Journal of Postgraduate Medicine
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CASE REPORTS
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Year : 1994  |  Volume : 40  |  Issue : 4  |  Page : 218-9  

Intraparenchymal schwannoma of the frontal lobe.

M Deogaonkar, A Goel, RD Nagpal, AP Desai 
 Dept of Neurosurgelry, KEM Hospital, Parel, Bombay, Maharashtra.

Correspondence Address:
M Deogaonkar
Dept of Neurosurgelry, KEM Hospital, Parel, Bombay, Maharashtra.

Abstract

A 45 year old woman with bifrontal headaches and progressive diminution in vision over 6 months was found to have bilateral papilloedema. CT scan showed large right frontal lesion with surrounding oedema. Right basal frontotemporal craniotomy was performed to excise the multinodular, intraparenchymatous tumor. Hispathology confirmed the diagnosis of schwannoma. Post-operative course was uneventful with disappearance of pre-operative signs and symptoms.



How to cite this article:
Deogaonkar M, Goel A, Nagpal R D, Desai A P. Intraparenchymal schwannoma of the frontal lobe. J Postgrad Med 1994;40:218-9


How to cite this URL:
Deogaonkar M, Goel A, Nagpal R D, Desai A P. Intraparenchymal schwannoma of the frontal lobe. J Postgrad Med [serial online] 1994 [cited 2020 Jul 13 ];40:218-9
Available from: http://www.jpgmonline.com/text.asp?1994/40/4/218/522


Full Text




  ::   IntroductionTop


Intraparenchymatous schwannomas of the central, nervous system are rare. A literature survey revealed reports of 29 such cases[1]. Amongst these 18 were supratentorial and 11 were infratentorial in location. Three of the 18 supratentorial tumours were in the frontal lobe[2],[3],[4]. In this report the clinical presentation, radiological imaging, operative findings and histopathology of a large right frontal schwannoma are described.


  ::   Case reportTop


A 45-year-old woman had bifrontal headaches and progressive diminution of vision for 6 months. Bilateral gross papilloedema was the only abnormal finding. Computerised tomographic (CT) scan showed a large right frontal, intensely enhancing lesion with extensive surrounding oedema [Figure:1].

With a presumptive radiological diagnosis of a meningioma, the lesion was exposed through a right basal frontotemporal craniotomy. As expected the brain was oedematous. There were dilated emmissary veins and marked thinning of the squamous temporal bone suggesting a long-standing increase in the intracranial pressure. The lesion was firm, entirely intraparenchymatous and only moderately vascular. The multinodular tumour was excised enmasse. On histopathological examination, the tissue was seen to be composed of mixed Antoni A and B variety of schwannoma [Figure:2]. Postoperative course was uneventful. The headaches rapidly subsided and the papilloedema cleared.


  ::   DiscussionTop


Schwannomas are benign nerve sheath tumours and account for about 8% of intracranial tumours[5]. Intraparenchymatous schwannomas, unrelated to cranial nerves are rare. Schwann cells are not indigenous to brain substance and hence histogenesis of these tumours has attracted a lot of speculation. Redekop, et al supported the theory of distorted embryogenesis. Riggs and Clary[7] postulated that the origin of these tumours is from the proliferation of Schwann cells found in the perivascular plexuses[7]. Russell and Rubenstien suggested conversion of pial cells to Schwann cells, and called this process as 'schwannosis.' Prakash et al[8] suggested misplaced myelinated nerve fibres and accompanying Schwann cells occurred in the brain as hamartomas and acted as a nidus for these tumours. Ramamurthi[9] suggested displaced neural crest cells in developing nervous system to be the origin of these tumours. A difference from multipotent mesenchymal cells has also been suggested[10]. Some cases associated with neurofibromatosis have been reported[5].

Symptoms depend on the location of these tumours. Though Russell and Rubenstein[5] stressed an early age of onset and male preponderance, this has been the exception rather than the rule. Duration of the symptoms is usually long and there are only minimal deficits at the time of presentation, despite the large tumour size. This suggests slowly growing tumours. The extensive edema around the tumour has not been a constant observation in the reported cases. Neuroradiological tests are non-specific. Even with CT and magnetic resonance imaging a preoperative diagnosis is impossible. Histopathologically these tumours need to be differentiated from microcystic meningiomas (with prominent nuclear palisading) and pilocytic astrocytomas which previously were called as ‘central schwannomas’[11]. Electron microscopy and immunohistochemistry helps in the differentiation[5]. Long-term outcome after excision is generally good[12].


  ::   AcknowledgmentTop


The authors acknowledge with gratitude support and encouragement of Dr. Sunil K Pandya and Dr. Anil P Karapurkar. Dr. Naina Goel edited the manuscript.

References

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12Ross DA, Edwards MSB, Wilson CB. Intramedullary neurilemomas of the spinal cord: report of two cases and review of literature. Neurosurgery 1986; 19:458464.

 
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