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Year : 2020  |  Volume : 68  |  Issue : 6  |  Page : 1497--1499

Intracerebral Schwannoma with Perivascular Meningioangiomatosis-like Extension in Surrounding Glia

Kiran P Malhotra1, Hardeep S Malhotra2, Rakesh K Singh3, Shivi Mohini4, Nuzhat Husain1,  
1 Department of Pathology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Gomti Nagar, Lucknow, Uttar Pradesh, India
2 Department of Neurology, King George Medical University, Lucknow, Uttar Pradesh, India
3 Department of Neurosurgery, Dr. Ram Manohar Lohia Institute of Medical Sciences, Gomti Nagar, Lucknow, Uttar Pradesh, India
4 Department of Radiodiagnosis, Sri Ram Murti Smarak Functional Imaging and Medical Centre, Lucknow, Uttar Pradesh, India

Correspondence Address:
Dr. Kiran P Malhotra
Department of Pathology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Gomti Nagar, Lucknow-226010
India




How to cite this article:
Malhotra KP, Malhotra HS, Singh RK, Mohini S, Husain N. Intracerebral Schwannoma with Perivascular Meningioangiomatosis-like Extension in Surrounding Glia.Neurol India 2020;68:1497-1499


How to cite this URL:
Malhotra KP, Malhotra HS, Singh RK, Mohini S, Husain N. Intracerebral Schwannoma with Perivascular Meningioangiomatosis-like Extension in Surrounding Glia. Neurol India [serial online] 2020 [cited 2021 Mar 6 ];68:1497-1499
Available from: https://www.neurologyindia.com/text.asp?2020/68/6/1497/304096


Full Text



Sir,

An 18-year-old male patient presented with recurrent headaches for one year. He had two previous episodes of complex partial seizures over one year. No previous head trauma or suggestive family history was present. Magnetic Resonance Imaging (MRI) of the brain showed a right frontal intraparenchymal lesion measuring 4.2 Õ 2.2 Õ 1.9 cm, solid-cystic in nature, with perilesional edema and without any midline shift. Intense enhancement of dura was seen on T1-GAD (gadolinium) enhanced images along with contrast enhancement of adjoining dura. Susceptibility weighted angiography (SWAN) images did not show any vascular changes or calcification. A choline peak was seen on MR Spectroscopy [Figure 1]. Right frontal craniotomy with excision of lesion was performed. Peroperatively, the lesion was intra-axial, cystic-solid, yellow-greyish, firm, and vascular.{Figure 1}

On histopathology, an unencapsulated cellular tumour was seen within glia with predominantly hypercellular and few hypocellular areas. The cellular areas showed monomorphic spindle cells in fascicles and palisades. No necrosis or atypical mitoses were seen. The periphery of the lesion was ill-defined with numerous tumor islands within surrounding glia. Similar cell nests were also noted around surrounding blood vessels resembling meningioangiomatosis [Figure 2]. The morphologic diagnosis of schwannoma was confirmed by nuclear positivity for S-100 protein on immunohistochemistry. The lesion was negative for Epithelial Membrane Antigen (EMA) and Glial Fibrillary Acidic Protein (GFAP). Ki 67 proliferation index was <1% in both the tumor and surrounding islands. CD34 staining was negative in the lesion but highlighted presence of blood vessels within the islands of tumor surrounding the main lesion [Figure 3]. A diagnosis of intracerebral schwannoma with infiltration along perivascular spaces resembling meningioangiomatosis was made. The patient is being managed conservatively with anti-epileptic drugs and is doing well six months post-surgery.{Figure 2}{Figure 3}

Intracranial schwannomas are rare and usually arise from peripheral nerves which innervate the cranial dura or along the intracranial portions of trigeminal and vestibular nerves or rarely within ventricles.[1] Intracerebral schwannomas comprise less than 1% of intracranial schwannomas; 84 such cases are on record.[2],[3],[4] MRI examination in these cases has shown intraparenchymal lesions with surrounding edema, similar to ours.[2] In addition, our case showed presence of contrast enhancement of adjacent dura, prompting the possible differentials of cystic glioma, meningioangiomatosis, lymphomatosis cerebri, dural lymphoma, metastases, Rosai-Dorfman disease and Solitary fibrous tumour. However, a diagnosis of intracerebral schwannoma could be made with conviction on histomorphology.

