[A case report for giant cholesteatoma occurred in 
fronto-parietal bone]

Cholesteatoma is a destructive and expanding growth benign tumor, mainly consisting of stratified squamous epithelium. It possesses the capacity of eroding bone and can exist in a nonaggressive state, remaining undetected for years. Once cholesteatoma appeared, it grows relentlessly and threats to invade intra-temporal structures. Most cholesteatomas occurred in the petrous bone and also affected the labyrinth and middle cranial fossa. Here, we report a preliminary wrongly-diagnosed case. The patient was wrongly diagnosed as "sebaceous cyst with infection" by local hospital. The definite diagnosis was made after the surgery performed by our department, which was confirmed by pathological result. So far, there were few reports of giant cholesteatoma which occurs in fronto-parietal part of skull with bone defect.