Related Experiment Video
Updated: Aug 15, 2026

Endaural Endoscopic Atticoantrotomy (Retrograde Mastoidectomy) using a Constant Suction Bone-drilling Technique
Published on: May 23, 2021
Keratosis obturans and external auditory canal cholesteatoma
Abstract:
Keratosis obturans and external auditory canal cholesteatoma (EACC) have previously been considered to represent the same disease process. However, review of the literature and our cases reveal these to be two different clinical and pathological processes. Keratosis obturans presents as hearing loss and usually acute, severe pain secondary to the accumulation of large plugs of desquamated keratin in the ear canal. External auditory canal cholesteatoma presents as otorrhea with a chronic, dull pain secondary to an invasion of squamous tissue into a localized area of periosteitis in the canal wall. The treatment previously recommended for both of these conditions has been conservative debridement of the external canal and application of topical medication. While this remains the treatment of choice for keratosis obturans, surgery may be required to eradicate EACC.
Related Concept Videos
Hair Cells
The Cochlea
Unrenewable Cells
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer...
The Auditory Ossicles
The aptly named stapes look very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in...
Anatomy of the Ear
Auditory Pathway
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...

