8 Congenital Cholesteatoma of the Middle Ear



10.1055/b-0039-169412

8 Congenital Cholesteatoma of the Middle Ear


Congenital cholesteatoma is defined as an epidermoid cyst that develops behind an intact tympanic membrane in a patient with no history of otorrhea, trauma, or previous ear surgery. Michaels studied fetal temporal bones and demonstrated the presence of an epidermoid structure between 10 and 33 weeks of gestation. This structure tends to involute spontaneously until it completely disappears. Michaels hypothesized that the persistence of this structure could act as anlage and lead to congenital cholesteatoma. The fact that the most classic location of congenital cholesteatoma, namely in the anterosuperior part of the tympanum, corresponds to the site of the fetal Michaels structure supports this theory. In our cases, however, and contrary to the few studies reported in literature (Derlacki and Clemis 1965, Friedberg 1994, Levenson et al 1986, Cohen 1987), the most common site of congenital cholesteatoma was the posterior mesotympanum. To clearly describe the location of congenital cholesteatomas, we introduced a classification designating mesotympanic localization type A. The type A is subclassified into two: anteri- or localization type A1 (▶Fig. 8.1), and posterior localization type A2 (▶Fig. 8.2). Congenital cholesteatomas localized in the attic are classified as type B (▶Fig. 8.3). If the cholesteatoma occupies both the mesotympanum and the attic, it is classified as type A/B (▶Fig. 8.4). According to our experience out of 44 cases, half of congenital cholesteatomas arise from the retromalleolar area, and premalleolar localization is uncommon (▶Table 8.1). As no existing theory can truly explain the origin of congenital cholesteatoma in the posterior location, a strong conjecture can be made that these lesions might represent a different entity from those of the anterior location that may arise from residue of transiently formed epidermis in fetal period.


Diagnosis is either occasional in the asymptomatic patient, or the patient may complain of hearing loss, or checked in the hearing examination in childhood due to erosion of the ossicular chain. On the other hand, hearing disturbance may be minimal in some cases due to sound transmission through cholesteatoma. In childhood, patients usually do not complain or even aware of hearing disturbance. Recurrent attacks of either acute or secretory otitis media caused by its presence may take the patient to the outpatient clinic, giving chance to be diagnosed. A high degree of suspicion and thorough examination are essential in detecting the presence of these lesions. Anterosuperior cholesteatoma tends to be found in earlier infancy under otoscopic examination, but diagnosis of posterosuperior cholesteatomas tends to be delayed, until screening of hearing. A high-resolution computed tomography (CT) usually reveals either a round-shaped soft tissue density, or a soft tissue filling the middle ear with disrupted ossicular chain. However, in limited cases of open-type cholesteatoma, a disrupted ossicular chain together with scanty thickening of soft tissue around the oval window may be the only finding in radiology, and differential diagnosis from congenital ossicular chain anomaly is difficult (Kim). Cholesteatoma matrix covered with small amount of debris is verified during surgery.

Fig. 8.1 Type A1 congenital cholesteatoma localized in the premalleolar mesotympanum.
Fig. 8.2 Type A2 congenital cholesteatoma localized in retromalleolar mesotympanum.

Basic strategy of surgery for congenital cholesteatoma is the same as acquired ones. In case of child, preservation of the posterior wall should be tried as much as possible. Anterosuperior cholesteatoma can be removed with retroauricular transcanal approach with preservation of the ossicular chain. The incus, then the head of the malleus should be removed if there is a risk of leaving matrix behind. In limited cases of small posterosuperior cholesteatoma, removal can be carried out through transcanal approach. However, the majority of posterosuperi- or cholesteatomas and advanced cholesteatomas require canal wall up mastoidectomy to explore the mastoid, the facial recess, and the medial wall of the attic. Even when the mastoid seems normal in radiologic examinations, open-type cholesteatoma may reach the antrum. Sufficient, but not excessive thinning of the posterior meatal wall and large posterior tympanotomy play key role in large cases. Reconstruction of the ossicular chain is carried out either in the same stage or in the second stage depending on the status of mucosa and possibility of residual. If there is any risk of residual disease, staging strategy is applied. In very limited cases of advanced cholesteatoma, application of canal wall down technique is mandatory. Since the disease can be bilateral, or might be complicated with contralateral middle ear anomaly, or deafness, it is also important to check contralateral hearing before surgery using objective hearing test such as the auditory brainstem response (ABR), when pure-tone audiometry is not possible. In cases with possible contralateral hearing loss, there is one-stage surgery with ossicular chain reconstruction.

































