Accessory tragus on the nasal vestibule: A rare case report with literature review

Dear Editor,

Accessory tragus (AT) is a congenital pedunculated or sessile, skin-colored papule or nodule, most often unilateral and solitary. The papule size is usually 3–5 mm and might be covered with vellus hair. Diagnosis is based on the age of onset, the clinical appearance of the lesion, and the characteristic anatomical location anterior to the tragus. However, uncommonly, accessory tragi may appear at unusual sites.^1,2

A 21-year-old male presented with a solitary, roughly spherical, 6 × 4 mm, soft, and skin-colored mass with a short pedicle located on the left nasal vestibule since birth [Figure 1a]. There was no history of consanguinity nor family history of similar cases. The patient was otherwise healthy without any system abnormalities. The patient wanted to remove the lesion for cosmetic purposes; however, he refused complete surgical excision, so the lesion was shaved by a scalpel, followed by cauterization of the base [Figure 1b], and then sent for histopathologic examination that revealed undulated epidermis with basket-weave hyperkeratosis, mild papillomatosis, and focal increase in basal melanin. The dermis showed loose collagen bundles and fat lobules occupying the central core [Figure 1c]. Based on history and clinicopathological findings, the diagnosis was AT.

Close

Figure 1:

(a) Clinical appearance of accessory tragus on the left nasal vestibule in the form of a solitary, soft, and skin-colored nodule, (b) immediately after the lesion was shaved and the base was cauterized, and (c) histopathology of the excised specimen showing surface epithelium and a dermal core of numerous fat lobules and loose collagen bundles (hematoxylin and eosin, × 4).

Export to PPT

AT is a malformation that almost exclusively is located in areas derived from branchial arches, most commonly the preauricular area. Less common locations of AT include the cheek in an area extending along an imaginary line drawn from the angle of the mouth to the ear, as well as the lateral neck anterior to the sternocleidomastoid muscle.¹

Embryologically, the auricle develops from the first and second branchial arches in the 4^th week of gestation. During the 5^th and 6^th 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. For this reason, AT is generally detected near the tragus but rarely on the cheek, the lateral neck along the anterior edge of the sternocleidomastoid muscle, or the glabella or the suprasternal area.³

Outside these predilection areas, accessory tragi are rarely encountered in the skin. Only three previous cases were located on the nasal vestibule,^2-4, and they were summarized in Table 1.

There are a few reports of familial AT.³ It is usually an isolated developmental defect not associated with other abnormalities. However, AT may rarely be associated with other genetic syndromes such as Wolf-Hirschhorn, Treacher-Collins, vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities (VACTERL), Goldenhar, and Townes-Brooks. In addition, it can also be associated with hearing impairment and renal abnormalities such as horseshoe kidney and hydronephrosis.⁵

Biopsy findings have shown a sessile or pedunculated polyp, including multiple small hair follicles, fibrovascular tissue with fat lobules, a central core of cartilage, and a prominent connective tissue framework.³ These are the typical diagnostic clues for AT. Our case is distinctive because we report an AT developed on the nasal vestibule. Furthermore, cartilage could not be identified histopathologically in our case by examining serial sections, which is not necessarily uncommon in cases of AT.⁶

Management includes complete lesion excision with relevant investigations to rule out other congenital abnormalities.⁴ In our case, the lesion healed perfectly with no evidence of recurrence at a 6-month follow-up visit.