The finding of perivascular islands with schwannoma like morphology in the surrounding glia was an unusual feature in our case. Few cases of malignant intracerebral schwannomas are on record, however this was excluded due to lack of cytologic atypia and low Ki67 proliferation index in our case.[2],[5],[6] Intracerebral schwannomas in the setting of NF 2 have been reported rarely; but were excluded due to absence of suggestive family history, skin lesions, or vestibular schwannomas on MRI.[6] Similarly, a link with schwannomatosis was excluded, since no family history or associated meningiomas were seen.[7] Perivascular schwannosis is known to show presence of microscopic nodules of perivascular Schwann cell proliferation. However this lesion is almost always found within the spinal cord in association with neoplasms, syringomyelia, or traumatic scarring.[8]

In view of the atypical dural enhancement and perivascular Schwann cell proliferation, a similarity to meningioangiomatosis was considered. However; the SWAN images did not show any vascular changes within the lesion. The lesion was also EMA negative and S-100 positive, unlike meningioangiomatosis. Three cases of intracerebral schwannomas with meningioangiomatosis-like spread are on record.[9],[10],[11] Similar to our case, the previous cases occurred in children; (2 in the frontal and one in occipital lobe), had no history suggestive of NF2 or evidence of recurrence.[8],[10]

Our case suggests the probability of a shared pathogenesis between intracerebral schwannomas and meningioangiomatosis. An insight into the same may be gained by the similar tract followed by perivascular nerves and perforating arteries when they exit from Virchow Robin spaces. It has been suggested earlier, that the Schwann cells surrounding this perivascular nerve plexus may be the progenitors of intracerebral schwannomas.[1] It remains to be seen whether they represent a limited intracerebral manifestation of NF2 since both have a high propensity to occur in these patients. Follow-up is essential to determine the long-term course of this distinctive lesion.

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Conflicts of interest

There are no conflicts of interest.

References

1Wong ST, Moes G, Ernest K, Zovickian J, Kim JY, Pang D. Innervation of the brain, intracerebral Schwann cells and intracerebral and intraventricular schwannomas. Childs Nerv Syst 2014;30:815-24.
2Erongun U, Ozkal E, Acar O, Uygun A, Kocaoğullar Y, Gungor S. Intracerebral schwannoma: Case report and review. Neurosurg Rev 1996;19:269-74.
3Andrade GC, Paiva Neto MA, Braga FM. Thalamic intracerebral schwannoma: Case report. Arq Neuropsiquiatr 2002;60:308-13.
4Bhatoe HS, Srinivasan K, Dubey AK. Intracerebral schwannoma. Neurol India 2003;51:125-7.
5Maiuri F, Colella G, D'Acunzi G, De Caro Mdel B. Malignant intracerebellar schwannoma. J Neurooncol 2004;66:191-5.
6Doi E, Ozaki F, Yabumoto M, Moriwaki H, Hayashi S, Komai N. Multiple malignant intracerebral schwannomas in von Recklinghausen's disease--report of a case. No Shinkei Geka 1983;11:93-8.
7Louis DN, Ohgaki H, Wiestler OD, Cavenee WK, editors. WHO Classification of Tumors of the Central Nervous System Revised. 4th ed. Lyon: International Agency for Research on Cancer (IARC); 2016.
8McLendon RE, Rosenblum MK, Bigner DD, editors. Russel & Rubinstein's Pathology of Tumors of the Nervous System. 7th ed. London: Hodder Arnold; 2006.
9Ishihara M, Miyagawa-Hayashino A, Nakashima Y, Haga H, Takahashi JA, Manabe T. Intracerebral schwannoma in a child with infiltration along perivascular spaces resembling meningioangiomatosis. Pathol Int 2009;59:583-7.
10Auer RN, Budny J, Drake CG, Ball MJ. Frontal lobe perivascular schwannoma. Case report. J Neurosurg 1982;56:154-7.
11Bristol RE, Coons SW, Rekate HL, Spetzler RF. Invasive intracerebral schwannoma mimicking meningioma in a child. Childs Nerv Syst 2006;22:1483-6.