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Case Report
Olfactory schwannoma: A report of two cases and literature review Zheng Wang1,3, Wei Zhang1,3, Gan You1,3, Jiangfei Wang1,3, Guilin Li2,3, Zhixian Gao1,3, Jian Xie1,3 Department of Neurosurgery, Beijing Tiantan Hospital, 2Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, 3Beijing Institute for Brain Disorders Brain Tumor Center, Beijing 100050, China 1
Abstract
Address for correspondence: Dr. Jian Xie, Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, No. 6 Tiantan Xili, Dongcheng District, Beijing 100 050, China. E‑mail: [email protected] Received : 14‑04‑2014 Review completed : 14-06‑2014 Accepted : 10‑08‑2014
Intracranial schwannoma is a kind of benign intracranial tumors, derived from neuron myelin sheath, growing slowly and curable. Olfactory schwannoma is an exceedingly rare kind of schwannoma, whose origin is still uncovered. Although several theories have been put up for pathogenesis of olfactory schwannoma, till now, none of these hypotheses has been widely accepted and acknowledged officially. Up to date, only 46 cases of olfactory schwannoma were reported across numerous institutes worldwide. Here we gathered two cases from Department of Neurosurgery in Beijing Tiantan Hospital across two years collection. Key words: Olfactory schwannoma, olfactory groove meningioma, subfrontal lesion
Introduction Olfactory schwannoma is an exceedingly rare disease, and until date, only 46 cases have been reported worldwide. We present two cases of olfactory schwannoma in whom the preoperative diagnosis was olfactory groove meningioma.
Case Reports Case 1 A 38‑year‑old woman presented with a history of intermittent vomiting of one‑month duration. Examination revealed no neurological deficits except diminished sense of smell. Cranial magnetic resonance imaging (MRI) revealed a 43 mm × 38 mm solid cystic lesion in left anterior cranial fossa with mixed T1‑ and T2‑weighted signals. The lesion enhanced significantly on contrast administration [Figure 1a-d]. Preoperative diagnosis was left olfactory groove meningioma. Access this article online Quick Response Code:
Website: www.neurologyindia.com PMID: *** DOI: 10.4103/0028-3886.141289
Neurology India | Jul-Aug 2014 | Vol 62 | Issue 4
Intraoperatively, the lesion was gray‑white in color and slightly tough with clear boundaries in the left olfactory groove invading the ethmoidal sinus. The lesion was completely excised [Figure 1e and f)] Postoperative period was uneventful with little improvement in sense of smell. Histopathological diagnosis was olfactory schwannoma. Microscopic images showed Antoni A type tumor cells, round or spindle‑shaped, and aligned regularly as a fibrous cord or vortex structure (single‑headed arrow); and Antoni B type cells were also seen (double‑headed arrow) [Figure 1g]. In another case, MRI scan showed an ovary lesion in the anterior cranial fossa [Figure 2a-d]. The preoperative impression was olfactory groove meningioma. Postoperatively, MRI scan showed that the tumor was totally removed [Figure 2e and f]. Histological examination confirmed the diagnosis of olfactory groove schwannoma [Figure 2g]. The common cranial nerves for schwannomas are eight, facial nerves, and trigeminal. Schwannoma of the olfactory bulb is uncommon as the olfactory nerve is unsheathed by schwann cells. Until date, there have been no convincing theories that are widely accepted to explain the origin of olfactory groove schwannoma.[1‑4] Thus far, only 46 cases of olfactory schwannomas have been reported[5] In most reported cases of olfactory groove schwannoma, the chief complaints were 423
[Downloaded free from http://www.neurologyindia.com on Thursday, September 25, 2014, IP: 202.177.173.189] || Click here to download free Android application fo this journal Wang, et al.: Two cases of olfactory schwannoma
a
b
c
e
f
g
d
Figure 1: Preoperative and postoperative magnetic resonance imaging (MRI) and histopathological examination in Case 1 (a) and (b) MRI scan showed a round anterior cranial fossa lesion. Ethmoidal sinus was invaded, and the middle line was pushed to the opposite side. (c) and (d) showed that the lesion was solid cystic and was significantly contrasted after the patient was injected contrast medium. (e) and (f) showed that the lesion was completely removed. (g) showed typical schwannoma pathological characteristics (H and E, ×200)
a
b
c
e
f
g
d
Figure 2: Preoperative and postoperative magnetic resonance imaging (MRI) and histopathological examination in Case 2 (a) and (b) MRI scan showed an anterior cranial fossa lesion. Ethmoidal sinus was invaded. (c) and (d) showed that the lesion was significantly contrasted after injecting contrast medium. (e) and (f) showed that the lesion was completely removed. (g) showed typical schwannoma pathological characteristics (H and E, ×200)
headache, vomiting, seizure, hyposmia, diplopia, or even anosmia.[6‑8] Physical examination often revealed 424
loss or reduced sense of smell, which is often neglected by the patient. Surgery is the preferred treatment for Neurology India | Jul-Aug 2014 | Vol 62 | Issue 4
[Downloaded free from http://www.neurologyindia.com on Thursday, September 25, 2014, IP: 202.177.173.189] || Click here to download free Android application fo this journal Wang, et al.: Two cases of olfactory schwannoma
olfactory schwannoma. Cerebrospinal fluid rhinohroea and associated central nervous system infections are the most common complications of the surgery. Often the differential diagnosis is olfactory groove schwannoma and is often the preoperative diagnosis in most of the reported cases.[5,9] Histological examination confirms the diagnosis.
