C S Kim1, J W Chung. 1. Department of Otolaryngology, Seoul National University College of Medicine, Korea.
Abstract
HYPOTHESIS: Aural cholesteatoma has different morphologic and biologic characteristics from the normal epithelial cells. BACKGROUND: The exact pathophysiology of aural cholesteatoma has not been proved. There are certain factors that can be involved in the development of the aural cholesteatoma, which makes it necessary to find the morphologic and biologic changes in aural cholesteatoma. METHODS: The animal model of aural cholesteatoma was induced in gerbils with the external auditory canal (EAC) ligation method. Using immunohistochemical method, the distribution of cytokeratin and the binding patterns of lectin were observed to show the biologic and morphologic changes that take place in aural cholesteatomas. RESULTS: The successful induction rate was 86.7%. The cytokeratin distribution of aural cholesteatoma was similar to that of EAC but different from that of the middle ear mucosa. The cytokeratin distribution in the cholesteatoma did not change with the different duration of EAC ligation. The results of the lectin-binding study indicate that the mucin-type cells are mainly distributed in the suprabasal cells of aural cholesteatoma and that the basal cells of cholesteatoma lack a D-galactosyl sugar residue. CONCLUSION: This study suggests that the origin of aural cholesteatoma may be the external auditory canal epidermal cells, and the characteristics of these cells do not change once the cholesteatoma develops. This study also suggests that cholesteatoma has different biologic nature from that of the normal epithelial cell, especially in the basal cells.
HYPOTHESIS: Aural cholesteatoma has different morphologic and biologic characteristics from the normal epithelial cells. BACKGROUND: The exact pathophysiology of aural cholesteatoma has not been proved. There are certain factors that can be involved in the development of the aural cholesteatoma, which makes it necessary to find the morphologic and biologic changes in aural cholesteatoma. METHODS: The animal model of aural cholesteatoma was induced in gerbils with the external auditory canal (EAC) ligation method. Using immunohistochemical method, the distribution of cytokeratin and the binding patterns of lectin were observed to show the biologic and morphologic changes that take place in aural cholesteatomas. RESULTS: The successful induction rate was 86.7%. The cytokeratin distribution of aural cholesteatoma was similar to that of EAC but different from that of the middle ear mucosa. The cytokeratin distribution in the cholesteatoma did not change with the different duration of EAC ligation. The results of the lectin-binding study indicate that the mucin-type cells are mainly distributed in the suprabasal cells of aural cholesteatoma and that the basal cells of cholesteatoma lack a D-galactosyl sugar residue. CONCLUSION: This study suggests that the origin of aural cholesteatoma may be the external auditory canal epidermal cells, and the characteristics of these cells do not change once the cholesteatoma develops. This study also suggests that cholesteatoma has different biologic nature from that of the normal epithelial cell, especially in the basal cells.