What Causes Congenital Cholesteatomas?
A 3-year-old female came to clinic with a report from the local preschool that she had failed her screening hearing test in her right ear.
Mother had not noted any problems hearing and said that she had 2 ear infections previously with the last one being more than 1 year ago.
The patient was otherwise well except for an upper respiratory infection about 1 month ago.
The family history was negative for any hearing problems and kidney problems.
The review of systems was negative.
The pertinent physical exam showed a happy, interactive female with no obvious gross hearing deficits during examination.
Growth parameters were 75-90%. HEENT showed a small amount of fluid behind the tympanic membrane with no erythema and normal mobility bilaterally.
The posterior 1/2 of the right tympanic membrane was obscured by cerumen.
The physician diagnosed bilateral middle ear effusion. He ordered an audiogram to be done in 2 weeks to allow time for the effusion to clear.
He also recommended over-the-counter cerumen drops to aid visualization at her follow-up appointment in 2 weeks.
Two weeks later, the effusions had cleared but he thought that there was a possible mass behind the right tympanic membrane posteriorly.
The audiogram also showed a persistent conductive hearing loss on the right.
The patient was referred to an otolaryngologist who also agreed that there was possibly a mass behind the tympanic membrane.
The radiologic evaluation by computed tomography of the head revealed a 2×3 cm mass inferior to the ossicles without erosion into the skull bones, clinically consistent with a diagnosis of a congenital cholesteatoma.
The patient’s clinical course had her taken to the operating room for removal of the cholesteatoma. Unfortunately, it had eroded into the incus and head of the malleus but the other ossicles were salvaged.
Ossicular reconstruction was planned in the future. A 2-week post-operative audiogram showed mild-moderate conductive hearing loss at some frequencies but improvement to normal at higher frequencies.
A hearing aid was also prescribed to increase amplification.
Figure 65 – Axial computed tomography images obtained
without contrast of the right and left temporal bones at the same
level demonstrate a 2 mm x 3 mm soft tissue lesion within the right
middle ear cavity, inferior to the ossicles. The ossicular chain was
intact. The lesion was felt to be compatible in appearance with a
Cholesteatomas are an epithelial-lined sac that contains squamous debris that progressively expands, potentially causing morbidity and even mortality.
They most often are acquired but can be congenital.
Morbidity includes secondary infection of the lesion and/or middle ear structures, destruction of the ossicles with potentially permanent hearing loss, destruction of the skull bones, invasion into the cranial vault with compression of the brain and surrounding structures, and infection of the brain including abscess.
Surgery usually is curative but recurrences of cholesteatomas do occur.
One retrospective case review of 51 patients (35 of which were <18 years of age) found in patients with normal hearing prior to surgery, 72% of patients had their hearing preserved within 10 decibels of their preoperative level.
However, 26% of patients had cholesteatoma recurrence and had worse hearing outcomes.
Acquired cholesteatomas usually are due to chronic middle-ear disease.
They can occur when squamous epithelium enters the middle ear in some manne: after placement of pressure-equalizing tubes or other surgery, through a spontaneous perforation of the tympanic membrane, or most commonly through a retraction pocket.
Retraction pockets are invaginations of the tympanic membrane.
Chronic eustachian tube dysfunction causes a vacuun to be created in the middle ear.
This vacuun then causes collapse in a focal area of the tympanic membrane most commonly in the posterior-superior segment of the pars tensa, or in the pars flaccida toward the attic, or in an old perforation or instrumented portion of the tympanic membrane.
As the collapsed area invaginates and expands, it closes up into itself creating a space that is lined with squamous epithelium. The squamous epithelium produces keratin debris, further increasing the size of the lesion and expanding locally into contiguous structures.
The expanding lesion can also become infected itself or cause infections in the middle ear secondary to further obstruction of the eustachian tube.
Cholesteatomas can be difficult to diagnose. Sometimes there is only an impression that something is behind the tympanic membrane or that the structures look different than other middle ear disease.
Cholesteatomas should be considered if there is a whitish mass behind the tympanic membrane, there is focal granulation tissue of the tympanic membrane, a deep retraction pocket, a draining ear that doesn’t improve after 2 weeks of treatment or new onset hearing loss in a previously operated ear.
Congenital cholesteatomas occur anywhere in the temporal bone but most often in the anterosuperior quadrant of the middle ear.
The exact origin of congenital cholesteatomas is unknown but many people believe these come from squamous inclusion cysts arising from epithelial rests in the middle ear. These are seen during fetal development, but most disappear by the third trimester. The failed involution of these epithelial rests leads to the congenital cholesteatoma.
Other theories include infection and microperforation of the tympanic membrane leading to introduction of squamous epithelium into the middle ear or seeding of the middle ear with squamous cells from the amniotic fluid.
Questions for Further Discussion
1. How are the ossicles reconstructed after cholesteatoma removal?
2. How should patients with abnormal screening audiograms be evaluated and/or treated?
3. What chronic diseases have an increased risk of middle ear disease and therefore an increased risk of cholesteatomas?
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Information prescriptions for patients can be found at MedlinePlus for these topics: Ear Disorders and Ear Infections and at Pediatric Common Questions, Quick Answers for this topic: Chronic Middle Ear Infections
To view current news articles on this topic check Google News.
To view images related to this topic check Google Images.
Rudolph CD, et.al. Rudolph’s Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:1255.
Smouha EE, Javanshir J. Cholesteatoma in the Normal Hearing Ear. Layngoscope. 2007;117;854-858.
Isaacson G. Diagnosis of Pediatric Cholesteatoma. Pediatrics. 2007:120;603-608.
ACGME Competencies Highlighted by Case
1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
2. Essential and accurate information about the patients’ is gathered.
3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
4. Patient management plans are developed and carried out.
7. All medical and invasive procedures considered essential for the area of practice are competently performed.
8. Health care services aimed at preventing health problems or maintaining health are provided.
9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.
10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.
13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
19. The health professional works effectively with others as a member or leader of a health care team or other professional group.
24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
25. Quality patient care and assisting patients in dealing with system complexities is advocated.
26. Partnering with health care managers and health care providers to assess, coordinate, and improve health care and how these activities can affect system performance are known.
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital
July 21, 2008