References 1.
Esiri M. Russell and Rubinstein’s pathology of tumors of the nervous system. Sixth edition. J Neurol Neurosurg Psychiatry 2000;68:538D. 2. Redekop G, Elisevich K, Gilbert J. Fourth ventricular schwannoma. Case report. J Neurosurg 1990;73:777‑81. 3. Huang PP, Zagzag D, Benjamin V. Intracranial schwannoma presenting as a subfrontal tumor: Case report. Neurosurgery 1997;40:194‑7. 4. Figueiredo EG, Soga Y, Amorim RL, Oliveira AM, Teixeira MJ. The
Neurology India | Jul-Aug 2014 | Vol 62 | Issue 4
puzzling olfactory groove schwannoma: A systematic review. Skull Base 2011;21:31‑6. 5. Sauvaget F, Francois P, Ben Ismail M, Thomas C, Velut S. Anterior fossa schwannoma mimicking an olfactory groove meningioma: Case report and literature review. Neurochirurgie 2013;59:75‑80. 6. Adachi K, Yoshida K, Miwa T, Ikeda E, Kawase T. Olfactory schwannoma. Acta Neurochir (Wein) 2007;149:605‑10. 7. Darie I, Riffaud L, Saikali S, Brassier G, Hamlat A. Olfactory ensheathing cell tumour: Case report and literature review. J Neurooncol 2010;100:285‑9. 8. Saberi H, Khashayar P. Olfactory groove schwannoma masquerading as an orbital mass. Neurosciences (Riyadh) 2008;13:73‑6. 9. Tan TC, Ho LC, Chiu HM, Leung SC. Subfrontal schwannoma masquerading as meningioma. Singapore Med J 2001;42:275‑7. How to cite this article: Wang Z, Zhang W, You G, Wang J, Li G, Gao Z, et al. Olfactory schwannoma: A report of two cases and literature review. Neurol India 2014;62:423-5. Source of Support: Nill, Conflict of Interest: None declared.
425
Copyright of Neurology India is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Case Report
Olfactory schwannoma: A report of two cases and literature review Zheng Wang1,3, Wei Zhang1,3, Gan You1,3, Jiangfei Wang1,3, Guilin Li2,3, Zhixian Gao1,3, Jian Xie1,3 Department of Neurosurgery, Beijing Tiantan Hospital, 2Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, 3Beijing Institute for Brain Disorders Brain Tumor Center, Beijing 100050, China 1
Abstract
Address for correspondence: Dr. Jian Xie, Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, No. 6 Tiantan Xili, Dongcheng District, Beijing 100 050, China. E‑mail: [email protected] Received : 14‑04‑2014 Review completed : 14-06‑2014 Accepted : 10‑08‑2014
Intracranial schwannoma is a kind of benign intracranial tumors, derived from neuron myelin sheath, growing slowly and curable. Olfactory schwannoma is an exceedingly rare kind of schwannoma, whose origin is still uncovered. Although several theories have been put up for pathogenesis of olfactory schwannoma, till now, none of these hypotheses has been widely accepted and acknowledged officially. Up to date, only 46 cases of olfactory schwannoma were reported across numerous institutes worldwide. Here we gathered two cases from Department of Neurosurgery in Beijing Tiantan Hospital across two years collection. Key words: Olfactory schwannoma, olfactory groove meningioma, subfrontal lesion
Introduction Olfactory schwannoma is an exceedingly rare disease, and until date, only 46 cases have been reported worldwide. We present two cases of olfactory schwannoma in whom the preoperative diagnosis was olfactory groove meningioma.
