Cholesteatoma and Chronic Otitis Media | Cholesteatoma

Summary

This video lecture explores cholesteatoma (chestoa), a condition involving the growth of keratinizing squamous epithelium in the middle ear or mastoid. It covers its origin theories, including congenital cell rests, invagination of the tympanic membrane, and basal cell hyperplasia. The lecture differentiates between congenital, primary acquired, and secondary acquired cholesteatomas, detailing their causes and classifications. It also discusses how cholesteatoma expands, leading to bone destruction through enzymatic activity, and the potential complications, such as hearing loss, vertigo, and facial nerve paralysis, that arise from these processes.

Takeaways

• 😀 Chesta refers to the presence of keratinizing squamous epithelium in the middle ear or mastoid, which can lead to various complications.
• 😀 Chesta consists of two parts: keratinized squamous epithelium resting on a thin fibrous tissue stroma (the Matrix), with a central keratin mass.
• 😀 There are several theories regarding the origin of chesta, including congenital cell rests, invagination of the tympanic membrane, basil cell hyperplasia, epithelial invasion, and metaplasia.
• 😀 Chesta can be classified into congenital or acquired types, with congenital chesta arising from embryonic epidermal cell rests in the middle ear or temporal bone.
• 😀 Primary acquired chesta occurs without a history of previous otitis media or perforation, often resulting from invagination, basil cell hyperplasia, or squamous metaplasia.
• 😀 Secondary acquired chesta is associated with pre-existing perforation or otitis media, which can lead to epithelial migration and metaplasia.
• 😀 The formation of primary acquired chesta can result from obstruction of the Eustachian tube or infection in the middle ear, which causes retraction pockets and cellular changes.
• 😀 Secondary acquired chesta often involves migration of epithelial cells through perforations or persistent otitis media, which leads to metaplasia and hyperplasia.
• 😀 The expansion of chesta can result in the destruction of surrounding bone due to the action of enzymes such as collagenase and acid phosphatase.
• 😀 Chesta can lead to significant complications, including hearing loss, vertigo, facial nerve paralysis, and erosion of the bony labyrinth and other structures in the ear.
• 😀 The spread of chesta and the destruction of bone structures involve enzymes that cause damage to tissues and invade the middle ear, leading to severe complications.

Q & A

What is cholesteatoma?

Cholesteatoma is the presence of keratinized squamous epithelium in the middle ear or mastoid. It consists of keratinized squamous epithelium resting on a fibrous tissue matrix, along with a central mass of keratin.

What are the theories regarding the origin of cholesteatoma?

There are several theories for the origin of cholesteatoma, including: congenital cell rests, the invagination of the tympanic membrane, basal cell hyperplasia, epithelial invasion, and metaplasia.

What are the different classifications of cholesteatoma?

Cholesteatoma can be classified into congenital and acquired types. Congenital cholesteatoma arises from embryonic epidermal cell rests in the middle ear or temporal bone, while acquired cholesteatomas are further divided into primary acquired and secondary acquired.

How is congenital cholesteatoma different from acquired cholesteatoma?

Congenital cholesteatoma is present at birth and originates from embryonic epidermal cell rests. Acquired cholesteatoma occurs later in life and can be classified as primary (without previous ear conditions) or secondary (due to pre-existing conditions like perforations or otitis media).

What are the characteristics of primary acquired cholesteatoma?

Primary acquired cholesteatoma occurs without a history of previous otitis media or perforation. It can result from invagination of the tympanic membrane, basal cell hyperplasia, or squamous metaplasia.

What is the role of the Eustachian tube in the development of primary cholesteatoma?

Obstruction of the Eustachian tube leads to negative pressure in the middle ear, causing the formation of a retraction pocket. This pocket may eventually lead to the development of primary acquired cholesteatoma.

What causes secondary acquired cholesteatoma?

Secondary acquired cholesteatoma develops from pre-existing conditions like otitis media or perforations in the tympanic membrane. It is often associated with epithelial migration or metaplasia through the perforation.

How do infections contribute to the development of primary acquired cholesteatoma?

Infections in the middle ear can lead to two changes: basal cell hyperplasia (excessive growth of basal cells) and squamous metaplasia (change in cell type), both of which contribute to the formation of primary acquired cholesteatoma.

What enzymes are involved in the destruction of bone in cholesteatoma?

Collagenase, acid phosphatase, and other proteolytic enzymes are responsible for the destruction of bone in cholesteatoma. These enzymes break down collagen and bone, leading to the erosion of surrounding structures.

What complications can arise from the spread of cholesteatoma?

Cholesteatoma can cause serious complications, including hearing loss, vertigo, and facial nerve paralysis. This occurs due to the destruction of bone and invasion of surrounding structures like the inner ear, facial nerve, and ossicles.