The morphological study of eroded auditory ossicles by cholesteatoma
MA Yanli YE Shengnan(Department of Otolaryngology,the First Affiliated Hospital of Fujian Medical University, Fuzhou , 350005,China)
Objective:To observe the morphology of eroded auditory ossicles obtained in middle ear surgery for cholesteatoma and to investigate the mechanism of bone erosion in cholesteatoma.Method:The morphology of eroded auditory ossicles in 8 cholesteatoma cases and 2 normal cases were observed with light microscopy. The ultrastructure of eroded auditory ossicles in 5 cholesteatoma cases and the ultrastructure of control bones in external ear canal of 2 cases were observed and compared with transmission electron microscopy.Result:Osteomyelitis and multinucleate osteoclasts with ruffled borders were observed in the eroded auditory ossicles of cholesteatoma. Intramembranous and endochondral ossification were both observed. The obvious bone destruction and remodeling were observed coexistently.Conclusion:Osteoclasts and Osteomyelitis are both responsible for bone destruction in cholesteatoma. Intramembranous and endochondral ossification may co-participate in bone remodeling. Osteogenesis is also a basic pathologic phenomena in cholesteatoma. The obvious bone destruction and remodeling can coexist in cholesteatoma cases.