Case Reports Case 1 A 38‑year‑old woman presented with a history of intermittent vomiting of one‑month duration. Examination revealed no neurological deficits except diminished sense of smell. Cranial magnetic resonance imaging (MRI) revealed a 43 mm × 38 mm solid cystic lesion in left anterior cranial fossa with mixed T1‑ and T2‑weighted signals. The lesion enhanced significantly on contrast administration [Figure 1a-d]. Preoperative diagnosis was left olfactory groove meningioma. Access this article online Quick Response Code:
Website: www.neurologyindia.com PMID: *** DOI: 10.4103/0028-3886.141289
Neurology India | Jul-Aug 2014 | Vol 62 | Issue 4
Intraoperatively, the lesion was gray‑white in color and slightly tough with clear boundaries in the left olfactory groove invading the ethmoidal sinus. The lesion was completely excised [Figure 1e and f)] Postoperative period was uneventful with little improvement in sense of smell. Histopathological diagnosis was olfactory schwannoma. Microscopic images showed Antoni A type tumor cells, round or spindle‑shaped, and aligned regularly as a fibrous cord or vortex structure (single‑headed arrow); and Antoni B type cells were also seen (double‑headed arrow) [Figure 1g]. In another case, MRI scan showed an ovary lesion in the anterior cranial fossa [Figure 2a-d]. The preoperative impression was olfactory groove meningioma. Postoperatively, MRI scan showed that the tumor was totally removed [Figure 2e and f]. Histological examination confirmed the diagnosis of olfactory groove schwannoma [Figure 2g]. The common cranial nerves for schwannomas are eight, facial nerves, and trigeminal. Schwannoma of the olfactory bulb is uncommon as the olfactory nerve is unsheathed by schwann cells. Until date, there have been no convincing theories that are widely accepted to explain the origin of olfactory groove schwannoma.[1‑4] Thus far, only 46 cases of olfactory schwannomas have been reported[5] In most reported cases of olfactory groove schwannoma, the chief complaints were 423
[Downloaded free from http://www.neurologyindia.com on Thursday, September 25, 2014, IP: 202.177.173.189] || Click here to download free Android application fo this journal Wang, et al.: Two cases of olfactory schwannoma
a
b
c
e
f
g
d
Figure 1: Preoperative and postoperative magnetic resonance imaging (MRI) and histopathological examination in Case 1 (a) and (b) MRI scan showed a round anterior cranial fossa lesion. Ethmoidal sinus was invaded, and the middle line was pushed to the opposite side. (c) and (d) showed that the lesion was solid cystic and was significantly contrasted after the patient was injected contrast medium. (e) and (f) showed that the lesion was completely removed. (g) showed typical schwannoma pathological characteristics (H and E, ×200)
a
b
c
e
f
g
d
Figure 2: Preoperative and postoperative magnetic resonance imaging (MRI) and histopathological examination in Case 2 (a) and (b) MRI scan showed an anterior cranial fossa lesion. Ethmoidal sinus was invaded. (c) and (d) showed that the lesion was significantly contrasted after injecting contrast medium. (e) and (f) showed that the lesion was completely removed. (g) showed typical schwannoma pathological characteristics (H and E, ×200)
headache, vomiting, seizure, hyposmia, diplopia, or even anosmia.[6‑8] Physical examination often revealed 424
loss or reduced sense of smell, which is often neglected by the patient. Surgery is the preferred treatment for Neurology India | Jul-Aug 2014 | Vol 62 | Issue 4
[Downloaded free from http://www.neurologyindia.com on Thursday, September 25, 2014, IP: 202.177.173.189] || Click here to download free Android application fo this journal Wang, et al.: Two cases of olfactory schwannoma
olfactory schwannoma. Cerebrospinal fluid rhinohroea and associated central nervous system infections are the most common complications of the surgery. Often the differential diagnosis is olfactory groove schwannoma and is often the preoperative diagnosis in most of the reported cases.[5,9] Histological examination confirms the diagnosis.
References 1.
Esiri M. Russell and Rubinstein’s pathology of tumors of the nervous system. Sixth edition. J Neurol Neurosurg Psychiatry 2000;68:538D. 2. Redekop G, Elisevich K, Gilbert J. Fourth ventricular schwannoma. Case report. J Neurosurg 1990;73:777‑81. 3. Huang PP, Zagzag D, Benjamin V. Intracranial schwannoma presenting as a subfrontal tumor: Case report. Neurosurgery 1997;40:194‑7. 4. Figueiredo EG, Soga Y, Amorim RL, Oliveira AM, Teixeira MJ. The
Neurology India | Jul-Aug 2014 | Vol 62 | Issue 4
puzzling olfactory groove schwannoma: A systematic review. Skull Base 2011;21:31‑6. 5. Sauvaget F, Francois P, Ben Ismail M, Thomas C, Velut S. Anterior fossa schwannoma mimicking an olfactory groove meningioma: Case report and literature review. Neurochirurgie 2013;59:75‑80. 6. Adachi K, Yoshida K, Miwa T, Ikeda E, Kawase T. Olfactory schwannoma. Acta Neurochir (Wein) 2007;149:605‑10. 7. Darie I, Riffaud L, Saikali S, Brassier G, Hamlat A. Olfactory ensheathing cell tumour: Case report and literature review. J Neurooncol 2010;100:285‑9. 8. Saberi H, Khashayar P. Olfactory groove schwannoma masquerading as an orbital mass. Neurosciences (Riyadh) 2008;13:73‑6. 9. Tan TC, Ho LC, Chiu HM, Leung SC. Subfrontal schwannoma masquerading as meningioma. Singapore Med J 2001;42:275‑7. How to cite this article: Wang Z, Zhang W, You G, Wang J, Li G, Gao Z, et al. Olfactory schwannoma: A report of two cases and literature review. Neurol India 2014;62:423-5. Source of Support: Nill, Conflict of Interest: None declared.
425
Copyright of Neurology India is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
