Cholesteatoma is an abnormal accumulation of keratin-producing squamous epithelium in the middle ear, the epitympanum, the mastoid, or the petrous apex. Clinical presentation of cholesteatoma in children varies with the pathogenesis and the etiology of this entity (ie, whether it is congenital or acquired). Cholesteatoma may produce a broad range of disabling or even life-threatening complications in the temporal bone or the surrounding structures. The management of pediatric cholesteatoma is complicated due to developmental issues unique to the age group and the long-term follow-up implications of surgical changes to the ear.
There are two categories of cholesteatoma - congenital and acquired.
Congenital cholesteatoma is defined as cholesteatoma in the middle ear with an intact tympanic membrane. Clinical criteria for the diagnosis include a white mass behind a normal tympanic membrane, normal pars flaccida and pars tensa, no prior history of otorrhea or perforation, and no prior otologic surgery. Prior bouts of otitis media are not grounds for exclusion as a congenital disease.1 The origin of congenital cholesteatoma is most likely a squamous cell rest in the anterior mesotympanum. The presence of an "island of skin" medial to the tympanic membrane, with its heightened mitotic activity, predisposes to the development of cholesteatoma, without antecedent pathology in the eardrum.2
Congenital cholesteatoma is usually located in the anterosuperior quadrant of the middle ear. These are usually encapsulated lesions that can be completely excised without ossicular damage.
However, these lesions may also extend superiorly and posteriorly and may involve the ossicular chain and semicircular canals. Removal thus requires more extensive surgery. When well encapsulated, congenital cholesteatomas can be removed safely with a low risk of recurrence. If unencapsulated, mese lesions assume a more aggressive behavior. An example of the latter is an extensive acquired cholesteatoma with a significant risk of residual disease.
Three mechanisms have been implicated in acquired cholesteatoma: immigration and invasion, implantation and invasion, and metaplasia.
The immigration and invasion theory is assodated with eustachian tube dysfunction. Two forms of cholesteatomas can develop. The first is primary acquired cholesteatoma, in which eustachian tube dysfunction leads to a retraction pocket, followed by accumulation of debris, and, ultimately, the formation of a cholesteatoma. The second form is secondary acquired cholesteatoma in which squamous epithelium migrates through a perforation of the tympanic membrane into the middle ear.3
Implantation of squamous epithelium into the middle ear may occur after trauma or surgery, as a variant of the second type. These iatrogenic cholesteatomas are due to trapping of squamous epithelium during tympanoplasty or ventilation tube insertion. Usually, iatrogenic cholesteatomas manifest as small "pearls" that can be exteriorized in the office.
The third or metaplasia theory maintains that, in the presence of chronic infections, the normal cuboidal epithelium transforms into a keratinized squamous epithelium that leads to cholesteatoma development.
DETECTION AND CUNICAL EVALUATION
Few symptoms are associated with congenital cholesteatoma. Usually, the affected child is asymptomatic except for a conductive hearing loss. There is no drainage or pain. Otoscopy reveals a white, retrotympanic mass, usually limited to the anterior half of the tympanic membrane.
The differential diagnosis includes tympanosclerosis. The use of a pneumatic speculum and a microscope is helpful to make the distinction. Tympanosclerosis is part of the tympanic membrane and moves with it, whereas the translucent drum moves independently from the white, retrotympanic cholesteatoma.
High-resolution computed tomography can confirm the extension of a congenital cholesteatoma. Computed tomography can also assess the extent of the disease in relation to the ossicles, the epitympanic space, and the mastoid.
Children with acquired cholesteatoma usually suffer persistent, foul-smelling otorrhea and hearing loss. Otoscopy characteristically shows an attic defect or a marginal perforation of the tympanic membrane with an accumulation of drainage and keratin debris. In mese cases, gentle and quiet cleaning is performed under the microscope to clean the external auditory canal.
Pneumatic otoscopy is an important part of the office evaluation of the child with cholesteatoma. Positive results of a fistula test raise the possibility of an erosion of the semicircular canals or the cochlea with its impending higher risk of sensorineural hearing loss. Positive results of a fistula test, facial nerve symptoms (palsy or spasm), dysequilibrium, significant nerve loss, and headaches are all indications for a preoperative computed tomography scan in these patients. The clinician must keep in mind that the cholesteatoma itself is capable of transmitting sound to the stapes footplate despite extensive ossicular erosion. Audiometry reveals a broad range of findings. Conductive hearing loss is the most common problem. Sensorineural hearing loss is a feared complication.
Historically, irrigation techniques, powder applications, and office local care had been described to exteriorize and safely decompress the accumulating keratin debris. Office treatment may be a valid management strategy for patients in whom anesthesia poses an unacceptable risk. However, such management is not recommended in children.
The two principles of cholesteatoma management are exteriorizing the trapped epithelium and removing the keratinizing squamous epithelium from the mastoid and the middle ear. These goals can be achieved using a variety of surgical approaches, depending on the severity of the disease and the amount of bony destruction. These procedures are classified as canal wall down (CWD), canal wall up (CWU), and transcanal procedures. Other procedures, including mastoid obliteration operations and intact bridge technique, are not discussed in this article.
