Bone destruction due to the rupture of a cholesteatoma sac: A pathogenesis of bone destruction in aural cholesteatoma

Abstract

Severe bone destruction in a cholesteatoma is one of the characteristic clinical features. To clarify the mechanism of bone destruction in cholesteatoma, the matrix of cholesteatoma and the attached bone, obtained during middle ear surgery, was observed by light microscope. Rupture of the epithelial lining in a cholesteatoma and the escaping contents (keratin), which gave rise to intense characteristic granulations in subepithelial tissue, were found. Furthermore bone destruction was always found at the site of subepithelial tissue of cholesteatoma. From these facts, the escape of contents from the sac of cholesteatoma into the subepithelial layer is considered to be an important factor in the mechanism of bone destruction.

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.…”

“…detected abundant organic acids, including lactate and short‐chain fatty acids, in the keratin debris of cholesteatoma. Moreover, Kaneko et al . and Suzuki et al .…”

“…In the 1980s, Iino et al 47 detected abundant organic acids, including lactate and short-chain fatty acids, in the keratin debris of cholesteatoma. Moreover, Kaneko et al 40 and Suzuki et al 17 discovered that bone destruction is observed in the vicinity of the ruptured cholesteatoma epithelium, where keratin debris escapes through the epithelial break towards the subepithelial layer. Most recently, we have shown that the pH of the keratin debris of cholesteatoma was acidic, and the pH of the cholesteatoma epithelium was significantly lower than that of the antral mucosa.…”

Etiopathogenesis of acquired cholesteatoma: Prominent theories and recent advances in biomolecular research

“…The presence of bacteria may also prevent the cholesteatoma epithelium from activating terminal differentiation and returning to a quiescent state, thereby leading to ongoing proliferative, migratory, and invasive behaviors . In addition, the pH of the keratin debris of cholesteatoma has been found to be acidic, and the acidity of keratin debris escaped from the cholesteatoma sac has been proposed to be a critical factor in bone destruction . Researchers have proven that these acids are derived from aerobic (e.g., Staphylococcus aureus and Proteus species) as well as anaerobic (e.g., Peptococcus and Bacteroides species) microorganisms …”

Pathogenesis and Bone Resorption in Acquired Cholesteatoma: Current Knowledge and Future Prospectives

“…Areas of bone destruction could be seen at the site of rupture of cholesteatoma [54,55]. Hydroxyapatite, an inorganic bone component is highly insoluble under physiologic pH environment, but solubility dramatically increases as the pH is lowered [56].…”