Localisation of basic fibroblast growth factor in cholesteatoma matrix: an immunochemical study.

Objective. To investigate the expression of basic fibroblast growth factor in the matrix of human acquired cholesteatoma compared to the deep meatal skin. This topic does not appear to have been fully investigated before. Methods. An immunochemical study was conducted. Cholesteatoma tissues from adult patients were collected during surgery (n = 19). Control specimens were taken from the deep meatal skin (n = 8) and compared. Results. A highly significant difference in basic fibroblast growth factor expression was identified between cholesteatoma and skin (mean +/- standard error = 58.53 +/- 3.6 per cent in cholesteatoma vs 40.6 +/- 3.5 per cent in skin; p = 0.005). Both basal and parabasal keratinocytes were stained positive with basic fibroblast growth factor. Additionally, there was specific staining in the basal columnar middle-ear epithelium and mast cell membrane. Conclusion. Basic fibroblast growth factor plays an active role in proliferative activity of cholesteatoma through its overexpression in basal and parabasal layers of cholesteatoma matrix. Moreover, its expression in the mast cell membrane supports its role in bone resorption activity.