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Origi na l A r tic le
Role of High Resolution Computed Tomography in
Cholesteatoma
Abhijeet Kumar Sinha1, Sheikh Nizamuddin Mustafa2, Ehtesham Ahmad Raushan3, Gireesh Kumar4
Assistant Professor, Department of ENT & HNS, Teerthanker Mahaveer Medical College & Research Center, Moradabad, Uttar Pradesh, India,
Associate Professor, Department of ENT & HNS, Teerthanker Mahaveer Medical College & Research Center, Moradabad, Uttar Pradesh, India,
3
Senior Resident, Department of ENT & HNS, Teerthanker Mahaveer Medical College & Research Center, Moradabad, Uttar Pradesh, India,
4
Junior Resident, Department of ENT & HNS, Teerthanker Mahaveer Medical College & Research Center, Moradabad, Uttar Pradesh, India
1
2
Abstract
Introduction: Cholesteatoma is potentially dangerous condition as it extends and causes erosion of adjacent structures leading
to various serious complications. High resolution computed tomography (HRCT) temporal bone very clearly depicts the anatomy
of various small important structures in middle and inner ear cavity. Hence, it is an excellent modality and investigation of choice
in diagnosing and defining the extent of cholesteatoma. It has now become essential investigation in pre-operative planning for
surgeon. Present study, shows good correlation of various pre-operative HRCT findings with intraoperative findings.
Aims and Objective: To study the role of HRCT temporal bone in pre-operative evaluation of cholesteatoma.
Materials and Methods: Total 20 cases with clinically suspected cholesteatoma were selected for this study. All the patients
were from Teerthanker Mahaveer Medical College and Research Center, Moradabad. The important intra-operative surgical
findings were correlated with pre-operative HRCT findings. The results were analyzed, studied and compared with similar
studies of the past.
Results: Present study, shows good correlation between the pre-operative findings of cholesteatoma by HRCT temporal bone
and intraoperative surgical findings.
Conclusion: HRCT enables the pre-operative delineation of the cholesteatoma and the recognition of its manifestations and
complications. HRCT is found to be valuable in the diagnosis and in guiding the surgical management of cholesteatoma.
Keywords: Cholesteatoma, High resolution computed tomography, Pre-operative evaluation, Temporal bone
INTRODUCTION
squamous epithelium, from the external acoustic meatus
to the middle ear and mastoid cavity.
Middle ear cholesteatoma, which is more often acquired
than congenital has been recognized radiologically and
clinically for many years.
Acquired cholesteatoma is the main complication of
chronic otitis resulting from the in growth of keratinizing
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In computed tomography (CT) scan, hallmark of
cholesteatoma is soft tissue like opacity in middle ear cavity
and the mastoid antrum associated with smooth bony
erosion of ossicles and the adjacent structures.
Appearance of soft tissue doesn’t differ whether it is a
cholesteatoma or granulation tissue, but the association
of bone erosion is highly suggestive of cholesteatoma.
CT scan helps to understand the complex relationships of
anatomic structures. It displays internal bony architecture
of the skull base, evaluates the soft tissue pathology
associated with the disease process that helps in deciding
Corresponding Author:
Dr. Abhijeet Kumar Sinha, Palm Green Apartment, Moradabad, Uttar Pradesh, India. Phone: +91-9536861136,
E-mail: [email protected]
International Journal of Scientific Study | November 2014 | Vol 2 | Issue 8
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Sinha, et al.: Role of High Resolution Computed Tomography in Cholesteatoma
the approach to surgery and also the expected preoperative, intraoperative and post-operative complication.
Cholesteatoma of significant importance to the
otolaryngologist as it poses many challenges. Firstly, the
otologist should make a correct and an early diagnosis.
Secondly, the otologist should provide a disease free ear
that will remain safe throughout the life and can be easily
followed up.
Thirdly, to achieve, a serviceable hearing level. Fourthly, the
otologist should educate the patient and the family as to
the nature of the disease, the need for long-term followup, and the possibility of further radiographic studies,
reconstructive surgery and aural rehabilitation.
