[Expression of 4F2-activation antigen in middle ear cholesteatoma]

Cholesteatoma consists of a keratinising squamous epithelium in the middle ear cavity. The human 4F2 antigen appears at the end of the phase G0 and at the beginning of the phase G1, remaining detectable throughout mitosis. This antigen is therefore considered to be an activation marker. In this study the presence and distribution of 4F2 in the cholesteatoma epithelium was investigated using monoclonal antibodies and the alkaline-phosphatase-anti-alkaline-phosphatase method. Normal skin showed positive immunostaining exclusively in the basal keratinocytes. In contrast, all cholesteatomas showed a suprabasal expression of the 4F2 antigen. The results confirm the hyperproliferative character of cholesteatoma epithelium.