True about cholesteatoma is?

Essentially, cholesteatoma consists of two pas: (i) the matrix, which is made up of keratinizing squamous epithelium resting on a thin stroma of fibrous tissues and (ii) a central white mass, consisting of keratin debris produced by the matrix Cholesteatoma invades the surrounding structures from the middle ear first by following the path of least resistance and then by enzymatic bone destruction. Cholesteatoma has the propey to destroy the bone. Cholesteatoma is associated with the atticoantral type (also called unsafe or dangerous type) In tubotympanic type (safe or benign type), there is no risk of serious complications. Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 73, 74