C A S E R E P O R T ors_1115 82..85

Lingual schwannoma – a case reportR.K. Verma1, S. Dhingra1, K. Gupta2 & N.K. Panda1

1Department of Otolaryngology, Head and Neck surgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India2Department of Histopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, India

Abstract

Schwannoma are nerve sheath tumours, and 20–40% of all schwannomasare seen in the head and neck region. However, intra-oral schwannomas arevery rare, and account 1% of all schwannomas in the head and neck region.Lingual schwannomas close to the tip of tongue is even rarer, common sitesbeing the base of the tongue, lips, cheek and lateral border of tongue. Wereport schwannoma of the tongue close to the tip and also describe theclassical clinical and radiological findings.

Key words:rare, schwannoma, tip of tongue

Correspondence to:Dr RK Verma

Department of Otolaryngology

Head and Neck Surgery

Post Graduate Institute of Medical Education and

Research

Chandigarh 160012

India

Tel.: +91-9914209761

Fax: +91-172-2744401

email: roshanverma@hotmail.com

Accepted: 19 January 2011

doi:10.1111/j.1752-248X.2011.01115.x

Introduction

The schwannomas or neurilemmomas are nervesheath tumours originating from peripheral nerves.Neurofibromas are benign neoplasms composed ofneurites, schwann cells and fibroblasts within a collag-enous or myxoid matrix, while schwannomas arebenign, slow-growing, encapsulated neoplasms arisingfrom Schwann cells of nerve sheath that forms themyelin sheaths of the myelinated peripheral nerves1.

Only about 25% of all schwannomas are located inthe head and neck, of which only 1% shows an intra-oral origin2.

We present the case of a 26-year-old male patientwith schwannoma of lateral border of tongue, anddiscuss its histological findings and differential diagno-sis of such lesions.

Case report

A 26-year-old male presented to our out patientdepartment (OPD) with a slow-growing, painlessswelling on the anterior aspect of left side of the tonguefor last 1 month. It was associated with difficulty while

speaking and swallowing. He also complained of occa-sional mild bleeding while brushing teeth. There wasno history of trauma to the site. The patient was anon-smoker.

Examination of the oral cavity showed a 2 ¥ 2 cmpolypoidal mass on the left lateral border of the tongue,0.5 cm behind the tip of the tongue. The polypoidalmass had a narrow stalk, was firm in consistency andnon-tender. There was no fasciculation or atrophy ofthe tongue. No regional cervical adenopathy wasdetected. (Fig. 1)

Magnetic resonance imaging (MRI) of the tongueshowed hyperintense lesion on the left lateral border ofthe tongue on T2 and isointense to muscle on T1weighted sequence. (Fig. 2)

An excision of the mass was done under generalanaesthesia along with cautery of the base of tumour.Post-operative recovery was uneventful.

Microscopically, the lesion was composed of hyper-plastic stratified squamous epithelium which wasfocally ulcerated with underlying dense mixed inflam-matory infiltrate comprising of eosinophils, neutro-phils and lymphocytes (Fig. 3A,B). The subepitheliumwas expanded by an unencapsulated infiltrative

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© 2011 John Wiley & Sons A/S

tumour composed of oval to spindle cells, arranged inan organoid pattern forming Verocay bodies (Fig. 3C).The neoplastic cells revealed nuclear and cytoplasmicimmunopositivity with S-100 (Fig. 3D), and werenegative with smooth muscle actin (SMA), therebyconfirming a diagnosis of a schwannoma. S-100protein family are useful as markers for certain tumorsand epidermal differentiation. It can be found in mela-nomas, 50% of malignant peripheral nerve sheathtumors, schwannomas, paraganglioma stromal cells,histiocytoma and clear cell sarcomas.

Discussion

Schwannoma was first reported by Virchow in1908 and are benign tumours of peripheral nervesoriginating in the nerve sheaths3. Neurilemmoma,neurolemoma, neurinoma, perineural fibroblastoma,peripheral glioma and peripheral nerve sheath tumourare the synonyms of this tumour. The incidence of headand neck schwannoma ranges from 25 to 40%, andcommon sites of involvement are nose, nasopharynx,orbit, larynx, parapharyngeal region of neck4,5.However, schwannomas account for just 1% of benigntumours reported in the oral cavity. Tongue, palate,cheek, gingiva and buccal mucosa are common sites inthe oral cavity6.