Table 8.1 Localization of congenital cholesteatoma of the middle ear (our experience)

Type


Location


%


Type A


Mesotympanum


52




  • A1


Premalleolar


5




  • A2


Retromalleolar


47


Type B


Attic


7


Type A/B


Mixed


41

Fig. 8.3 Type B congenital cholesteatoma localized in the attic.
Fig. 8.4 Type A/B congenital cholesteatoma presents in both the mesotympanum and the attic.


Case 8.1 (Right Ear)


See ▶Fig. 8.5, ▶Fig. 8.6, ▶Fig. 8.7, ▶Fig. 8.8, ▶Fig. 8.9, ▶Fig. 8.10, ▶Fig. 8.11, ▶Fig. 8.12, ▶Fig. 8.13.

Fig. 8.5 The axial CT demonstrates a round-shaped soft tissue anteriorly to the handle of the malleus (arrow) eroding the superior wall of the eustachian tube. The posterior half of the tympanic cavity is free of disease. C, cochlea; Ch, cholesteatoma.
Fig. 8.6 The external auditory canal is opened through retroauricular incision. A whitish mass in the anterosuperior quadrant is identified through the transparent tympanic membrane.
Fig. 8.7 The tympanic membrane is detached from the superior part of the bony annulus, and the handle of the malleus. Congenital cholesteatoma located anteriorly to the handle is started to be visualized. Absence of the matrix anterolaterally designates the cholesteatoma “open-type.”
Fig. 8.8 To control inferior pole of the matrix, the tympanic membrane is freed from the handle of the malleus. Sharp dissection is needed in this dissection. The cholesteatoma reaching the eustachian tube is seen.
Fig. 8.9 The anterior pole of the cholesteatoma is under control. Since matrix is absent in this area, the bony annulus is left untouched.
Fig. 8.10 With a tympanic sinus hook, the matrix is dissected from the anterior crus of the stapes. Care should be taken not to break the cholesteatoma matrix, and not to put an excessive force on the ossicular chain. I, incus; M, malleus.
Fig. 8.11 The cholesteatoma freed from the middle ear structures is shown.
Fig. 8.12 Suspicious areas for residual, especially near the cochleariform process, are rubbed with cottonoid to ensure complete removal of cholesteatoma.
Fig. 8.13 The cholesteatoma is eradicated from the middle ear. The bony bulge courses toward the malleus corresponds to the semicanal for tensor tympani muscle. I, incus; TT, tensor tympani.


Case 8.2 (Right Ear)


See ▶Fig. 8.14, ▶Fig. 8.15, ▶Fig. 8.16, ▶Fig. 8.17, ▶Fig. 8.18, ▶Fig. 8.19, ▶Fig. 8.20, ▶Fig. 8.21, ▶Fig. 8.22, ▶Fig. 8.23, ▶Fig. 8.24, ▶Fig. 8.25, ▶Fig. 8.26, ▶Fig. 8.27, ▶Fig. 8.28, ▶Fig. 8.29.

