CHOLESTEATOMA

Cholesteatoma is not a neoplasm but has locally aggressive behaviour
It can erode the ossicles and bony wall of inner ear
These lesions show increased expression of cathepsin and proliferation of squamous epithelium which may produce locally invasive growth
It can “closed” where it presents as cystic squamous mass or “open” where keratin squames are shed in middle ear cavity
Cholesteatomas are classified as Congenital or acquired
Congenital Cholesteatoma –
- Origin – results from epidermoid cell rests in developing middle ear
- Age – infants and young children
- Common site – Upper anterior middle ear
- Microscopy –
  - presents asclosed epidermoid cyst
  - Outer layer is formed by growing epithelium and cyst contains dead keratin squames
Acquired Cholesteatoma
- This is “open” ytpe and is associated with chronic otitis media
- Origin – arises fromthe squamous epithelium covering the external surface of the tympanic membrane
- grossly appear as yellow or pearly gray structures with corrugations
- Site – Begins in upper posterior part of middle ear but later fills most of the middle ear cavity
- Discharge occurs through pars flaccida of tympanic membrane mostly posteriorly
- Cholesteatoma extends into mastoid air cells and can damage one of the ossicle
- Retraction pockets are formed as a result of invagination of tympanic membrane into the
- Furrows are formed separating it into lobules
- Down growth from the epidermoid basal cells extend into surrounding tissue from the basal layer of cholesteatoma
- Microscopy
  - It shows 3 important features
    - kertain
    - Stratified squamous epithelium
    - Fibrous tissue or granulation tissue
  - Squamous epithelium shows down growth into the subepithelial connective tissue
  - cholesterol clefts and multinucleated foreign body giant cells can be present
  - Marked vascular congestion and abscess formation can also occur

References

Peter A. Humphrey and Rebecca D. Chernock. The Ear. In: The Washington manual of Surgical Pathology. By. Peter A. Humphrey, Louis P. Dehner, John D. Pfeifer. Chapter 7: Second Edition. 2016:97-103
Leslie Michaels. Ear. In Anderson’s Pathology. Tenth Edition. By: Ivan Damjanov, James Liner. Chapter 80.2876-2901

Cholesteatoma: Granulation tissue (left) with diffuse diffuse chronic inflammatory cells and congested blood vessels. Few multinucleated foreign body ginat cells and Keratin material (right) admixed with inflammatory cells are seen (H&E,X100)

Cholesteatoma: Granulation tissue with diffuse diffuse chronic inflammatory cells, multinucleated foreign body ginat cells and congested blood vessels are seen. (H&E,X100)

Cholesteatoma: Strip of keratinized squamous epithelium (left) and granulation tissue (right) with chronic inflammatory cells, multinucleated giant cells and congested blood vessels are seen. Anucleate squames and flakes of keratin are also present (H&E,X100)

Cholestaetoma: Section shows flakes of keratin, anucleate squames and hemorrhagic material with cholesterol clefts (upper) along with granulation tissue containing chronic inflammatory cells and multinucleated giant cells (lower right) (H&E,X100)

CHOLESTEATOMA

Cholesteatoma is not a neoplasm but has locally aggressive behaviour

It can erode the ossicles and bony wall of inner ear

These lesions show increased expression of cathepsin and proliferation of squamous epithelium which may produce locally invasive growth

It can “closed” where it presents as cystic squamous mass or “open” where keratin squames are shed in middle ear cavity

Cholesteatomas are classified as Congenital or acquired

Congenital Cholesteatoma –

Origin – results from epidermoid cell rests in developing middle ear

Age – infants and young children

Common site – Upper anterior middle ear

Microscopy –

presents asclosed epidermoid cyst

Outer layer is formed by growing epithelium and cyst contains dead keratin squames

Acquired Cholesteatoma

This is “open” ytpe and is associated with chronic otitis media

Origin – arises fromthe squamous epithelium covering the external surface of the tympanic membrane

grossly appear as yellow or pearly gray structures with corrugations

Site – Begins in upper posterior part of middle ear but later fills most of the middle ear cavity

Discharge occurs through pars flaccida of tympanic membrane mostly posteriorly

Cholesteatoma extends into mastoid air cells and can damage one of the ossicle

Retraction pockets are formed as a result of invagination of tympanic membrane into the

Furrows are formed separating it into lobules

Down growth from the epidermoid basal cells extend into surrounding tissue from the basal layer of cholesteatoma

Microscopy

It shows 3 important features

kertain

Stratified squamous epithelium

Fibrous tissue or granulation tissue

Squamous epithelium shows down growth into the subepithelial connective tissue

cholesterol clefts and multinucleated foreign body giant cells can be present

Marked vascular congestion and abscess formation can also occur

References

Peter A. Humphrey and Rebecca D. Chernock. The Ear. In: The Washington manual of Surgical Pathology. By. Peter A. Humphrey, Louis P. Dehner, John D. Pfeifer. Chapter 7: Second Edition. 2016:97-103

Leslie Michaels. Ear. In Anderson’s Pathology. Tenth Edition. By: Ivan Damjanov, James Liner. Chapter 80.2876-2901