As such the cholesteatoma itself is still a most intriguing
pathological entity, since the days of Johannes Mueller,
who coined the term “cholesteatoma” in 1828, its multiple
presentation and encroachments presents with a variety of
diagnostic and therapeutic challenges.
A cholesteatoma is a sac of stratified squamous epithelium
filled with accumulation of exfoliated keratin debris that is
trapped and grown within the middle ear cleft with tendency
to erode the covering bone, in other words it can also be
called as “skin in wrong place” 98% of all cholesteatoma is
acquired arising either from pars flaccid or from pars tensa.
Acquired cholesteatoma can be classified into two
categories. The most common form is primary acquired
cholesteatoma, which arises from a skin lined retraction
pocket, within which retained keratin debris accumulates.
This is also known as attic retraction cholesteatoma and is
usually confined to the region of pars flaccida.
invasion, ultimately, reaches barriers that cause the invading
edges to meet and create a cyst or sac like structure.
This theory is known as epithelial invasion theory and is
supported by temporal bone studies of Palva et al.5
Studies by Sadé6 tend to indicate that middle ear mucosa
has the potential to transform into keratinizing squamous
epithelium.
Most common presenting symptoms of primary acquired
cholesteatoma are: Foul smelling scanty otorrhoea, hearing
loss, otalgia, tinnitus and vertigo. Most common finding
on examination of ears are, a retraction pocket either in
the ear-drum in 70%, followed by a tympanic membrane
perforation in one third and very few (8%) with a white
mass behind the tympanic membrane i.e., congenital
cholesteatoma.
Buckingham and Valvassori7 consider that there are two
criteria that distinguish a cholesteatoma of the middle ear
cleft, which has congenital rather than acquired origin.
These are:
a) An intact ear drum with no evidence of a perforation
b) An intact spur with erosion of the attic walls higher up
and not involving the site of attachment of the eardrum,
giving a scooped out appearance of outer attic wall.
Radiological history of cholesteatoma dates back to
1905, when Schuller described the first view to visualize
pathologic lesions in the area frequently involved in chronic
ear disease, namely, “attic-aditus ad antrum” or the “key
area.” This involves lateral skull view with an elevation of
the beam to 30° and gives a good exposure of the antrum
and part of the attic.
The pathogenesis of attic retraction cholesteatoma is the
subject of much research and debate. There are four basic
theories of development.
According to McMillan,8 the normal sized antrum is 6 mm
wide by 10 mm high in a sclerosed mastoid. Any increase
in size of the antrum is considered to be due to erosion
of the bone by growing cholesteatoma.
In invagination theory, Whittmack proposed that attic block
caused by persistence of hyperplastic embryonic type of
mucoperiosteum in the epitympanum results in negative
pressure in the attic which causes retraction of Shrapnel’s
membrane into the attic, where keratin debris collects and
cholesteatoma develops.
The tomographic diagnosis and evaluation of the extent of
cholesteatoma is based on the detection of bony erosion
and soft tissue changes in the middle ear and mastoid.
Of the two findings, only the first is reliable, since the
radiographic density of a cholesteatoma is same as that of
granulation tissue and other soft tissue masses (Table 1).
Ruedi, Nager and Lange1-3 in their basal cell hyperplasia
theory state that, extensions from the basal layer of the
epidermis can become invasive as a result of infection.
Table 1: Evidence of cholesteatoma
Habermann4 proposed that following perforation of
Shrapnel’s membrane, epithelium grows into epitympanum,
much like a secondary acquired cholesteatoma. This
Soft tissue density mass alone
Soft tissue density mass+bony erosion
Total
165
Evidence of cholesteatoma
Number
of cases
Percentage
4
16
20
20
80
100
International Journal of Scientific Study | November 2014 | Vol 2 | Issue 8
Sinha, et al.: Role of High Resolution Computed Tomography in Cholesteatoma
However, in high resolution computed tomography
(HRCT), the granulation tissue has higher CT attenuation
values than cholesteatoma and often can be differentiated
from the cholesteatoma.
