Analysis of class II antigen expressing cells in cholesteatoma epithelium.

The present morphological study was designed to evaluate the significance of Langerhans cells in the pathogenesis of cholesteatoma. Biopsies of middle ear cholesteatomas were examined for Langerhans' cells expressing HLA-DR and anti-Leu 6 antigens by immunohistochemistry using monoclonal antibodies. No apparent difference in number of cells was observed when epithelium of cholesteatoma was compared with epithelium of healthy ear canals. Expression of HLA-DR antigens was detected on keratinocytes in Aspergillus flavus infected epidermis, used as a control tissue. This finding indicated an increased immunosurveillance of this tissue. However, no such expression of HLA-DR antigens was detected on epidermal cells of cholesteatomas. The results of the present study did not support the hypothesis of Langerhans' cells as having a primary role in the development of cholesteatoma.