Introduction: Cholesteatomas of the middle ear are characterized by the presence of stratified squamous epithelium in this cavity presenting with highly invasive properties which may cause destruction of the bone and lead to complications. Substances such as cytokeratin (CK) 16 and Ki-67 are some of the markers of cellular proliferation and have been used to study this disease. CK 16 is a protein filament located in the cytoplasm of epithelial cells and typical of hyperproliferating epithelium. Ki-67 is a nuclear antigen found in cells that are in the proliferating stage. Aim: The objective of this research project was to study the expression of CK 16 and Ki-67 in acquired cholesteatomas. Study design: Clinical prospective. Material and Method: Samples were obtained from 31 patients submitted to otologic surgery for the removal of a middle ear cholesteatoma from 1998 to 2000. Twenty patients were adults and 11 were children. Samples were studied by histology and by immunohystochemistry for the expression of CK16 and Ki-67 in the matrix of the cholesteatoma. Results: CK 16 was found in the suprabasal layers of the matrix of the cholesteatoma, and Ki-67 was found from the basal layer all the way to the suprabasal and apical layers. Reaction to anti-CK 16 and Ki-67 antibodies was heterogeneous. There was a positive and significant relation between morphological variables such as epithelial acantosis and hyperplasia of the basal layer and the presence of suprabasal CK16 and Ki-67 in the matrix. Conclusion: Based on the results of this study, the authors conclude that cholesteatomas have hyperproliferating characteristics with a significant-expression of CK16 and Ki-67 in the matrix.
immunohystochemistry; cytokeratin; Ki-67 antigen; middle ear; cholesteatoma
