Cholesteatoma is a benign skin growth arising in an abnormal location like the middle ear behind the eardrum usually occurring as a result of frequent infections in the ear leading to conductive hearing loss.

Otoscopic examination is the most effective technique to aid diagnosis of cholesteatoma. High-resolution CT scanning is used to confirm diagnosis based on physical examination and can also determine the severity of the condition. Magnetic Resonance Imaging (MRI) is used preoperatively in planning surgical treatment to create a clearer of the position of the skin overgrowth.

Initial treatment approaches for cholesteatoma include ear cleaning, administration of antibiotics, and ear drops. Larger cholesteatoma normally necessitates surgery to remove the skin growth to facilitate restoration of hearing.

Symptoms of cholesteatoma include ear drain usually with a foul-smelling odor, pressure in the ear which causes pain behind or in the ear, muscle weakness felt on the affected side of the face sometimes combined with a dizzy sensation. If left untreated, the infection will spread to the inner ear and the brain leading to more serious conditions such as deafness, brain abscess, meningitis, and worse, may even result to death.

Frequent ear infections are the cause of skin in-growth over the eardrum; however there are also cases of cholesteatoma present at birth (congenital).