The proliferative capacity of the keratinizing annular epithelium

Using monoclonal antibodies specific for CK chains and the indirect immunoperoxidase technique, the expression of 10 CK polypeptides was investigated. The external stratified squamous epithelium of the tympanic membrane generally expressed CKs 5, 10 and 14. In addition, basal keratinocytes in the annular region, both tympanic and deep meatal, expressed CK19 (a simple epithelium marker). Suprabasally the hyperproliferative marker CK16 (known to have a limited distribution in healthy epidermis) was expressed in the same area. These data reflect the unusually proliferative nature of this transitional area.