CARTILAGINOUS CHORISTOMA OF THE TONGUE: A CASE REPORT WITH IMMUNOHISTOCHEMISTRY IN A SECONDARY HEALTH CARE FACILITY

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B.O Castano¹, R.T Oluwakuyide², O.S. Keshinro³, O.A Akinshipo⁴, Y.A Salami⁵

1. Consultant Family Dentist, Dental Clinic, General Hospital Ifako-Ijaiye, Lagos..
2. Department of Oral and Maxillofacial Pathology, Dental Centre General Hospital Lagos Island.
3. Force Pathologist, Nigeria Police Force, Police Hospital Falomo, Ikoyi, Lagos.
4. Department of Oral and Maxillofacial Pathology, College of Medicine, University of Lagos.
5. Department of Oral and Maxillofacial Surgery, Dental Centre, Randle General Hospital, Surulere, Lagos.

Abstract

Background: Soft tissue cartilaginous choristoma (STC) is a mass of mature hyaline cells occurring in abnormal location. It is also referred to as extraskeletal choristoma; a rare lesion that frequently occurs on the tongue in orofacial region.
The objective is to bring to the attention of Clinicians especially in secondary health care facilities the need of thorough investigations of tissue specimen to prevent misdiagnosis and avail themselves every diagnostic tool in the management of all oral swellings.

Case presentation: A 7-year old boy presented in Dental clinic in a secondary health care facility with history of an asymptomatic, non-tender and slow growing swelling on the dorsum of the tongue of 3 years duration. Surgical excision was done under general anaesthesia. Histopathological and immunohistochemical evaluations were the tools used to establish its diagnosis.

Conclusion: Soft tissue choristoma is rare benign swelling that mostly occur in the anterior two-third of the tongue and can be misdiagnosed clinically but diagnostic tools like histopathology and immunohistochemistry will help confirm it.

Keywords: Choristoma, Tongue, Secondary health facility, Immunohistochemistry

Introduction

Soft tissue choristomas are rare mesenchymal benign neoplasms, also referred to as extraskeletal choristoma.¹ This lesion was first described by Berry in 1892, typically occurs on the lateral border of the anterior two-third of the tongue, while the ventral surface and the posterior one-third are rarely involved.² Cartilaginous choristoma describes an island of tumour like mass of histologically normal hyaline tissue occurring in an abnormal location (“heterotopism”); which has been attributed to embryonic developmental abnormalities of the neural tube.^3,4 Importantly, choristoma should be categorized from entities like hamartomas and teratomas; while hamartomas are non-neoplastic developmental malformations which may be unifocal or multifocal, comprising a mixture of cytologically normal mature cells and tissues in a disorganized architectural pattern which are indigenous to the anatomic location; with one of its constituents predominating.³ Teratomas on the other hand, are true neoplasms composed of a variety of parenchymal cell types of more than one germ layer.³ Soft tissue cartilaginous choristoma also known as soft tissue chondroma,^4,5 constitutes about 1.5% of benign soft tissue tumours.^1,4 Orofacial choristomas are very rare but occur mostly in the tongue, masseter, preauricular region, gingiva, tonsil, and nasal cavity.^4,5 They are mostly seen between 3rd and 4th decade of life and usually asymptomatic, slow growing well defined nodules extending into the surrounding tissues.^4,6 We present our experience of soft tissue choristoma of the tongue in a Lagos secondary health facility.

CASE PRESENTATION
A 7-year old boy-child presented in the Dental Clinic, Somolu General Hospital with a painless, slow-growing and asymptomatic mass of 3 years duration. There was no history of trauma, only discomfort during swallowing. Clinical examination revealed an elevated oval swelling on the dorsum of the left half of the tongue which was about 2x2cm in its widest diameter, extending mediolaterally at around the posterior limit of the anterior two-thirds (Figure 1) . The overlying mucosa was normal. No tenderness was elicited and the lesion was firm in consistency.