Indian Journal of Dental Research

SHORT COMMUNICATION
Year
: 2010  |  Volume : 21  |  Issue : 3  |  Page : 457--459

Schwannoma of the tongue: An unusual presentation in a child


Giridhar S Naidu1, Samindra Mohan Sinha2,  
1 Department of Oral Medicine & Radiology, College of Dental Surgery, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
2 Department of Pedodontics & Preventive Dentistry, College of Dental Surgery, B.P. Koirala Institute of Health Sciences, Dharan, Nepal

Correspondence Address:
Giridhar S Naidu
Department of Oral Medicine & Radiology, College of Dental Surgery, B.P. Koirala Institute of Health Sciences, Dharan
Nepal

Abstract

Schwannomas are benign tumors of nerve sheath and quite uncommon in the oral cavity. In contrast to the earlier reports in the literature, a confounding case of a lingual schwannoma presenting as a symptomatic and exophytic growth on the ventral surface of the tongue in a 12-year-old boy is discussed here.



How to cite this article:
Naidu GS, Sinha SM. Schwannoma of the tongue: An unusual presentation in a child.Indian J Dent Res 2010;21:457-459


How to cite this URL:
Naidu GS, Sinha SM. Schwannoma of the tongue: An unusual presentation in a child. Indian J Dent Res [serial online] 2010 [cited 2021 May 6 ];21:457-459
Available from: https://www.ijdr.in/text.asp?2010/21/3/457/70790


Full Text

Schwannomas (neurilemmomas or neurinomas) are benign encapsulated nerve sheath neoplasms composed of Schwann cells first described by Verocay in 1908. [1] Schwannomas in the head and neck regions constitute 25% of all extracranial schwannomas, but only 1% show intraoral origin. [1],[2] Of these, one such case of a lingual schwannoma confounded us due to its unusual presentation as a symptomatic and exophytic growth on the ventral surface of the tongue in a 12-year-old boy in contrast to the earlier reports in the literature.

 Case Report



A 12-year-old Nepalese boy, reported to our clinic with a growth in the ventral aspect of the tongue purportedly of 15 days duration. The growth was asymptomatic at first and nonprogressive but ulcerated after few days and began to bleed readily. Paresthesia and dysgeusia to sour and sweet foods was reported in the right half of the tongue. No history of trauma was elicited nor any systemic or local infections. The medical and family histories were unremarkable. A physical examination revealed a moderately built and nourished male with no known systemic disorders. Intraoral examination showed an exophytic growth in the ventral surface of the right half of the tongue measuring 20×10 mm in size [Figure 1]. The base of the growth was an area of ulceration, which had firm, well-defined borders that were non-tender on palpation. The growth itself appeared necrotic and covered by slough. It was soft, friable, and non-tender on palpation and bled readily on manipulation. The dentition and the adjacent oral mucosa revealed no abnormalities. Tongue movements were unrestricted and simple gustatory testing to sweet, sour, and salt yielded normal results.{Figure 1}

A provisional diagnosis of a pyogenic granuloma was made and inflammatory fibrous hyperplasia, fibroepithelial polyp, granulomatous ulcer, schwannoma, neurofibroma, and granular cell tumor were considered as an alternative diagnoses. After obtaining a complete blood profile, which was within normal limits, incisional biopsy was planned under local anesthesia. On attempting to obtain the specimen the soft and friable nature of the growth prompted an excision of the entire lesion along with the ulcerated base. Because encapsulation was not evident, blunt dissection was carried out till the muscle plane to free the tongue of any lesional tissue [Figure 2]. Direct invasion into the adjacent muscle or nerve fibers was not evident nor was any significant bleeding encountered.{Figure 2}

