Bone Resorption In Human Cholesteatoma: Morphological And Immunohistochemical Study

Objective:To observe the ultrastructure and morphology of eroded ossicles obtained during middle ear surgery for cholesteatoma.To observe the expression of receptor activator nuclear factor-KB ligand(RANKL) and osteoprotegerin(OPG) in cholesteatoma and to determine their roles in the destruction of bone .To investigate the mechanism of bone erosion and the role of osteoclast in cholesteatoma.Method:The morphology of auditory ossicles in 8 cholesteatoma samples and 2 normal samples were observed with light microscope. The ultrastructure of eroded ossicles in 9 cholesteatoma samples and 2 chronic otitis media samples were observed with transmission electron microscope, taking the bone of normal external auditory meatus in 2 cholesteatoma samples as the control. Immunohistochemical(sp) and the computer image quantitative analysis were used to examine the expression of RANKL and OPG in 27 samples from cholesteatoma and 11 normal cases.Result:1,The results of morphology(1)The results of light microscopeIn 8 cholesteatoma samples, the eroded auditory ossicles were surrounded with cholesteatoma.The total eroded surface adjacent to connective tissue. In 5 samples,Osteomyelitis,intramembranous and endochondral ossification were all observed, the obvious bone destruction and remodeling were observed coexistent. Several multinucleate osteoclasts with ruffled borders were observed in 2 samples.(2)The results of transmission electron microscopeIn 9 eroded ossicles from cholesteatoma samples,lots of leucocyte were observed in marrow in 7 samples., bacilli encroached in the local bone where collagen fibrils...