Cholesteatoma

As cholesteatoma (synonym: Perlgeschwulst, onion tumor, otitis media epitympanalis ) of the ear is called a multilayered keratinizing squamous Einwucherung of the middle ear with subsequent chronic purulent inflammation of the middle ear of mammals. Chronic middle ear inflammation in cholesteatoma is referred to as chronic suppuration of bones. The cholesteatoma is a progressive, destructive manner inflammatory lesion. The cholesteatoma shows from the pathological point of view the following characteristics: migration, increased cell proliferation, invasiveness, impaired cell differentiation, progression and tendency to recur after surgical intervention.

In a healthy ear, the keratinizing squamous epithelium of the external auditory meatus and the mucosal epithelium of the middle ear through the tympanic membrane are completely separated from each other. If this barrier removed, squamous cells can grow into the tympanic cavity. This results in a spread of keratinizing squamous epithelium in the middle ear.

Cholesteatoma may also occur outside of the ear in the skull or skull wall.

• 5.1 Further investigations, diagnoses 5.1.1 Imaging Techniques
• 5.1.2 Audiometric procedures

• 7.1 Operating procedure for Cholesteatomtherapie

History of Medicine

Joseph- Guichard You Verney reported the first a fatty mass in the temporal bone and called this " Stéatome ." Jean Cruveilhier called in 1829 the mass in the petrous descriptive tumeur perlée because of the macroscopic bead-like appearance. The today common medical term of " cholesteatoma " goes back to the German physiologist and comparative anatomist, Johannes Peter Müller, who reckoned them to the benign adipose tissue tumors.

Joseph Toynbee described in 1850 under the name molluscous tumor and later sebeaceous tumor growths in the ear, but the Toynbee as the primary Balggeschwülste ( by a bellows limited tumors composed of epidermic scales ) of the ear canal looked at her, but rather resembled a cholesteatoma. He again saw its origins in the sebaceous glands.

As part of the operations in chronic suppuration of the mastoid it was Ernst von Bergmann demanded a further acquisition of the posterior meatal wall in 1899. He named this surgical step " radical surgery of the ear ."

Pathogenesis

Physiologically, the tympanic cavity is lined with a single cubic ( isoprismatischem ) to plates epithelial layer. Penetration in this tissue system keratinizing squamous one, so it comes to a proliferation of keratinocytes of the squamous or do they develop from embryonic Mesenchymresten these begin with a change in growth behavior to multiply, creating an onion- shaped pearl from keratinizing squamous which is form the Cholesteatommatrix the destruction the surrounding tissue will result.

Here, the histologically different eardrum sections are to be considered. Small pars flaccida or Shrapnell'sche membrane consists of two layers; the external auditory canal to himself finds a stratified squamous epithelium, stratum cutaneum, while at the tympanic cavity through a single- squamous stratum mucosum trained. Between the two different cell layers just the basal lamina. Not so with the larger pars tensa, here the two cell layers and the basal lamina are also formed, but in addition can be two fiber layers of connective tissue, fibrous layer or lamina propria differ. One of these fiber layers has a radial gradient, stratum radiatum and the other is circularly arranged stratum circulare.

The different histological structure results in terms of a preferred site at a preferential occurrence as a primary cholesteatoma in the pars flaccida. Because chronic tubal ventilation disorders can lead to a retraction pocket in the pars flaccida. In such a retraction pocket it comes to Epithelabschilferungen that accumulate in the sequence in the tympanic cavity and develop over time and through altered cellular factors then cholesteatoma.

Instructions to the changed compared to the normal conditions of the eardrum Plattenepithelschicht are detectable high concentrations of growth factors, epidermal growth factor receptor ( EGFR), transforming growth factor, TGF- α, interleukin -1, IL -1 in the Cholesteatommatrix. View all The stronger growth of the keratinocytes. In addition, the plasminogen activator system, PAS and the matrix metalloproteinases system play an important role. Tissue proliferation requires mass transfer and this in turn angiogenesis. Although such a neovascularization and is also the requirement for a physiological growth in the body, but it plays an important role in wound healing by tissue damage. The squamous epithelium of the Cholesteatommatix can not stimulate neovascularization, but the surrounding perimatrix and their cell components are of mesenchymal origin and is capable, as such, to the induction of angiogenesis.

From the Cholestatommatrix so the Cholesteatomperimatrix distinction must be made, this arises from the subepithelial connective tissue. This product allows the cholesteatoma from histopathological point of view, constitute two essential layers.

The Cholestatommatrix is the superficially located epithelial layer with keratinizing squamous cell detritus and. It resembles the Trommelfellepithel and the Gehörgangsepithel, but without the appendages.

On the other hand, the perimatrix represents the underlying connective tissue, it is activated and responsible for igniting the mass transfer of the epithelium. The perimatrix, so the anti -activated connective tissue, consists histomorphologically of the following cells: fibroblasts, macrophages, lymphocytes, mast cells, granulocytes, endothelial cells, and activated in the bone osteoclasts.