The histopathology with routine hematoxylin and eosin-stained sections revealed predominantly spindle-like cells with abundant fibrillar cytoplasm along with a mixed inflammatory cell infiltrate. Areas of palisading arrangement of nuclei suggestive of Verocay bodies were noted [Figure 3]. Necrotic material with bacterial colonies was also noted. However, the bacterial and fungal cultures failed to show any pathogens. Immunohistochemistry with S-100 neural marker showed strong reactivity [Figure 4], but remained negative to muscle marker actin. A conclusive diagnosis of schwannoma was made based on the above findings. The patient was reviewed after a week and adequate healing was appreciated. A 3-month follow-up [Figure 5] showed no signs of recurrence and the patient remained asymptomatic.{Figure 3}{Figure 4}{Figure 5}

 Discussion



Peripheral nerve tumors of the oral cavity include schwanomma, neurofibroma, traumatic neuroma, and 2 very rare entities, the palisaded encapsulated neuroma and neurothekeoma. Embryologically, Schwann cells arise during the fourth week of development from ectomesenchymal cells of the neural crest. They enhance nerve conductance by either forming a thin barrier around peripheral nerve fibers or a thick myelin sheath. [1],[2]

Schwannomas in the head and neck regions constitute 25% of all extracranial schwannomas, but only 1% show intraoral origin. [1,2] Of these, 50% tumors have been shown to have a direct relation with a nerve. [2] Within the tongue, schwannomas may rise from the hypoglossal nerve, glossopharyngeal nerve, [3] or the lingual nerve. Although they may arise at any age, the peak incidence varies between the third and the sixth decades with only 4 cases of lingual schwannoma reported in children. [4] Clinically, schwannomas are solitary, slow growing, smooth surfaced, and usually asymptomatic. Ulceration of the overlying mucosa is uncommon and generally the result of trauma. [2] Lesions of the tongue that are exophytic or fungating are extremely rare, with only 2 such reports till date; one in an adult and the other in a 9-year-old child. [5] Interestingly, our patient hailed from the remote hilly regions of Nepal and may have reported to our clinic only when the growth was sufficiently symptomatic after bleeding and paresthesia were encountered. Hence, the short duration of clinical presentation as revealed by the patient would seem improbable. However, the unusual and misleading presentation of a symptomatic, exophytic, and poorly encapsulated schwannoma was unique to this case.

Diagnostic investigations include ultrasound scanning, computed tomography, magnetic resonance imaging (MRI), and fine-needle aspiration cytology. However, MRI is the best choice in detailing of the extent of the tumors and correlates well with operative findings. [4] The definitive diagnosis is based on histopathology with the presence of alternating patterns of Antoni A and B areas, nuclear palisading, whorling of cells, and Verocay bodies. The absence of large multipolar fibroblasts, reticulin, and a mucoid matrix distinguishes schwannoma from other histologic entities, such as meningioma, leiyomyoma/leiyomyosarcoma, palisaded myofibroblastoma, and pleomorphic hyalinizing angiectatic tumor of soft tissue, with similar findings. [1],[2] The use of a myriad of immunohistochemistry markers beyond neural-specific S-100 stain for identification is therefore not uncommon in such lesions.

Schwannomas are managed by complete surgical excision, but wide excision is not recommended because schwannomas show few recurrences after surgery. [2] Malignant transformation of schwannoma is an exceptionally rare event and can be safely disregarded. [1] The above case was of peculiar interest due to the symptomatic, poorly encapsulated, and exophytic clinical presentation in a young boy.

References

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3Biswas D, Marnane CN, Mal R, Baldwin D. Extracranial head and neck schwannomas: A 10-year review. Auris Nasus Larynx 2007;34:353-9.
4Karaca CT, Habesoglu TE, Naiboglu B, Habesoglu M, Oysu C, Egeli E, et al. Schwannoma of the tongue in a child. Am J Otolaryngol 2010;31: 46-8.
5Bassichis BA, Mcclay JE. Pedunculated neurilemmoma of the tongue base. Otolaryngol Head Neck Surg 2004;130:639-41.