistochemical findings showed that the tumor cells were positive for vimentin and focally positive for epithelial membrane antigen. On the basis of these findings, it was concluded that the tumor was a World Health Organization (WHO) grade I meningioma of transitional type. Ten months after surgery, upon check-up, brain MRI showed no recurrence of the tumor.


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Discussion

Meningiomas arise from meningothelial cells that line the arachnoid membrane, hence most of them are dural-based lesions and commonly located along the falx, tentorium, sphenoid bone, or over the convexity. Meningiomas without direct contact to the dura mater have been scarcely described. Cushing and Eisenhardt[1] first recognized and described these tumors using the term ‘‘meningiomas without dural attachment,” and classified them into five varieties: intraventricular, pineal region, deep sylvian, intraparenchymal or subcortical, and others.

Deep sylvian meningiomas are a very rare entity.[2] To our knowledge, including the present case, only 27 cases are reported in the international literature ([Table 1]). According to some authors, these meningiomas probably arise from arachnoid cap cells that are found in the Virchow–Robin spaces along the cerebral vasculature.[3]

Table 1

Reported cases of deep sylvian meningiomas

Authors (year)

Age

Sex

Clinical presentation

Tissue type

Cushing et al (1938)[1]

8 y

48 y

M

F

Seizures

Seizures

Psammomatous

Psammomatous

Barcia-Goyanes et al (1953)[4]

20 y

F

Seizures

Psammomatous

Mori et al (1977)[5]

23 y

M

Seizures

Transitional

Saito et al (1979)[6]

31 y

F

Seizures

Psammomatous

Tsuchida et al (1981)[7]

46 y

M

Headache

Meningotheliomatous

Okamoto et al (1985)[8]

27 y

35 y

F

F

Headache

Seizures

Fibroblastic

Fibroblastic

Hirao et al (1986)[9]

34 y

F

Seizures

Fibroblastic

Silbergeld et al (1988)[10]

4 y

F

Seizures

Meningotheliomatous

Drake et al (1986)[11]

3 y

M

Headache

Malignant

Cho et al (1990)[12]

2 y

M

Seizures,

hemiparesis

Transitional

Graziani et al (1992)[13]

19 y

M

Headache,

hemiparesis

Psammomatous

Mori et al (1994)[14]

12 y

M

Headache

Transitional

Chiocca et al (1994)[15]

26 y

F

Seizures

Fibroblastic

Matsumoto et al (1997)[16]

62 y

F

Seizures

Psammomatous

Cooper et al (1997)[17]

62 y

F

Seizures

Transitional

Mitsuyama et al (2000)[18]

20 mo

Seizures

Fibroblastic

Kaplan et al (2002)[19]

11 y

M

Seizures

Atypical

Chang et al (2005)[20]

35 y

M

Seizures

Transitional

Mclver et al 2005[21]

23 y

M

Seizures

Chordoid

Eghwrudjakpor et al (2006)[22]

73 y

F

NS

NS

Samson et al (2009)[2]

6 y

M

Seizures

WHO G I

Cecchi et al (2009)[3]

23 y

M

Headache,

hemiparesis

Atypical

Miyahara et al (2011)[23]

34 y

F

Seizures

Transitional

Fukushima et al (2014)[24]

10 y

M

Seizures

Sclerosing

Our case

39 y

M

Seizures

Transitional

Abbreviations: F, female; G, grade; M, male; NS, not stated; WHO, World Health Organization.


By reviewing the literature, these meningiomas occur mainly in young adults with a middle age around 26.5 years (8 cases were aged less than 14 years). There is a significant male predominance especially in the pediatric cases (pediatric sex ratio, 7/1). This epidemiological description seems in sharp contrast with the well-known middle-aged female prevalence of the ‘‘classic” meningioma. Clinically, the majority of patients presented with seizure (20 cases). Three patients complained from motor weakness, and six others from headache.

On MR imaging, there were the same characteristics as for “classic meningioma”: isointense T1, hyperintense T2, and homogenous enhancement with gadolinium, but without any dural attachment and totally surrounded by brain parenchyma. When reported, peritumoral edema is described as severe or moderate in most patients. Calcifications are rarely described and there is only one patient with an intratumoral hemorrhage.

On histopathological examination, twenty-one were WHO grade I, two WHO grade II, and two WHO grade III. Psammomatous and transitional types are the most common (16 cases). Prognostic factors are the same as for the other types of meningioma. They basically depend on the histological grade, quality of resection, and the importance of vessels sacrifice.


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Conclusion

Deep sylvian meningiomas are a rare entity. Preoperative diagnosis is difficult considering the rarity and the similarity of imaging findings to other more common intra-axial lesions. Nevertheless, neurosurgeons and neuropathologists should be aware of this possibility and should include this hypothesis in the differential diagnosis of an intraparenchymal tumor.


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Address for correspondence

Nidhal Matar, MD
Institut National de Neurologie
Tunis
Tunisia   


  
Zoom Image
Fig. 1 Axial T1-weighted image reveals a well-defined mass that is isointense with the brain.
Zoom Image
Fig. 2 Axial T2-weighted axial image reveals an iso-hypointense mass with marked peritumoral edema.
Zoom Image
Fig. 3 T1-weighted images with gadolinium demonstrating the homogenously enhanced tumor without dural attachment: Axial (A), Coronal (B), and sagittal (C).