Depending on its thickness and extent of inflammatory activity is different. At high inflammatory activity located between matrix and basement membrane perimatrix places interrupted sein.Diese may accompany inflammatory reaction results on the effect of various cytokines to inflammatory -induced activation and chemotaxis of osteoclasts in the cholesteatoma surrounding bone. This inflammation can spread to the bony elements of the middle ear and the inner ear, which are thereby gradually destroyed.

Presumably through the further disturbed secretion drainage and a bacterial superinfection - often with Pseudomonas aeruginosa - leads the ingrown epithelium to an increase in the inflammatory process.

The cholesteatoma is in the cross-section of snow-white, onion- like superimposed dead epithelial layers. Envelops are keratinizing epithelium of these (matrix) that produces the epithelial layers, and a (mostly ) inflamed mucous membrane layer ( perimatrix ), which is responsible for bone destruction. In addition, inflammatory and regressive changes.

Assuming an inflammatory process of the form you can circle of otitis media chronica, ie a chronic otitis divided into:

• Chronic Schleimhauteiterung, and chronic otitis mesotympanale; what does it mostly comes through the Eustachian tube to an inflammation in the middle ear. Characteristic of this disease is the central defect in the tympanic membrane. The eardrum edge, the annulus fibrosus is get anywhere.
• Chronic bone suppuration, and chronic otitis media epitympanale; here is a form of cholesteatoma. When looking with the otoscope on the eardrum can be found there, at the edge typically has a defect, also you can see whitish granulations or red pseudo polyps in the defect.

A total of four theories for the acquired cholesteatoma, ie the primary and secondary cholesteatoma, essentially offered to its development:

• The Immigration theory; a tympanic membrane defect can be marginal keratinocytes of the multilayered squamous epithelium, stratum corneum grow into the tympanic cavity and thereby induces an inflammatory response. This inflammatory milieu creates a growth stimulus for the squamous epithelium.
• The metaplasia theory; expressed by cytokines occurs in the single squamous stratum mucosum the tympanic cavity to a metaplasia of the epithelium.
• The retraction or retraction pockets theory; in this theory first is the mechanical action of negative pressure or negative pressure in the middle ear cavity, due to a (chronic ) tube ventilation disorder, in the heart of the action. Result, the formation of a retraction pocket is favored and an accumulation of keratinocytes then forms the basis for the forming cholesteatoma.
• The theory of Basalzellenhypertrophie; Keratinocytes can penetrate a patchy basal lamina under certain circumstances. In the lamina propria of connective tissue or fibrous layer and thus penetrated into the subepithelial space arise due to increasing keratinization, called Einschlußzysten.

Classification

The classification of inflammatory Mittelohrcholesteatome can be made ​​up of different points of view, as primary, secondary or topographical anatomy. The most plausible form is that of classification according to the place of occurrence.

With regard to the origin or to the place where one can distinguish three forms of cholesteatoma:

Primary cholesteatoma

In primary cholesteatoma missing inflammation in prehistory.

• Retraktionscholesteatom: origin of cholesteatoma is the formation of a so-called retraction pocket in the pars flaccida ( Shrapnell'sche diaphragm ) of the eardrum in the uppermost part of the tympanic membrane, presumably by a chronic disorder of ventilation tubes. The cholesteatoma develops from the retraction pocket and spreads initially in the dome space of the middle ear ( Attik ) from; this is called cholesteatoma therefore Attikcholesteatom.
• Immigrationscholesteatom: It is produced by active epithelial ingrowth into the Shrapnell'sche membrane.

Secondary cholesteatoma

When secondary cholesteatoma can be found in the history of middle ear infections or (chronic ) Mittelohrkatarrhe.

The secondary cholesteatoma arises on the basis of an inflammatory incurred, deeply indented, ultra-thin ( = atrophic ) eardrum scar in the posterior tympanic portion ( sinus tympanic - cholesteatoma ) or by a so-called middle ear atelectasis, in which the entire eardrum changed atrophic and to the inner wall middle ear is sucked ( pars tensa - cholesteatoma ). By inflammatory changes and accumulation of whitish Cholesteatommaterial the retraction pockets impress often as tympanic membrane. Real marginal perforations after necrotizing otitis (eg scarlet fever ) as the starting point of a cholesteatoma is rare today.

Congenital cholesteatoma

The rare congenital cholesteatoma arises from Zellversprengungen during the embryonic phase, more precisely by not fully formed mesenchymal tissue back in the submucosa of the middle ear. In contrast to other congenital cholesteatoma, the cholesteatoma develops behind the eardrum is intact and (at least primarily ) without contact with the tympanic membrane.

Symptoms

• Smelly smelly ear discharge ( otorrhoea fetid )
• Progressive conductive hearing loss

If complications arise:

• Dizziness
• Facial paralysis ( Bell's palsy )
• Deafness
• Earache, headache, fever

Findings and diagnosis

The diagnosis is made by means of the ear microscopy. The typical finding is a defect in the pars tensa or pars flaccida of the tympanic membrane with proof whitish- yellow flakes or masses of cells in the lesion. Not infrequently find polyps from granulation tissue. An examination by the direct otoscopy one often sees the eardrum perforation of the tympanic membrane at the top or rear edge.

