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Table of Contents    
Year : 2022  |  Volume : 70  |  Issue : 2  |  Page : 784-787

Nasoethmoidal Schwannoma as a Mimicar of Esthesioneuroblastoma: A Case Report and Literature Review

1 Department of Neurosurgery, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
2 Department of General Surgery, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
3 Department of Anaesthesia, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
4 Department of Otorhinolaryngology, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India

Date of Submission14-Jul-2020
Date of Decision30-Oct-2020
Date of Acceptance15-Dec-2020
Date of Web Publication3-May-2022

Correspondence Address:
Dr. Varun Aggarwal
Department of Neurosurgery, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab - 151 203
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0028-3886.344679

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 » Abstract 

Nasoethmoidal schwannomas are rare lesions and their presentation with intracranial extension is even rarer. Here, a patient presenting with rhinorrhea, epistaxis, and proptosis of left eye was diagnosed with giant nasoethmoidal schwannoma extending to frontal lobe and orbit, which was managed with bifrontal craniotomy with endoscopic transnasal gross total excision. This being predominantly a benign lesion has good prognosis if total excision is achieved.

Keywords: Bifrontal craniotomy, endoscopic transnasal, intracranial extension, nasoethmoidal schwannoma
Key Message: Nasoethmoidal schwannoma with intracranial extension is a rare type of sinonasal schwannoma. These tumors are frequently misdiagnosed on MRI as esthesioneuroblastoma. Management of nasoethmoidal schwannoma should involve bifrontal craniotomy with or without transnasal approach with gross total excision.

How to cite this article:
Narang A, Aggarwal V, Jain R, Maheshwari C, Ramesh A, Singh G. Nasoethmoidal Schwannoma as a Mimicar of Esthesioneuroblastoma: A Case Report and Literature Review. Neurol India 2022;70:784-7

How to cite this URL:
Narang A, Aggarwal V, Jain R, Maheshwari C, Ramesh A, Singh G. Nasoethmoidal Schwannoma as a Mimicar of Esthesioneuroblastoma: A Case Report and Literature Review. Neurol India [serial online] 2022 [cited 2022 Jun 27];70:784-7. Available from: https://www.neurologyindia.com/text.asp?2022/70/2/784/344679

Nasoethmoidal schwannomas are rare lesions of nasal cavity. Schwannomas develop from schwann cells of nerves hence can develop anywhere in the body.[1] Forty five percent of schwannomas occur in the head and neck region, but only fewer than 50 have been reported in the nasoethmoid region of nasal cavity.[2] They are benign, slow growing lesions that cause pressure thinning and erosion of the bony margins and spread locally.[3] They present with only few early symptoms or no symptoms and a long progressive history due to benign nature.

 » Case Presentation Top

A 33-year-old female presented with chief complaint of the left eye proptosis since 3 months along with irritation in the left eye, three episodes of epistaxis and rhinorrhea. Patient had no anosmia. On examination no neurological deficit was present. Endoscopic examination of left nasal cavity showed nasal mass lateral to middle turbinate. Contrast-enhanced MRI showed a lesion in left frontal lobe causing mass effect on the left lateral ventricle and subfalcine herniation, with extension in left ethmoid sinus with compression on the left eye ball. On T1WI, lesion was hypointense; on T2WI, it was heterogeneous, and on contrast T1WI, lesion was heterogeneously enhanced [Figure 1]a, [Figure 1]b, [Figure 1]c, [Figure 1]d, [Figure 1]e, [Figure 1]f, [Figure 1]g, [Figure 1]h. These MRI finding were suggestive of olfactory esthesioneuroblastoma. The patient underwent bifrontal craniotomy with ligation of superior sagittal sinus near the cribriform plate. Tumor was grayish, solid, nonsuckable, moderately vascular, having poor arachnoid plane with brain tissue, and attachment with falx. Lesion was eroding into the anterior cranial fossa (ACF) and lamina papyracea compressing the periorbita of left orbit. It was extending into both the ethmoid sinus reaching lateral to middle turbinate of the left nose. Major part of the tumor was excised with transcranial approach, but tumor in the nasal cavity was inaccessible transcranially; hence, nasal part of the tumor was excised after middle turbinectomy with endoscopic transnasal approach. Gross total resection was achieved. Intradural ACF repair with carpeting of ACF with pericranial flap was done transcranially. Transnasally, the defect was packed with abdominal fat covered with mucosa and reinforced with adhesive glue. Postoperative period was uneventful. Postoperative CECT scan showed gross total resection and no hematoma [Figure 2]a, [Figure 2]b, [Figure 2]c, [Figure 2]d. The patient was discharged on the third postoperative day. Histopathology revealed schwannoma and palisaded verocay bodies [Figure 3]. After 7-month follow up, the patient was asymptomatic with no recurrence.
Figure 1: Preoperative images. (1a) T1 MRI-weighted axial image reveal hypointense to isointense lesion with compression on falx. (1b) T2 MRI-weighted sagittal image showing lesions appearance as heterogeneous. (1c–1e) Contrast T1 axial, coronal, and sagittal, respectively, lesion shows intense contrast enhancement with nonenhancing areas. 1f: SWI MRI showed blooming in the lesion suggestive of haemorrhage. (1g-1h) CT PNS coronal and CT PNS coronal bone window shows well-defined isodense mass lesion in left ethmoid sinus extending to nasal cavity causing erosion and destruction of medial orbital wall and cribriform plate

