Bilateral cervical accessory tragus: a rare pediatric neck mass

INTRODUCTION

An accessory tragus (AT) is a small elevation of skin that contains a bar of elastic cartilage and is usually found along an imaginary line drawn from the tragus to the angle of the mouth or, uncommonly, along the anterior margin of the sternocleidomastoid muscle (SCM).¹ These malformations are present at birth. It is usually located unilaterally in the preauricular region.^1,2 Accessory tragi may occur along the migratory line, as the auricle ascends from the neck area and their origin is the mandibular branchial arch.¹ Other auricular abnormalities are not usually associated with accessory tragus, since the majority of the external ear evolves from the second branchial arch.³ Bilateral AT development has been reported on the suprasternal region before.⁴ To our knowledge this is the first AT case that seen on the lateral cervical region bilaterally.

CASE REPORT

A four years old girl had skin-colored polypoid masses bilateral on the cervical region which had been present since birth. There was no significant family history of tragus or any other congenital deformities, and there were no neurologic or musculoskeletal abnormalities detected. There were bilateral, firm, skin-colored mass with an ovoid pedicle that was about 9×8×8 mm in size located on the right and 12×10×10 mm on the left cervical region (Figure 1). The AT lesions located bilaterally on the SCM anterior edge. At the right cervical region AT detected at the 1/3 inferior part of the anterior edge of the SCM and at the left side at the 1/3 superior part of the anterior edge of the SCM. It was completely removed by adequate excision and there has seen a cartilage in the center of the lesion (Figure 2). The histologic examination demonstrated mild orthokeratosis overlying the epidermis and numerous vellus hairs with sebaceous glands in papillary dermis. Centrally there was well-developed cartilage surrounded by the adipose tissue (Figure 3, 4).

We diagnosed the lesion as AT on the basis of clinicopathologic findings. There was no evidence of recurrence at a year post-operative follow-up visit.

DISCUSSION

Since the late 1800s, the AT has been described.¹ The lesion appears at birth as a small skin-colored papule or nodule. It may be solitary or multiple, unilateral or bilateral, pedunculated or sessile, and soft or firm. The size of the papule is usually 3 to 5 mm, and it might be covered with vellus hair.^2,3,5 AT, is usually an isolated developmental defect and not associated with other abnormalities.

Familial occurance of AT has been noted.^1,3 Two major conditions are commonly associated with AT: Goldenhar’s syndrome and Treacher Collins’ syndrome.^1,3 Embryologically, the auricle begins to develop from the first (mandibular) and second (hyoid) branchial arches at the fourth week of gestation. During the fifth and sixth weeks the first and second arches form six mesenchymal tubercles, the hillocks of His. Three hillocks appear on each arch and as they develop they fuse to form the structures of the auricle. As the mandible grows, the primitive auricle ascends from the lower lateral neck to the side of the head level with the eyes.^2,6 For this reason, AT is generally detected near the tragus but rarely on the cheek, the lateral neck along the anterior edge of the SCM, or the glabella or the suprasternal area.^2,4,7 Prevalance of the AT has been estimated to be aproximately 1,7:1,000.^1,3 Bilateral lesions are present in abaut 6% of cases, for a prevalance of between 9:1,000 and 10:100,000.¹

Several conditions may clinically mimic an AT: achrocordon, auricular fistula, fibroma, polyp, epidermoid cyst and wattles. So definitive diagnose can readily be established after histologic evaluation.¹

Here we present a unique case of AT in a 4 years old girl. These lesions were present at birth without any family history and had no other subjective symptoms. In the histological specimen there was well-developed cartilage surrounded by adipose tissue and dermoepidermal components. Therefore unusual occurance and distinctiveness, we report an AT case that developed on bilateral lateral cervical region.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

REFERENCES

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