Mediterr. J. Otol 2008; 4:(3)

Comparative Analysis of the Proliferative Activity of Cholesteatoma Epithelium
Jerzy Kuczkowski, Ewa Iżycka-Świeszewska, Alicja Bąkowska
Department Otolaryngology, Medical University of Gdańsk, Poland, jerzyk@amg.gda.pl

Background: The histopathological characteristics of cholesteatoma are hyperproliferation and differentiation of the epithelium. The proliferative capacity of cholesteatoma was studied through the kinetics of the epithelium of cholesteatoma. The present study was undertaken to compare the rate of proliferation and apoptosis using immunohistochemistry with PCNA antigen and p53 protein in cholesteatoma and skin of external auditory canal.

Material and methods: The expression and location of tissue PCNA and p53 were investigated in 29 samples of cholesteatoma and 8 skin specimens obtained during ear surgery. The tissues was fixed in formalin and embedded in paraffin for immunohistochemistry carried out using antibodies to PCNA and p53.

Results: Strong expression of PCNA was observed in spinous and granular layer of the epithelium in 41.4% cases of the cholesteatomas (mean positive rate 7.6 ±3.4). In the skin, PCNA was present only in single cells of the epidermis. Protein p53 was present in 14.7% of investigated samples of cholesteatoma (mean positive rate 13.8 ±2.2). The strongest expression of p53 was observed in the nucleus of the keratinocytes in granular layer of cholesteatoma epithelium. Presence of p53 in the skin was shown only in single cells of the epidermis.

Conclusions: Cholesteatoma epithelium is characterized by increased expression of p53 and PCNA. Proliferative activity is mainly observed in the granular layer of the epithelium of cholesteatoma. We observed an increase in the rate of proliferation and disregulation in the cholesteatoma epithelium when compared with normal skin of auditory canal.