R445 – Expression of Proliferative Markers in Cholesteatoma

Abstract

Problem Cholesteatoma is characterized by the presence of a squamous epithelium invading the middle ear altering its growth properties. This epithelium believed to have hyperproliferative properties. Inflammatory stimulation of the underlying connective tissue, as well as an autocrine mechanism, may be responsible for the dysregulation and abnormal proliferative feature of the keratinocytes in cholesteatoma. Methods Comparative investigations were performed to assess the epithelial cell kinetics of cholesteatoma and auditory meatal skin. Monoclonal antibody PCNA and Ki-67 immunohistochemical staining were applied. Results Specimens of cholesteatoma samples (n=30) showed an average PCNA score of 26.6% and an average Ki-67 score of 15.9%. Auditory meatal skin(n=8) revealed an average PCNA score of 8.2% and average Ki-67 score of 4.9%. The results of this study confirm a highly increase in the proliferation rate of cholesteatoma keratinocytes, which had an PCNA score that was 3.24 times higher than the score for keratinocyte of auditory meatal skin and Ki-67 score of cholesteatoma was 3.24 times higher than auditory meatal skin. Conclusion We conclude that cholesteatoma is a hyperproliferative activity and that PCNA and Ki-67 immunohistochemical staining are valuable tool for assessing cell kinetics in cholesteatoma. Significance The cholesteatoma possesses a variable degree of proliferative activities depending on its histologic composition. The formation and accumulation of the keratin due to the continuous epithelial growth probably are important elements in inducing the inflammation.