Schwannomas can arise in any age but the peakincidence is in the second and third decade. Schwan-nomas do not show any gender predilection. Lingualschwannomas usually present as slow-growing, sessileor pedunculated, encapsulated tumours on the dorsalor ventral surface of tongue7,8. Neurological weaknessof the tongue may or may not be present9. Our patientwas a 26-year-old male and had pedunculated schw-annoma on the lateral border of the tongue withoutany hypoglossal palsy.

The low-incidence intra-oral schwannomas oftenleads to omission of this tumour on the differentialdiagnosis of oropharyngeal tumours. The differentialdiagnosis lingual schwannoma includes neuro-fibromas, leiomyomas, rhabdomyomas, granular celltumours, retention cysts, hemangiomas, lymphangio-

Figure 1 Schwannoma presenting as fleshy

polypoidal mass close to tip of the tongue (A) and

the excised lesion (B).

Figure 2 Magnetic resonance imaging showing hyperintense lesion on

T2 weighted image.

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83Oral Surgery 4 (2011) 82–85.

© 2011 John Wiley & Sons A/S

mas, pyogenic granulomas and benign salivary glandtumours10. When the lesion presents as a pedunculatedmass, the possibility of papilloma, aberrant thyroidtissue and hypertrophied lingual tonsil tissue must alsobe included10.

MRI shows that schwannoma appears as a smoothwell-demarcated tumour, which appears isointense tomuscle on T1-weighted sequence and homegenouslyhyperintense on T2-wieghted sequence11.

In more than 50% of intra-oral lesions, it is not pos-sible to differentiate between tumours of the lingual,hypoglossal and glossopharyngeal nerve as identifica-tion of the nerve is difficult. Direct relation with a nervecan be demonstrated in only approximately 10–50% ofthe cases. MRI may sometimes help to delineate thenerve of origin of a schwannoma12.

The diagnosis is confirmed by histopathologicalevaluation and consists of two main patterns. The firstconsists of Schwann cells arranged in a close twistingfashion termed Antoni type A. The nuclei often lie inparallel rows or in a palisading arrangement. Whentwo rows of palisading nuclei have enclosed betweenthem a space filled with amorphous collagen, thisarrangement is called a Verocay body13. The secondtype of tissue is called Antoni type B and is composed ofvery loosely arranged elongated Schwann cells set in amyxoid morphology and meshwork of reticulum fibresand microcysts10,14. Immunostaining for S-100 wasdone to establish the neural origin of the tumour, andSMA was carried out to rule out a leiomyoma whichoften occurs in the tongue and histologically shows

spindle-shaped cells with eosinophilic cytoplasm. Thecells expressed S-100 and were negative for SMA.Thus, confirming the diagnosis of schwannoma.

These tumours must be differentiated from neurofi-bromas which are more frequently associated withneurological weakness and have a stronger tendencyfor malignant transformation. Neurofibromas arecomposed of not only schwann cells but other elementslike large multipolar fibroblasts, reticulin and a mucoidmatrix. Histologically, neurofibromas are less cellularand more disorganized, lack the organization of theAntoni A palisades found in their schwannoma coun-terparts15. This disorganized composition has beendescribed as having a ‘shredded carrot’ appearance16.

Complete surgical excision of the tumour, whilepreserving the nerve of origin is the treatment of choicefor these tumours. Excision by using Co2 laser hasbecome popular in recent times. These tumours areusually unresponsive to radiotherapy17. Recurrencesare rare after complete excision of tumour.

In conclusion, lingual schwannomas, although rare,should be included in the differential diagnosis ofpedunculated tongue masses. However, definitivediagnosis requires a histopathological evaluation. Acomplete surgical excision is curative in such cases.