Fig. 8.14 A case of congenital cholesteatoma is shown. A round-shaped mass located to the handle of the malleus (arrow) corresponds to cholesteatoma. C, cochlea; Ch, cholesteatoma.
Fig. 8.15 A case of congenital cholesteatoma is shown. To verify presence of cholesteatoma, myringoplasty was conducted elsewhere. Crusting is seen in the anterosuperior quadrant, and whitish mass is seen with transparency beneath the area. Bony protrusion impedes access to the tympanic membrane to some extent.
Fig. 8.16 Calibration of the bony meatus is carried out. An aluminum sheeting is used to protect the tympanomeatal flap.
Fig. 8.17 The tympanomeatal flap is elevated and the tympanic cavity is opened. A whitish mass is seen anteriorly to the malleus (yellow arrow). No pathology is found in the posterior half of the cavity. IS, incudostapedial joint; M, malleus; RWN, round window niche; ST, tendon of stapedial muscle.
Fig. 8.18 The tympanic membrane is detached from the handle of the malleus. Open-type cholesteatoma is seen. Matrix covers only the superior part of it. Some part of tympanic membrane corresponding to previous myringotomy is adherent to the cholesteatoma and is left in place (arrow).
Fig. 8.19 Dissection is carried out from superior pole, and advanced inferiorly along the handle of the malleus.
Fig. 8.20 The majority of the cholesteatoma matrix is removed except a small remnant (arrow) on the anterior face of the handle of the malleus. ET, eustachian tube; I, incus.
Fig. 8.21 The matrix adherent to the handle of the malleus is removed.
Fig. 8.22 The final piece of matrix located anteriorly to the lateral process of the malleus is removed. Eradication of cholesteatoma from the middle ear is accomplished without disrupting the chain. I, incus; M, malleus; RWM, round window membrane; S, stapes.
Fig. 8.23 The carotid artery (arrow) turning anteromedially toward the petrous apex is identified in the inferior wall of the eustachian tube. TT, tensor tympani.
Fig. 8.24 The tympanic cavity is packed with pieces of Gelfoam.
Fig. 8.25 The tip of the handle of the malleus (arrow) is passed through a cut made in the fascia.
Fig. 8.26 The handle of the malleus is exteriorized. The arrangement reduces the risk of postoperative lateralization of the tympanic membrane. The fascia should be pushed under the bony annulus anteriorly and inferiorly.
Fig. 8.27 A plastic cut is made in the fascia for adequate contact of the skin to the enlarged meatus.
Fig. 8.28 Reconstruction of the tympanic membrane is completed.
Fig. 8.29 The postoperative otoscopy shows a well-epithelized tympanic membrane.


Case 8.3 (Right Ear)


See ▶Fig. 8.30, ▶Fig. 8.31, ▶Fig. 8.32, ▶Fig. 8.33, ▶Fig. 8.34, ▶Fig. 8.35, ▶Fig. 8.36, ▶Fig. 8.37, ▶Fig. 8.38, ▶Fig. 8.39, ▶Fig. 8.40, ▶Fig. 8.41, ▶Fig. 8.42, ▶Fig. 8.43, ▶Fig. 8.44, ▶Fig. 8.45, ▶Fig. 8.46, ▶Fig. 8.47, ▶Fig. 8.48, ▶Fig. 8.49, ▶Fig. 8.50, ▶Fig. 8.51, ▶Fig. 8.52, ▶Fig. 8.53, ▶Fig. 8.54, ▶Fig. 8.55, ▶Fig. 8.56, ▶Fig. 8.57, ▶Fig. 8.58, ▶Fig. 8.59, ▶Fig. 8.60, ▶Fig. 8.61, ▶Fig. 8.62, ▶Fig. 8.63, ▶Fig. 8.64, ▶Fig. 8.65, ▶Fig. 8.66.

