Cytokeratin expression in cholesteatoma matrix, meatal epidermis and middle ear epithelium. A preliminary report

The cytokeratin expression of cholesteatoma matrix, meatal epidermis and middle ear epithelium was investigated with six anticytokeratin monoclonal antibodies. One of these was broad specific and the other antibodies were directed against cytokeratins 4, 8, 10, 18 and 19 respectively. Immunoperoxidase staining of cryosections revealed the presence of cytokeratin 10 in cholesteatoma matrix and meatal epidermis. In contrast, middle ear epithelium was characterized by cytokeratins 4, 8, 18 and 19 and not by cytokeratin 10. An infrequent focal presence of cytokeratins 4, 18 and 19 was found in cholesteatoma. In general, the divergence between the cytokeratin expression of middle ear epithelium versus that of cholesteatoma and meatal epidermis suggests an epidermal origin of cholesteatoma. However, a metaplastic origin of cholesteatoma cannot be excluded because of the infrequent focal presence of cytokeratins 4, 18 and 19 in cholesteatoma.