I. Srebniak Management of External Auditory Canal Cholesteatoma

External ear canal cholesteatoma (EAC) is a rare destructive lesion within temporal bone and may occur in 1:1000 new patients with ear diseases [1, 3]. EAC cholesteatoma was first described by Toynbee in 1850. Since that time, it had confused to keratosis obturans. First description of keratosis obturans was presented by Piepergerdes et al., in 1980 [6]. Keratosis obturans (KO) is a similar to EAC cholesteatoma but separate condition. KO is a plug of cerumen and keratin that occludes the entire ear canal and that cases widening of the bony EAC. In contrast to EAC cholesteatoma, which begins in the inferior part of the bony EAC, keratosis envolves the entire circumference of the ear canal and it is frequently bilateral [5]. It occurs in younger patients and so often associated with sinusitis and bronchiectasis. The most common complaints in KO are hearing loss and pain full occlusion [6, 8]. KO is a external ear canal skin disease that may destroy a tympanic membrane, spread into the middle ear cavity and always accompanied by inflammation [8]. Clinically EAC cholesteatoma has the same appearance as middle ear cholesteatoma – a pearlescent ball of skin, more often with surrounding inflammation or granulation tissue. It always involves the inferior part of the ear canal, although it may grow to fill the entire canal [2]. On computed tomographic (CT) imaging, bony erosion of the inferior bony ear canal will usually be seen [3]. In cases with spreading to the mastoid cells, tympanic membrane is often intact and undamaged, a lesion is extending to mastoid due to posterior bony wall of external ear canal destruction and lysis [8]. We used Naim et al. (2005) EAC cholesteatoma classification [4]. This classification is based on histological findings and clinical symptoms. It is known that the cause of congenital EAC cholesteatoma is stenosis of EAC and of spontaneous EAC cholesteatoma is uncertain [12]. The aim of research was to investigate cholesteatoma activity in patients with acquired EAC cholesteatoma based on clinical data, otomicroscopy and high resolution CT scans findings, proteolytic enzymes activity study in middle ear effusion, cholesteatoma matrix and adjacent bone.