The subject of greatest debate among surgeons relates
to the choice of surgical approach. Sheehy, Jansen and
Glasscock9-11 have advocated canal-wall-up mastoidectomy,
whereas canal-wall-down mastoidectomy has gained
acceptance by Jahnke and Palve et al.12,5
CT Findings
CT diagnosed erosion of the horizontal segment of the
facial canal accurately in 2 cases. There was a false positive
interpretation in two cases, and it failed to identify the
erosion (sensitivity 60% and specificity 90%). It was 100%
sensitivity and 95% specific for the diagnosis of erosion
of lateral semicercular canal with only one false positive
interpretation. CT diagnosed mastoid cortex erosion
accurately in one case (sensitivity 100% and specificity
94%). It was 100% sensitive and specific for sinus plate
erosion (Figure 1) (Tables 2 and 3).
MATERIALS AND METHODS
This study consisted of 20 cases of chronic suppurative
otitis media of unsafe type requiring the mastoid
exploration, admitted in the Otolaryngology Department
of the Teerthanker Mahaveer Medical College and Research
Center, Moradabad.
A clinical proforma filled up for each patient incorporating
details regarding particulars of the patient, history,
clinical examination and investigations. All patients’ ears
were examined under microscope during outpatient
otology special clinic and before surgery under operating
microscope. Hearing status was assessed by pure tone
audiometric examination according to the age and
compliance of the patient.
Radiological investigation consisted of both conventional
plain radiography and CT. In CT, high-resolution serial
2 mm thick sections were obtained in both axial and coronal
planes. Axial images were obtained parallel to the orbit
meatal plane. Coronal sections were done in scanning angle
that is parallel to vertical ramus of the mandible.
Signs that indicate cholesteatoma in the attic:
a) Destruction of the scutum
b) Bone destruction in the lateral attic wall
c) Destruction of the ossicles
d) Erosion of the medial attic wall.
All patients underwent the mastoid exploration, and the type
of surgery was determined by the otological diagnosis and
intra-operative findings. The type and extent of disease was
studied during surgery. All patients were followed up in ENT
outpatient department after 6 weeks and 12 weeks of surgical
exploration to determine the state of the mastoid cavity.
100
90
80
70
60
50
40
30
20
10
0
Ossicular
Destruction
Facial Canal
Lateral
Mastoid Cortex
Erosion
Semicircular
Erosion
Canal Erosion
Sensitivity
A total of 20 patients with chronic suppurative otitis media
and cholesteatoma requiring the mastoid exploration were
studied in ENT Department of Teerthanker Mahaveer
Medical College, Moradabad within the period of
24 months.
Specificity
Figure 1: Sensitivity and specificity of HRCT
Table 2: Complication of cholesteatoma
CT findings
Number of cases
Percentage
15
4
1
1
1
0
75
20
5
5
5
0
Ossicular destruction
Facial canal erosion
Lateral semicircular canal erosion
Mastoid cortex erosion
Sinus plate erosion
Dural plate erosion
CT: Computed tomography
Table 3: Correlation of CT scan and operative
findings
Findings
Observations
Sinus Plate
Erosion
Ossicular destruction
Facial canal erosion
Lateral semicircular
canal erosion
Mastoid cortex erosion
Sinus plate erosion
CT scan Surgery Sensitivity Specificity
15
4
1
18
2
1
84
60
100
100
90
94
1
1
1
1
100
100
94
100
CT: Computed tomography
International Journal of Scientific Study | November 2014 | Vol 2 | Issue 8
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Sinha, et al.: Role of High Resolution Computed Tomography in Cholesteatoma
DISCUSSION
This study was conducted to correlate the computed
tomographic findings with that of surgical findings in them.
This study included 20 patients with the clinical diagnosis
of chronic suppurative otitis media and cholesteatoma.
The commonest age group in our patients was 10-20 years
(35%). There were 11 boys and 9 girls. Left ear (70%) was
more commonly involved than right ear (15%) and 3 (15%)
patients had bilateral ear disease (Figures 2 and 3).
Commonest complaints were otorrhoea (100%) followed
by hearing loss (85%), tinnitus (20%) and vertigo (5%). In
addition, 3 (15%) of our patients presented with post-aural
abscess and pain.
The average duration of complaints was 6.9 years.
