Dermal inclusion cysts are benign masses that arise as the result of the entrapment of ectodermal components during embryogenesis. Their presenting symptoms are a direct result of the mass effect of the growing cyst. We describe the case of a 23-month-old girl who presented with a single, large dermal inclusion cyst in the external auditory canal. Our review of the literature revealed that only 2 other cases of a dermal inclusion cyst in this location have been previously reported.
Dermal inclusion cysts-also called dermoid cysts or simply dermoids-are rare, benign, developmental lesions. While they present during a wide range of ages, they are believed to be of congenital origin.1 The contents of these cysts include hair, squamous epithelium, and glandular tissue. Presenting symptoms are primarily attributable to the mass effect. A cyst might rupture and cause infection and inflammation.2