CWD procedures are designed for exteriorization of the disease. Tympanoplasty with CWD mastoidectomy involves removal of the disease from the middle ear with tympanic membrane grafting and ossiculoplasty.
CWU procedures are based on a completely different philosophy: (1) the disease has to be removed in its entirety; (2) it is not enough to just exteriorize the disease; (3) the anatomy of the ear is respected; and (4) the posterior canal wall is left in place. The surgeon works anterior and posterior to the canal wall and the middle ear is accessed through the facial recess approach. Congenital cholesteatoma limited to the anterior mesotympanum is accessed this way. For limited disease in the attic, a transcanal atticotomy may be all that is needed to remove the cholesteatoma and to graft the tympanic membrane.
Cholesteatoma surgery has two objectives: to obtain a dry, safe ear and to maintain useful hearing. Depending on the location, the extent of the disease, and the experience and philosophy of the surgeon, a CWD or a CWU procedure could be used. We typically use the CWD procedure in 25% of our cases of cholesteatoma. We approach every case with an attempt to preserve the posterior canal wall, unless there is a specific reason for a CWD procedure (ie, disease destroying the posterior canal wall, a small mastoid, certain fistulas, or an only-hearing ear).
Cholesteatomas in children and in adults have distinct differences. Preoperatively, there is a lower rate of pediatric complications (eg, labyrmthine fistula, facial nerve paralysis, and sensorineural hearing loss). These occur in approximately 5% of children versus 13% of adults, and the difference is related to duration of the disease. However, the rates of recurrent and residual disease are higher for children.4
There are three reasons for the differences between pediatric and adult cholesteatomas: the mastoid pneumatization is more extensive in children with congenital cholesteatoma; the presence of a functional eustachian tube obstruction; and children represent a more difficult situation for adequate postoperative examination and follow-up. The concern with extensive pneumatization is that a CWD procedure would yield a large draining cavity for postoperative care and potential cavity infections. Eustachian tube dysfunction may predispose children for episodes of otitis media as well as retraction of the tympanic membrane, and postoperative cavity management, as with any office instrumentation, may be more difficult in children because of a lack of cooperation.
Most authors therapeutically approach cholesteatomas in children and adults in a similar fashion, keeping in mind the need for long-term follow-up. However, experts differ in emphasis. Sheehy reports a higher percentage of staging in children.5 Glasscock et al.6 try to preserve the normal anatomy of the ear canal, especially in children. Austin,7 a proponent of single-stage surgery, makes a point of attempting to preserve die canal wall if the mastoid is extensively pneumatized. On the other hand, proponents of CWD surgery see the higher recidivism rate in children as a strong argument for CWD surgery.
Adequate follow-up is imperative for successful management of cholesteatoma in children. The rate of cholesteatoma recidivism is proportional to the duration of follow-up. Cholesteatoma is a lifelong disease that can be either active or inactive. After healing, a yearly follow-up (or an otomicroscopic examination is necessary. Other ways of ensuring adequate follow-up include high-resolution computed tomography scan and, in the near future, perhaps endoscopy.8
Childhood cholesteatoma is an aggressive disease that demonstrates higher rates of recidivism than its adult counterpart. The priorities in ideal management include total removal, followed by hearing restoration, followed by preserving the ear anatomy. Especially in children, one must endeavor to preserve ear anatomy if it does not jeopardize total removal of cholesteatoma. Absolute indications for CWD surgery include an only-hearing ear, a severely destroyed posterior canal wall, an extremely contracted mastoid, and matrix overlying a semicircular canal fistula. Reasons for staging childhood cholesteatoma include suspected residual disease, uncertainty about total removal of cholesteatoma, severe mucosal disease, and CWU procedures in which the cholesteatoma has diffusely invaded the bone.
Adequate long-term follow-up is imperative. Patients and their families should be reminded frequently of the importance of close follow-up because recidivism is frequent. Successful management of cholesteatoma in children does not involve a rigid, "one-way" approach. The surgeon must be flexible and capable of employing the most appropriate procedure for the patient.
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2. Chen JM, Schloss MD, Manoukian JJ, et al. Congenital cholesteatoma of the middle ear in children. J Otolaryngol. 1989,18:4448.
3. Edelstein DR, Pansier SC, Han JC. Acquired cholesteatoma in the pediatric age group. Otolaryngol Clin North Am. 1989;22:955-966.
4. Sanna M, Zini C, Scandellari R, et al. Residual and recurrent cholesteatoma in closed tympanoplasty. Am ] Oto/. 1984;5:277-282.
5. Sheehy JL. Cholesteatoma surgery in children. Am J Otol. 1985;6:170-172.
6. Glasscock ME, Dickins JRE, Wiet R. Cholesteatoma in children. Laryngoscope. 1981;91:1743-1753.
7. Austin DR Single-stage surgery of cholesteatoma: an actuarial analysis. Am HJ Otol. 1989;10:419-425.
8. Arriaga MA. Cholesteatoma in children. Otolaryngol Clin North Am. 1994;27:573-591.