A Case of Accessory Tragus on the Nasal Vestibule

Accessory tragus (AT) is diagnosed along with the documentation of its age of onset, characteristic anatomical site, and any findings of it containing pilosebaceous units and cartilaginous tissue within its central portion. AT is generally presented as a congenital skin-colored papule or nodule located anterior to the tragus, along an imaginary line drawn from the tragus to the angle of the mouth, or, uncommonly, along the anterior margin of the sternocleidomastoid muscle. It may feel soft on palpation and also be firm because of its underlying cartilage component. Here we present a unique case of AT in a 1 day old girl that developed on the nasal vestibule. It was surgically removed, including both the excess of skin and cartilage.

A 1-day-old Korean girl had a skin-colored polypoid mass on her nasal vestibule which had been present since birth. There was no significant family history of tragus or of any other congenital deformities, and there were no neurologic or musculoskeletal abnormalities detected. There was a solitary, soft, skin-colored mass with an ovoid pedicle that was about 8×8×8 mm in size located on the left nasal vestibule and a smaller skin-colored papule (its picture was not taken) on the left preauricular area (Fig. 1). Histologic examination of the lesion obtained from the nasal vestibule revealed, mild atrophic changes in the epidermis, multiple small hair follicles, abundant adipose tissue, and centrally well-developed cartilage surrounded by a connective tissue framework consisting of thick bundles of collagenous fibers in the dermis (Fig. 2). We diagnosed the lesion as accessory tragus (AT) on the basis of clinicopathologic findings. It was completely removed by adequate excision and was found to contain internal cartilage. There was no evidence of recurrence at a 24-month post-operative follow-up visit.

Fig. 1
A solitary, round, skin-colored, well-movable, firm nodule protruding from the left nasal vestibule.

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Fig. 2
(A) Accessory tragus with a central core of cartilage. (B) Multiple tiny hair follicles, sebaceous glands and eccine glands in the dermis. (C) A prominent connective tissue framework and cartilage surrounded by a thick fibrocollagenous sheath in the subcutaneous fat (H&E, A: ×15, B: ×40, C: ×40).

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Accessory tragus is a rare congenital malformation that was reported by Birkett for the first time in 1858. 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 hair1, 2. There are a few reports of familial AT and cases that result from maldevelopment of the first and second branchial arch3. AT, however, is usually an isolated developmental defect not associated with other abnormalities. 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 eyes4. 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 area5-7. We think that it is a remnant of the branchial cartilage derived from the first pharyngeal arch of embryonic life. Biopsy findings have shown a sessile or pedunculated polyp including multiple small hair follicles, fibrovascular tissue with fat lobules, central core of cartilage and prominent connective tissue framework5. These are the typical diagnostic clues for AT. Our case is distinctive in that we report an AT that developed on the nasal vestibule.