With disease progression, otodystrophic damage of the cochlea results in generalized retrofenestral or
cochleariform otosclerosis.
This otoendoscopic photograph shows the near total tympanic perforation and mesotympahnic structures, including the round window niche, the pyramidal process with stapedial muscle tendon, the facial nerve, the
cochleariform process, and ossicular chain.
It runs posterior-superior to the
cochleariform process, superior and lateral to the oval window, and then inferior to the lateral semicircular canal.
The lesion had extended from slightly below the level of the pyramidal process to just anterior to the
cochleariform process; it did not extend below the level of the umbo.
Exploration of the middle ear revealed a well-encapsulated cholesteatoma abutting the tympanic membrane, promontory, malleus,
cochleariform process, tensor tympani tendon, and bony annulus.
A second plaque of tympanosclerosis was seen medial to the neck of the malleus, bridging the gap between it and the
cochleariform process and extending to the chorda tympani nerve.