CHOLESTEATOMA

Moderator-Dr.MohanPresenter-Dr.Razal

Definition • The term coined by Johannes Muller in 1838. • defined as a cystic structure filled with

desquamated squamous debris lying on fibrous matrix.(skin in wrong place)

Currently the Definition is, A three dimensional epidermoid structure Exhibiting independent growth Replacing the middle ear mucosa and resorption

of the underlying bone.

Histologically• Cystic Content

o is composed of fully differentiated anucleate keratin squames.

• Matrix o contains keratinizing squamous epithelium lining a cyst

like structure. • Perimatrix

o known as lamina propria o peripheral part of cholesteatoma consists of granulation

tissue and cholesterol granules. o This layer is in contact with the bone. It is the granulation

tissue which releases enzymes that cause bone destruction.

Cholesteatoma

Classification Can be classified as,• Congenital cholesteatoma

• Acquired cholesteatoma. o Primary acquired cholesteatoma o Secondary acquired cholesteatoma

Primary acquired• Etiology unknown• there is no history of preexisting or previous

episodes of otitis media or perforation. Lesions just arise from the attic region of the middle ear.

• Various theories have been proposed to explain the pathophysiology

Pathophysiology Cawthrone theory:• suggested by Cawthrone in 1963 • that cholesteatoma always originated from

congenital embryonic cell rests present in various areas of the temporal bone.

PathophysiologyTumarkin’s theory: • cholesteatoma is derived by immigration

of squamous epithelium from the deep portion of the external auditory canal into the middle ear cleft through a marginal perforation or a total perforation.

Pathophysiology Toss theory of invagination: • persistent negative pressure in the attic

region causes invagination of pars flaccida causing a retraction pocket.

• This retraction pocket becomes later filled with desquamated epithelial debris which forms a nidus for the infection to occur later.

• Common organisms to infect this keratin debris are Psuedomonas, E. coli, Proteus etc.

Retraction pockets

• A retraction pocket is an invagination of the tympanic membrane. The negative middle ear pressure, which is the cause of retraction pocket

• Toss classified attic retraction pockets into 4 grades:

• Grade I: The pars flaccida is not in contact with the neck of the malleus.

• Grade II: The retracted pars flaccida is in contact with the neck of the malleus and clothing it.

• Grade III: Here in addition to grade II features there is minimal erosion of the outer attic wall

• Grade IV: In this grade in addition to all the above said changes there is severe erosion of the outer attic wall or scutum.

Pathophysiology Metaplasia:• This theory was first suggested by Wendt in

1873.• The epithelium in the attic area of the

middle ear undergoes metaplastic changes in response to subclinical infection.

• This metaplastic mucosa is squamous in nature there by forming a nidus for cholesteatoma formation in the attic region.

Pathophysiology Habermann’s epithelial invasion theory: • This theory suggests that following

perforation of the tympanic membrane, epithelium invades into the attic area.

Secondary acquired• This always follows active middle ear infection

which destroy the tympanic membrane along with the annulus.

• The destruction of annulus predisposes to epithelial migration from the external auditory canal into the attic region

Pathology• Necrosis of tympanic membrane tissue along with

its annulus. caused due to the virulence of the organisms involved i.e. beta-hemolytic streptococci.

• Necrosis starts to occur in those areas of ear drum which have the poorest blood supply.

Congenital Cholesteatoma

• Are epidermoid tumors originating from the embryonic epidermoid rest located in the temporal bone or adjacent meningeal spaces.

• It appears as whitish globular masses lying medial to an intact tympanic membrane.

Pathogenesis Teed’s epithelial cell rest theory:• Suggested by Teed in 1936• the persistence of squamous epithelial cell

rests in the temporal bone lead to the formation of congenital cholesteatoma.

Pathogenesis Implantation theory: • Friedberg suggested, viable squamous

epithelial cells in the amniotic fluid present in the middle ears of neonates and hypothesized that this was a possible source of congenital cholesteatoma

Pathogenesis Ruedi's invagination theory:• This theory suggests that in utero infection

of tympanic membrane causes invagination of ear drum into the middle ear cavity causing congenital cholesteatoma.

Post-traumatic cholesteatoma

a/c Tertiary AcquiredMechanisms:• Epithelial entrapment in fracture line• In growth of epithelium through fracture

line• Traumatic implantation of epithelium into

middle ear

Causes of bone destruction

• Hyperaemic decalcification• Osteoclastic bone resorption due to:

o Acid phosphatase o Collagenaseo Acid proteases o Proteolytic enzymeso Leukotrienes o Cytokines

• Pressure necrosis: No role• Bacterial toxins: No role

Evaluation • History• Head and neck examination • Otologic examination • tuning fork examination-conductive hearing loss • Hearing evaluation (PTA) -conductive hearing loss • Tympanometry-Flat tympanograms • CT scan of temporal bones

Complications• Infection• Otorrhea• Bone destruction

o Ossicles, tegmen • Hearing loss• Facial nerve paresis or paralysis• Labyrinthine fistula• Intracranial complications

Management • Aural toilet• Antibiotics• Grommet insertion (to manage early retraction

pockets) • Canal wall down mastoidectomy

Aural toilet• Done only for active stage – Dry mopping with cotton swab – Suction clearance: best method – Gentle irrigation (wet mopping) Removes accumulated debris Acidic pH discourages bacterial growth

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