Intractable retroauricular abscess associated with microtia and aural atresia--some views in relation to the congenital cholesteatoma and microtia.

Five microtic and aural atretic ears associated with intractable retroauricular abscess unresponsive to conservative treatment are reported. The pathogenesis of this abscess is primary cholesteatoma called "cholesteatoma auris congenita of atretic ear," and these lesions can be clearly explained by the embryological development of the external auditory meatus. Microtic ears with such lesions invariably have part of the cartilaginous canal patent but have an atrophic bony canal. Therefore, grade 3 microtia has never been affected theoretically. We also discuss the relationship between the retroauricular abscess and the development of the tympanic bone. The evaluation of this lesion with computed tomography is mandatory for the detection of an occult congenital cholesteatoma behind the atretic canal, and regular follow-up of the patients with microtia and aural atresia is necessary for plastic surgeons.