Mastoid cavity obliteration by bone pate and cartilage - a comparison

Otitis Media is a multifactorial, multifaceted disease that manifests itself in the middle ear, mastoid and the eustachian tube. It is the result of prevailing aggression over the immune defenses of the body. Cholesteatoma is an abnormal accumulation of keratin-producing squamous epithelium in the middle ear, epitympanum, mastoid or petrous apex, which has a three dimensional structure exhibiting independent growth, replacing middle ear mucosa and resorbing underlying bone. Histologically, it is made up of keratinizing squamous epithelium made up of 3 components i.e. the cystic content, the matrix and the perimatrix. The cystic content is made up of fully differentiated anucleate keratin squames. The matrix contains the keratinizing squamous epithelium lining and the perimatrix, contain granulation tissue with cholesterol crystals. The perimatrix is in contact with the bone and it is this granulation tissue which produces proteolytic enzymes which result in bone destruction. The biological hallmarks of cholesteatoma are its invasiveness, unrestrained proliferation, aggressiveness and recidivism.