What is one characteristic feature of cholesteatoma?

Cholesteatoma is characterized by abnormal epithelial growth. It forms as a result of skin cells and other debris accumulating in the middle ear or mastoid process due to a chronic negative pressure in the ear, often following repeated infections or eustachian tube dysfunction. This abnormal growth can lead to the destruction of surrounding structures and can cause hearing loss, as well as other potential complications.

While fluid-filled sacs, ongoing infections, and cystic masses may be associated with other ear conditions or complications, they do not define cholesteatoma itself. The key characteristic is the invasion of the epithelial tissue, which is significant for the diagnosis and management of this condition.