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Figure 2: Postoperative images. 2a-d: Contrast-enhanced CT axial and coronal study demonstrates gross total resection of tumor with resection cavity and no enhancing residual lesion

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Figure 3: Histopathological images. Micrograph shows hypercellular areas and hypocellular areas under 10× power with hypercellular areas being verocay bodies (Antony A)

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 » Discussion Top

Nasoethmoid schwannomas are rare benign tumors. They arise from nerve sheaths of the local nerves of the nasal cavity of either sensory branches of trigeminal nerves or local autonomic nerves, and since there are many nerve branches so the exact origin cannot be determined.[1] They grow in bony confines of the nasal cavities.[2] Intracranial extension of these tumors are very rare. These are a type of sinonasal schwannomas that are classified into one of these four types based on their location: subfrontal (olfactory groove), nasoethmoidal (sinonasal), frontoethmoidal (primarily intracranial with extension into the paranasal sinuses), or ethmofrontal (primarily sinonasal with intracranial extension).[4] To the best of our knowledge, only 11 cases of nasoethmoidal schwannoma with intracranial extension have been reported in the literature [Table 1]. Of the reported cases, 58% were males and 42% females. The symptoms arose gradually due to mass effect of the tumor. Presenting symptoms in the reported cases were anosmia, visual disturbances, epistaxis, headache, and some were asymptomatic.[12] Fifty percent of patients reported with headache and/or anosmia as the chief complaint, followed by visual disturbances in 33% and epistaxis in 25% [Table 2]. The differential diagnosis for a nasoethmoidal schwannoma most commonly includes esthesioneuroblastoma, squamous cell carcinoma, adenocarcinoma, lymphoma, meningioma, and fungal infection [Table 3]. Radiological features of these tumor are nonspecific on CT and MRI, but some features may help in making differential diagnosis [Table 4].[11],[13] Histologically, schwannomas present in a biphasic histological pattern: Antoni A and Antoni B areas. Antoni A areas are characterized by spindle-shaped Schwann cells, which occasionally show areas of nuclear palisading surrounding an eosinophilic acellular region, referred to as ''Verocay bodies.'' In contrast, Antoni B areas are typified by loose myxoid stroma with round nuclei distributed in a haphazard manner. Immunohistochemical positivity for S-100 protein is present. According to the literature, these tumors can be resected gross totally by bifrontal craniotomy.[2] Among the 11 cases previously mentioned in literature, only one case was managed with subtotal resection and concurrent radiotherapy was given as it was malignant schwannoma on histopathology.[11] We managed this case by bifrontal craniotomy for intracranial part of tumor combined with endoscopic transnasal resection of the intranasal part of tumor. Postoperatively, our patient did not have CSF leak though 33% of cases reported CSF rhinorrhea in the published cases. We recommend bifrontal craniotomy combined with endoscopic transnasal approach to aid in gross total excision of the tumor mass with meticulous repair of the dural defect. Since the lesion is mostly benign, complete cure can be achieved with gross total excision which should be our goal.
Table 1: Review of literature on nasoethmoid schwannomas with intracranial extension