In most cases you will find the cholesteatoma on the upper rear part of the tympanic cavity, so that its detritus but then emptied through a perforation in the pars flacccida of the tympanic membrane, rarely also in the pars tensa at the edge near the fibrous ring, the annulus fibrocartilagineus in the ear canal.

Further investigations, diagnoses

Imaging methods

Furthermore, computed tomography images are produced (CT). For this purpose, the high-resolution spiral computed tomography has been established as a method of first choice. With it it is possible to bring the delicate morphological structures of the temporal bone region for the representation, a region requires the highest demands on the spatial resolution and image quality of CT images. High-resolution computed tomography (HR- CT, . Engl high resolution computed tomography ) the anatomical structures in thin film technology and the presentation in the bone window in the axial and coronal plane come to represent. The basis of a high-resolution temporal bone CT is the axial projection plane.

Before the introduction of CT special radiographs were used by Schüller and Stenvers for diagnosis. Under the X-ray after Artur Schüller (1874-1957), shortly after recording Schüller, understood as an imaging of the skull. The radiographic plate is at the side of the ear and the central ray is from the opposite side at an inclination angle of 20 ° to 30 ° from the top of the ear canal close to the ear of the plate. Thereby, the mastoid antrum with, which übereinanderprojizierende external and internal auditory canal as well as parts of the TMJ can be detected.

The X-ray after Hendrik Willem Stenvers (1889-1973), shortly after recording Stenvers, is an x-ray of the skull. Dei x-ray plate is placed obliquely sideways - at a 45 ° angle frontotemporal - in front of the orbit, the orbit and the zygomatic bone. The central beam is at an angle of 12 ° to 15 ° relative to the horizontal, the virtual right angle to the X-ray plate. This setting allows a longitudinal view of the temporal bone allow.

Cloudy; So a dark area on a radiograph, which projects to the middle ear or the mastoid antrum, are often associated with cholesteatoma. At advanced stages of a cholesteatoma can be seen in the area of the antrum radiographically as a large rounded defect ( as a dark region in the x-ray after Schüller ) furthermore often found signs of increased sclerosis of the bone in the mastoid. This is the radiological expression of the inflammatory processes induced cholesteatoma in chronic mastoiditis.

Audiometric procedures

The audiogram can provide evidence of conductive hearing.

Complications

• Destruction of the ossicles
• Inner ear damage
• Fistula with the arcade system
• Bell's palsy (facial nerve palsy )
• Spread of inflammation: meningitis, brain abscess, sepsis (blood poisoning)

Therapy

A cholesteatoma can only be removed by surgery. Concomitant systemic antibiotic therapy is performed to reduce the inflammatory process and to provide better operation conditions in the rule.

When in operation, the cholesteatoma can be completely removed, the tympanic membrane and ossicles can be restored ( tympanoplasty ).

Prolonged cholesteatoma or substantial destruction a radical cavity must be created by a radical mastoidectomy. Here, a common cavity from the ear canal, mastoid cavity and the dome space of the middle ear is made, which is visible from the outside on the extended auditory meatus and accessible for cleaning. Also in this case, often the former middle ear closed with a new eardrum and hearing are thus improves again (so-called flat drum).

The primary goal of the surgical procedure is the restoration of the destructively inflammatory process in the mastoid and the tympanic cavity. Operational objective is the complete removal of cholesteatoma. Only secondarily an improvement or preservation of hearing is sought, so that a two -stage operation about a tympanoplasty is necessary.

Surgical procedure in the Cholesteatomtherapie

Crucial for operational planning is to answer the question whether the rear wall of the meatus, mastoid antrum can be obtained or whether it must be removed as well. A distinction is made in planning the operative rehabilitation between an open and a closed approach. When spillover of cholesteatoma on the mastoid, mastoid two procedures must be described:

• The open procedure or engl. canal wall down technique ( CWDT ) or
• The closed approach of the English. intact canal wall technique ( ICWDT ) mastoidectomy.

In the open procedure, canal wall down technique ( CWDT ) or radical cavity, the posterior wall of the meatus, the lateral attic wall and gradually the cholesteatoma is removed. It forms thus a wound cavity consisting of the dome space of the middle ear ( epitympanum ), the mastoid and the auditory canal with removal of the posterior meatal wall. This wound or radical cavity formed over a behind the ear ( retroauricular ) or any holding in the ear ( enauralen ) access, through the surgical removal of lateral dome chamber wall and the posterior bony canal wall. In the case of an initially large wound cavity about turn by a muscle - periosteal tissue flap is trying to reduce this. This is conditional on the safe removal of all cholesteatoma herd.

The closed procedure, intact canal wall technique ( ICWDT ) tried the rear wall of the meatus, and thus to preserve their function or to reconstruct. To reconstruct either serve parts of the removed rear wall of the meatus or elastic cartilage of the tragus.

Follow-up

The operated patients, according to a Cholesteatomeingriff need to regularly undergo an ENT medical examination.