p53 Expression and keratinocyte hyperproliferation in middle ear cholesteatoma.

Keratinocytes in middle ear cholesteatoma have hyperproliferative properties. There is controversy regarding the role of p53 and its effect on cellular proliferation in cholesteatoma. This study was instituted to examine this. Cholesteatoma and deep meatal skin control specimens were analysed for MIB-1 (n = 7, controls = 7), a marker of cellular proliferation, and p53 (n = 17, controls = 17) expression by immunocytochemistry. Expression of p53 was minimal or absent in both cholesteatoma and controls (P = 0.2). MIB-1 expression was higher, but not significantly so, in cholesteatoma than in controls (P = 0.09). Our study has shown no significant p53 expression in cholesteatoma epithelium. This suggests that there is no dysfunction in the p53-mediated cell cycle control mechanisms in cholesteatoma.