Experimental Aural Cholesteatoma Causing Bone Resorption

Abstract

A series of experiments were carried out on 55 guinea pigs in four groups to study the conditions fostering bone resorbin epidermal cysts. The first group had free grafts of canal wall skin applied to the cochlea with and without talc application. The second group had canal skin flaps applied to the cochlea with and without subsequent talc application. The third group had talc applied either to the tympanic membrane or on the cochlea. The fourth group had a canal skin flap inserted into a mucosal pocket in the bulla. The animals were killed three to four months after surgery and the temporal bones were prepared for histology. Epidermal cysts were found at the cochlea in 8 of 55 animals. Cochlear fistulas were found in 6 of 55 animals. The fistulas were associated with epidermal cysts in three cases, otitis media in two cases, and talc granuloma in one case. These experiments show that migrating skin attached to a source of epithelium is capable of inducing bone resorption. Chronic foreign body granulomas and chronic sepsis are also capable of resorbing bone. These three conditions all produce a layer of undifferentiated connective tissue containing chronic inflammatory cells lying against the resorbing bone.

Comparação da espessura da perimatriz, de colesteatomas adquiridos, entre pacientes pediátricos e adultos

“…Based on Lazarus et al 24 findings that stated that the chemical activity of the perimatrix had a role in bone absorption, Gantz et al 25 demonstrated that inflammatory mononuclear cells produce collagenolytic enzymes. The importance of the perimatrix in bone reabsorption is also pointed out by Abramson et al 26 and it is the first to suggest that the potential of infiltration of cholesteatoma would be related with chemoenzymatic activity of perimatrix.…”

Increased permeability of the epithelium of middle ear cholesteatoma

“…33 On the other hand, Harris found few osteoclasts in cholesteatoma lesions. 34 This negative result on the occurrence of osteoclasts was confirmed in the 1970-1980s by a number of studies, [35][36][37][38][39][40][41][42][43][44][45] while only a few reports have supported the presence of osteoclasts in cholesteatoma. 46 These lines of evidence indicate that the presence and participation of osteoclasts in cholesteatoma lesions remain controversial and unclear.…”

Facial Nerve and Medially Invasive Petrous Bone Cholesteatomas

“…Enzymes appear to digest collagen and demineralize the bone. 11 More typical is a pushing border with a lateral semicircular canal fistula that allows matrix removal. Extensive cholesteatomatous involvement of the labyrinth has been previously reported.t-s In extensive erosion of the otic capsule, large areas are typically dissolved over a broad front of disease.…”