Cholesteatoma is also known as epidermoid cyst and pearloma. It is currently considered to be a benign tumor with a congenital lack of blood vessels originating from the ectopic embryonic remnants of ectodermal tissue. Cholesteatomas are found in the brain and ear. Depending on the location of the cholesteatoma, it can be classified as intracranial cholesteatoma, external auditory canal cholesteatoma, and cholesteatoma otitis media. It is generally believed that the incidence of intracranial cholesteatoma is 0.5-1.8% of whole brain tumors. They can be multiple and range in size from a few millimeters to several centimeters. Most cholesteatomas are surgically removed. The incidence of intracranial cholesteatoma is generally considered to be 0.5-1.8% of all brain tumors. They can be multiple and range in size from a few millimeters to several centimeters. They can develop at any age, with a peak age of 40 years. Men are slightly more common than women, with a ratio of 1.25:1. Most tumors develop in adulthood, with the most common cases occurring between the ages of 20 and 50, accounting for more than 70% of cases. It may be associated with dermal fistula, spina bifida, spinal cord cavernosa, and skull base depression. The cause of external auditory canal cholesteatoma is unknown, but it may be due to chronic congestion of the skin of the external auditory canal due to long-term stimulation by various pathologies (e.g. cerumen embolism, inflammation, foreign bodies, fungal infections, etc.). This causes active growth of basal cells in the hair layer of the local skin and abnormal increase in the shedding of keratinized epithelial cells. Over time, its center decays, decomposes, and denatures, producing cholesterol crystals. Cholesteatoma of the external auditory canal can be complicated by cholesteatoma mastoiditis of the middle ear, which can also cause peripheral facial paralysis. Cholesteatoma-type otitis media is often closely related to chronic significant suppurative otitis media. When the middle ear is inflamed with long-term pus flow, the tympanic membrane is corroded by pus and perforated, and many times the epidermis of the external auditory canal easily enters the middle ear cavity and mastoid cavity along the perforation. Its epithelial layer keratinizes, repeatedly sheds, accumulates, and compresses the surrounding bone, causing it to absorb and form a cavity. The bacteria multiply and correctly produce lactic acid, which further erodes the surrounding bone and leads to the spread of reoccurring inflammation. As the left and right middle ears and mastoid process, which are the preferred sites, the pressure increases with the increase of cholesteatoma body, and once the bone wall is punctured, the pus and bacteria can enter the skull through it, and serious intracranial complications such as dural abscess, sigmoid sinus thrombophlebitis, septic meningitis and brain abscess can occur. The diagnosis of cholesteatoma can be made by CT and MRI, but the gold standard for diagnosis is still the pathological examination results. Since the tumor is benign, postoperative recovery is generally good. If a major resection is achieved, recurrence is usually late and can be delayed for several years or even decades. Long-term postoperative follow-up has been reported, with survival of more than 20 years up to 92% and postoperative mortality rate of 2-11%, the main cause of death being intracranial infection. Recent data from several groups of microsurgery have shown that the operative mortality rate has been reduced to less than 1%. Because of the nonrenewable nature of the nervous system, cholesteatoma resection is intended to prevent further neurological damage, and surgery may not undo existing neurological deficits. For intracranial cholesteatoma, there are no clear recommendations for prevention. For patients who have undergone surgical treatment and have a pathologically confirmed diagnosis, periodic imaging review is required for early detection of tumor recurrence.