[The expression of receptor activator nuclear factor-kappaB ligand and osteoprotegerin in cholesteatoma].

To observe the expression of receptor activator nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) in cholesteatoma and to determine their roles in the destruction of bone. To observe the role of osteoclasts in bone destruction.Immunohistochemical technique and computer image analysis were used to examine the expression of RANKL and OPG in 27 cholesteatoma and 11 normal tissue respectively.RANKL was expressed mainly in promatrix cells, including fibroblasts and foam cells. OPG was expressed both in epithelium and promatrix cells. The results of the computer image quantitative analysis showed that the mean optical density of RANKL and the ratio of RANKL/OPG in cholesteatoma were higher than that in normal skin epithelial tissue (P<0.05). There was no significant difference between the mean optical density of OPG in cholesteatoma and that in normal skin epithelial tissue (P>0.05).The overexpression of RANKL and the increased ratio of RANKL/OPG in cholesteatoma are associated with the destruction of bone. Osteoclasts is possible mediator of osteolysis.