Diseases of The Middle Ear
True about cholesteatoma is/are: (LQ)
|A||It is a benign tumour|
|B||Metastasizes to Iymphnode|
|D||Erodes the bone|
a. Normally middle ear is not lined by keratinising squamous epithelium. If keratinising squamous epithelium is present anywhere in the middle ear or mastoid, it is called as cholesteatoma.
b. The term cholesteatoma literally means - "Skin in the wrong place." It is a misnomer because neither it contains cholesterol crystals nor it is a tumor."
Cholesteatoma has 2 parts:
Matrix: made of keratinising squamous epithelium.?
Central white mass - made of keratin debris. Hence also k/a epidermosis or keratoma - Cholesteatoma has the property to destroy bones (due to the various enzymes released by it and not by pressure necrosis).