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Table 2: Summary of nasoethmoidal schwannoma with intracranial extension (Published cases included present case)

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Table 3: Differential diagnosis of sinonasal lesion

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Table 4: Radiological features of common sinonasal lesion with intracranial extension

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 » Conclusion Top

Nasoethmoidal schwannoma is a benign tumor that very rarely presents with intracranial extension. There are 11 cases previously described in literature, and this report describes the 12th case. Radiological findings being nonspecific, histopathological examination provides the basis of diagnosis. Bifrontal craniotomy with endoscopic transnasal excision is a preferred approach for surgical management.

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Conflicts of interest

There are no conflicts of interest.

 » References Top

Siqueira MG, Jennings E, Moraes OJ, Santos MT, Zanon N, Mattos BJ, et al. Naso-ethmoid schwannoma with intracranial extension: Case report. Arq Neuropsiquiatr 2001;59:421-3.  Back to cited text no. 1
Eichberg DG, Menaker SA, Buttrick SS, Gultekin SH, Komotar RJ. Nasoethmoid schwannoma with intracranial extension: A case report and comprehensive review of the literature. Cureus 2018;10:e3182.  Back to cited text no. 2
George KJ, Price R. Nasoethmoid schwannoma with intracranial extension. Case report and review of literature. Br J Neurosurg 2009;23:83-5.  Back to cited text no. 3
Yoneoka Y, Akiyama K, Seki Y, Hasegawa G, Kakita A. Frontoethmoidal schwannoma with exertional cerebrospinal fluid rhinorrhea: Case report and review of the literature. World Neurosurg 2018;111:381-5.  Back to cited text no. 4
Zovickian J, Barba D, Alksne JF. Intranasal schwannoma with extension into the intracranial compartment: Case report. Neurosurgery 1986;19:813-5.  Back to cited text no. 5
Enion DS, Jenkins A, Miles JB, Diengdoh JV. Intracranial extension of a naso-ethmoid schwannoma. J Laryngol Otol 1991;105:578-81.  Back to cited text no. 6
Bavetta S, McFall MR, Afshar F, Hutchinson I. Schwannoma of the anterior cranial fossa and paranasal sinuses. Br J Neurosurg 1993;7:697-700.  Back to cited text no. 7
Fujiyoshi F, Kajiya Y, Nakajo M. CT and MR imaging of nasoethmoid schwannoma with intracranial extension. AJR Am J Roentgenol 1997;169:1754-5.  Back to cited text no. 8
Gatscher S, Love S, Coakham HB. Giant nasal schwannoma with intracranial extension. Case illustration. J Neurosurg 1998;89:161.  Back to cited text no. 9
Sharma R, Tyagi I, Banerjee D, Pandey R. Nasoethmoid schwannoma with intracranial extension. Case report and review of literature. Neurosurg Rev 1998;21:58-61.  Back to cited text no. 10
Ogunleye AO, Ijaduola GT, Malomo AO, Oluwatosin O M, Shokunbi W A, Akinyemi OA, et al. Malignant schwannoma of the nasal cavity and paranasal sinuses in a Nigerian. Afr J Med Med Sci 2006;35:489-93.  Back to cited text no. 11
Hong CS, Pomeraniec IJ, Starke RM, Shaffrey ME. Nasoethmoid schwannoma with intracranial extension. Case report and review of the literature. Br J Neurosurg 2018;32:565-6.  Back to cited text no. 12
Som PM, Lidov M, Brandwein M, Catalano P, Biller HF. Sinonasal esthesioneuroblastoma with intracranial extension: Marginal tumor cysts as a diagnostic MR finding. AJNR Am J Neuroradiol 1994;15:1259-6.  Back to cited text no. 13


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1], [Table 2], [Table 3], [Table 4]


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