A girl aged 2 years with no history of interest presented with an elastic painless mass measuring 2 cm in diameter at the level of the concha in the left ear lobe, with normal appearance of the skin (Fig. 1A) that had been growing progressively in the past 7 months. The otoscope exam was normal in both ears.
The management was surgical, with complete resection of the lesion, which turned out to be an encapsulated cystic structure (Fig. 1B). In two years of follow-up, there have been no signs of recurrence, and the cosmetic outcome has been excellent (Fig. 1C).
The findings of the histological examination were consistent with dermoid cyst (Fig. 2A and B), of two sections stained with haematoxylin and eosin, one revealed a cystic lesion filled with anucleate keratin fragments, and the other a pilosebaceous unit in the cyst wall.
Dermoid cysts are benign congenital tumours that develop in the early years of life, 70% of which are diagnosed by age 5 years. Histologically, they feature a capsule of keratinised squamous epithelium containing fragments of keratin and skin adnexa. Seven percent are found in the head and neck (80% at the orbital/periorbital level). Ear involvement is rare, with fewer than 30 cases described in the literature, most at the base or behind the ear, and exceptionally in the ear lobe.1–3
The differential diagnosis mainly includes epithelial cysts, which are more frequent in the ear lobe and external ear and have the same macroscopic appearance. They can be congenital or acquired and only contain keratin.3 The management is always surgical due to the risk of malignant transformation.1
