Fig. 4
Photomicrograph of the tympanokeratoma eroding the temporal bone. In the left ear focal bony erosion of the petrous portion of the temporal bone is evident subjacent to the tympanokeratoma (arrows). Abundant inflammatory cells are present in the cochlea (c). Marked mucoperiosteal fibrosis, pseudogland formation and collections of cholesterol clefts are found within the remainder of middle ear compartment (m) surrounding the incus (i) and stapes (s). The stapes remains anchored in the vestibular (oval) window (arrowheads) supporting spread to the internal ear did not occur through the vestibular window. Inset (square): Marked mucoperiosteal fibrosis, pseudogland formation and collections of cholesterol clefts in the middle ear. Haematoxylin and eosin stain, bar: 2 mm