Fig. 8.30 A case of congenital cholesteatoma in an 11-year-old child. On otoscopic examination, a whitish mass is seen in the tympanic cavity with transparency. The CT examination demonstrated that cholesteatoma (arrow) is localized mainly in the tympanic cavity, with small extension toward the attic. The incus is eroded, and continuity of the ossicular chain is impaired. C, cochlea; CA, carotid artery; Ch, cholesteatoma; EAC, external auditory canal; IAC, internal auditory canal; M, malleus; V, vestibule.
Fig. 8.31 Retroauricular incision is conducted, and the tympanic membrane is exposed by elevating a vascular strip. A whitish mass corresponding to the congenital cholesteatoma is seen with transparency in the anterosuperior quadrant of the intact tympanic membrane.
Fig. 8.32 The tympanic cavity is entered by elevating the tympanomeatal flap. Closed-type congenital cholesteatoma (Ch) is seen under the handle of the malleus (arrow).
Fig. 8.33 With a sharp knife, the periosteum covering the handle is incised. In cases with intact ossicular chain, care should be taken in this procedure, especially near the tip of the handle. Otherwise, luxation of either the incudomalleal or the incudostapedial joint may occur.
Fig. 8.34 The tympanic membrane is detached from the handle, except from its tip. The tympanic membrane is connected to the tip tightly and may require sharp dissection. The cholesteatoma extends both anteriorly and posteriorly to the handle (arrow) and extends beyond the bony annulus.
Fig. 8.35 The tympanic membrane is tightly connected to the tip of the handle and requires sharp dissection in many cases.
Fig. 8.36 The tympanic membrane is completely detached from the handle, and the cholesteatoma in the tympanic cavity is visualized.
Fig. 8.37 After verification of the discontinuity of the ossicular chain, management of the ossicular chain is started from removal of the malleus. The handle is cut just inferiorly to the lateral process with scissors.
Fig. 8.38 The head of the malleus is removed from the tympanic cavity after cutting the tendon of the tensor tympani muscle.
Fig. 8.39 Drilling of the mastoid is started from superior, to identify the middle fossa plate.
Fig. 8.40 Posteriorly, drilling is conducted to identify the sigmoid sinus.
Fig. 8.41 Together with the posterior wall of the bony meatus, these structures form triangle of attack.
Fig. 8.42 The drilling is advanced medially, with a large cutting burr, with a wide opening but without making bony overhang at the edge. Drilling in this way makes the cavity saucerized in shape and gives surgeon a good access and good visibility.
Fig. 8.43 Superiorly, the middle fossa plate is seen. The instrument is inserted toward the antrum. Note the different appearance of the middle fossa plate from surrounding bones. MF, middle fossa.
Fig. 8.44 The final bony plate covering the antrum is removed with a large cutting burr.
Fig. 8.45 The antrum is opened. The eminence of the lateral semicircular canal is indicated by the tip of the instrument.
Fig. 8.46 The antrum is opened with a cutting burr. If the ossicular chain is intact, great care should be taken not to drill over the incus. In such cases, it is better to visualize the ossicular chain as soon as possible by opening the sinodural angle, and by shifting the visual axis more posteriorly.
Fig. 8.47 The superior end of the cholesteatoma is visualized. The cholesteatoma occupies the space under the ossicular chain as seen in the preoperative CT.
Fig. 8.48 Using a raspatory, the incus is disarticulated, and taken out.
Fig. 8.49 The removed incus with malformation of the long process is shown.
Fig. 8.50 Cholesteatoma is dissected from the tympanic segment of the facial nerve (arrow) with a combined approach using cottonoid.
Fig. 8.51 The posterior bony wall is thinned with a large cutting burr.
Fig. 8.52 Opening of the fossa incudis (arrow) is started, and the matrix occupying the area is removed with a combined approach. The dotted line indicates the area to be drilled.
Fig. 8.53 The facial recess lateral to the mastoid segment of the facial nerve is opened with the largest possible cutting burr. The drill should be moved along the facial nerve.
Fig. 8.54 Posterior tympanotomy is in progress using a small diamond burr. The chordal crest is seen (arrow). With appropriate maneuver, the area may be drilled with a small cutting. However, meticulous care should be taken in such a case to avoid damaging the facial nerve running just medial to the hole; small cutting burrs easily slip into the cells and may cause serious injury (see Chapter 4).
Fig. 8.55 Cholesteatoma covering the stapes and the promontory is removed with a combined approach, using a small dissector inserted from the external auditory canal, and a suction tube from the posterior tympanotomy.
Fig. 8.56 The matrix is detached from the promontory. The lateral edge of the round window niche is seen (white arrow). The facial nerve is seen through thin bone as the whitish bundle forming medial border of the posterior tympanotomy (black arrow).
Fig. 8.57 The matrix under the facial nerve (arrow) is dissected with the microraspatory inserted from the external auditory canal.
Fig. 8.58 The matrix is detached from the promontory.
Fig. 8.59 The final part of cholesteatoma is removed from the meatus.
Fig. 8.60 The majority of the cholesteatoma matrix is removed from the middle ear.
Fig. 8.61 Since a small amount of matrix remains on the cochleariform process, the process is removed with a curette.
Fig. 8.62 The area of the stapes is explored from the meatus. To control this area, the patient’s bed should be turned toward the surgeon. Anomaly is also identified in the stapes. As seen, the majority of the superstructure is missing, except for a hypoplastic posterior crus (arrow).
Fig. 8.63 The footplate (FP) and the exposed facial nerve (FN) just superolateral to the footplate are seen from the meatus.
Fig. 8.64 A piece of Silastic sheet designed to cover the medial wall from the eustachian tube to the antrum is introduced into the tympanic cavity through a posterior tympanotomy.
Fig. 8.65 After packing the tympanic cavity with small pieces of Gelfoam placed over the Silastic sheet, a piece of temporalis fascia is grafted underlay.
Fig. 8.66 The tympanomeatal flap is replaced over the fascia. The anterior part of the meatus is packed with pieces of Gelfoam. Packing of the external auditory canal is completed through the meatus after replacing the vascular strip over the posterior wall.

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May 12, 2020 | Posted by in OTOLARYNGOLOGY | Comments Off on 8 Congenital Cholesteatoma of the Middle Ear
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