References

1. Enzinger FM, Weiss SW. Soft Tissue Tumors, 3rdedition. St Louis, MO: Mosby-YearBook Inc,1995:821–88.

Figure 3 (A) Lesion confined to the subepithe-

lium with overlying hyperplastic stratified squa-

mous epithelium (hematoxylin and eosin (H&E)

X25). (B) Schwannoma composed of oval to

spindle shaped cells with surrounding inflamma-

tory infiltrate (H&E X100). (C) Spindle cells regi-

mented together forming Verocay bodies

(arrow) (H&E X200). (D) Neoplastic cells positive

with S-100 (Immunoperoxidase X200,

anti-S-100).

Schwannoma of tip of tongue Verma et al.

84 Oral Surgery 4 (2011) 82–85.

© 2011 John Wiley & Sons A/S

2. Arda HN, Akdogan O, Arda N et al. An unusual site foran intraoral schwannoma: a case report. Am JOtolaryngol 2003;24:348–50.

3. Mosharrafa TM, Kuppersmith RB, Porter JP, DonovanDT. Pathologic quiz case 1. Malignant peripheral nervesheath tumor of the ethmoidal sinus. Arch OtolaryngolHead Neck Surg 1997;123:654, 656–7.

4. Bansal R, Trivedi P, Patel S. Schwannoma of the tongue.Oral Oncol Extra 2005;41:15–17.

5. Pfeifle R, Baur DA, Paulino A, Helman J. Schwannomaof the tongue: report of 2 cases. Oral Maxillofac Surg2001;59:802–4.

6. Leu YS, Chang KC. Extracranial head and neckschwannomas: a review of 8 years experience. ActaOtolaryngol 2002;122:435–7.

7. Mevio E, Gorini E, Lenzi A, Migliorini L. Schwannomaof the tongue: one casereport. Rev Laryngol Otol Rhinol2002;123:259–61.

8. Yamazaki H, Kaneko A, Ota Y, Tsukinoki K.Schwannoma of the mental nerve:usefulness ofpreoperative imaging: a case report. Oral SurgOral Med Oral Pathol Oral Radiol Endod2004;97:122–6.

9. Gomez Beldarrain M, Fernandez Canton G,Garcia-Monco JC. Hypoglossal schwannoma: anuncommon cause of twelfth-nerve palsy. Neurologia2000;15:182–3.

10. Spandow O, Fagerlund M, Bergmark L, Boquist L.Clinical and histopathological features of a large

parapharyngeal neurilemoma located at the base oftongue. ORL 1999;61:25–30.

11. Okura A, Shigemori M, Abe T, Yamashita M, Kojima K,Noguchi S. Hemiatrophy of the tongue due tohypoglossal schwannoma shown by MRI. Head NeckRadiol 1994;36:239–40.

12. Okura A, Shigemori M, Abe T, Yamashita M, Kojima K,Noguchi S. Hemiatrophy of the tongue duetohypoglossal schwannoma shown by MRI.Neuroradiology 1994;36:239–40.

13. Oda Y, Kawahara E, Minamoto T, Ueda Y, Ikeda K,Nagai Y et al. Immunohistochemical studies on thetissue localization of collagen types I, III, IV, V and VIin schwannomas. Correlation with ultrastructuralfeatures of the extracellular matrix. Virchows Arch BCell Pathol Incl Mol Pathol 1988;56:153–63.

14. Cohen M, Wang MB. Schwannoma of the tongue: twocase reports and review of the literature. Eur ArchOtorhinolaryngol 2009;266:1823–9.

15. Bassichis BA, McClay JE. Pedunculated neurilemomaof the tongue base. Otolaryngol Head Neck Surg2004;130:639–41.

16. Frosch M, Anthony D, De Girolami U. Central nervoussystem. In: Kumar V, editor: Robbins and Cotran:Pathologic Basis of Disease, 7th edition. Philadelphia,PA: Elsevier, 2004:1411–13. [Copyright].

17. Sutay S, Tekinsoy B, Ceryan K, Aksu Y. Submaxillaryhypoglossal neuri-lemmoma. J Laryngol Otol1993;107:953–4.

Verma et al. Schwannoma of tip of tongue

85Oral Surgery 4 (2011) 82–85.

© 2011 John Wiley & Sons A/S