Structural changes and protein expression in the mastoid bone adjacent to cholesteatoma.
OBJECTIVE
Cholesteatoma of the mastoid and middle ear causes erosion of nearby bone. In this study we examined the mastoid bone adjacent to cholesteatoma and compared it with normal mastoid bone. In particular, noncollagenous proteins, which have a special structural and functional role in bone, were addressed.


METHODS
Nine mastoid specimens with cholesteatoma and four normal specimens obtained at surgery were examined.


METHODS
Histological and immunohistochemical methods were employed to evaluate the nature of structure and noncollagenous protein content changes in the mastoid bone affected by cholesteatoma.


RESULTS
The bone associated with cholesteatoma had structural changes as a noncontinuous periosteum, empty lacunae, irregular cement lines, and, specifically, the appearance of eosinophilic vesicles at the interface between the bone and cholesteatoma Immunohistochemistry demonstrated that noncollagenous proteins were apparently absent in the affected mastoid bone. Bone remote from the cholesteatoma seemed normal.


CONCLUSIONS
These findings demonstrate for the first time the changes in the noncollagenous protein content in the mastoid bone affected directly by cholesteatoma These changes could be a result of a direct influence of cholesteatoma-derived products on the osteoblast.
Cinamon
U
U
Department of Otoloaryngology--Head and Neck Surgery, The Chaim Sheba Medical Center, Tel-Hashomer, Israel.
Kronenberg
J
J
Benayahu
D
D
D000293:Adolescent; D000328:Adult; D002648:Child; D018424:Cholesteatoma, Middle Ear / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D016326:Extracellular Matrix Proteins / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008416:Mastoid / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged
D016326:Extracellular Matrix Proteins