Microscopic examination of the ear preoperatively revealed
a variety of abnormalities. The presence of retraction
pocket, mainly in the poster superior region was the
commonest finding (60%). 30% of the patients had an
attic retraction. 40% of the patients had perforations in the
tympanic membrane. Similar to this study cholesteatoma
was visualized in 95% of the cases and commonest sites
of cholesteatoma were in posterosuperior and attic region.
2 (10%) patients had sagging posterior canal wall. One
patient had an operated cavity and other one case, a polyp
filling external auditory canal.
All patients had conductive hearing loss except one patient,
who had a mixed hearing loss with 30 dB AB gap. The
common range (44%) of hearing loss was of moderate
degree 48 with 30-40 dB AB gap.
All patients underwent modified radical mastoidectomy
except one patient, in whom intact canal wall mastoidectomy
was done. Commonest pathology was cholesteatoma (70%).
10% had only granulations. Granulations were associated with
cholesteatoma in 10% of the cases and a polyp in 5% of the
cases. One patient had only mucosal hypertrophy (Table 4).
17 (84%) cases had an extensive disease, 9 (44%) of
them had disease involving attic, aditus and antrum and
remaining 8 (40%) of them had involvement of middle ear
in addition to these. In our study, ossicular involvement
was seen in 18 (90%) cases.
The horizontal segment of the facial canal was dehiscent in
2 (10%) patients. Erosion of the lateral semicircular canal
was observed in only 1 (5%) patient. 1 (5%) patients had
destruction of the mastoid cortex and only 1 (5%) patient
had sinus plate destruction. All patients were followed up
regularly in ENT outpatient clinic after 6 and 12 weeks.
SUMMARY AND CONCLUSIONS
T h i s s t u d y “ r o l e o f H RC T i n e va l u a t i o n o f
cholesteatoma,” was conducted in 20 patients with
chronic suppurative otitis media and cholesteatoma
treated in otolaryngological services of Teerthanker
Mahaveer Medical College, Moradabad and following
conclusions were drawn:
1. Majority of the patients (35%) were more than 10 years
with male predominance (11:9) and left ear (70%) was
commonly involved
2. Commonest complaints were otorrhoea (100%) and
hearing loss (85%) and average duration of complaints
was 6.9 years
3. Posterosuperior retraction pocket of the pars tensa
(60%) was the commonest ear finding followed by
Figure 2: Cholesteatoma left ear
Table 4: Distribution of surgical findings
Pathology
Figure 3: Cholesteatoma left ear showing ossicular destruction
167
Cholesteatoma
Cholesteatoma+granulations
Polyp+cholesteatoma
Granulations
Mucosal hypertrophy
Number of patients
Percentage
14
2
1
2
1
70
10
5
10
5
International Journal of Scientific Study | November 2014 | Vol 2 | Issue 8
Sinha, et al.: Role of High Resolution Computed Tomography in Cholesteatoma
4.
5.
6.
7.
the attic retraction (30%). 40% of the patients had
perforation in the tympanic membrane
Majority (44%) of the patients had a moderate degree
of the conductive loss
96% of the patients underwent modified radical
mastoidectomy, and extensive disease was observed in
84% of the patients. Ossicular involvement was seen
in 100% of the cases
The horizontal segment of the facial canal was eroded in
10% of the patients, erosion of the lateral semicircular
canal in 5% of the patients, mastoid cortex dehiscence
in 5% and sinus plate destruction in 5% of the cases
After 6 weeks, 96% of the patients had ear discharge
and after 12 weeks, 16% of the patients continued to
discharge.
Correlation of Computed Tomographic Findings with Surgical
Findings
The high resolution computerized tomographic scan was
both sensitive and specific in diagnosing cholesteatoma,
assess the extent of the disease, identifying bony erosion
and the ossicular destruction.
1. The HRCT was 100% sensitive and 50% specific in
diagnosing cholesteatoma, but could not differentiate
cholesteatoma from granulations
2. The HRCT was highly sensitive and specific in
identifying the ossicular destruction.
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How to cite this article: Sinha AK, Mustafa SN, Raushan EA, Kumar G. Role of High Resolution Computed Tomography in
Cholesteatoma. Int J Sci Stud 2014;2(8):164-168.
Source of Support: Nil, Conflict of Interest: None declared.
International Journal of Scientific Study | November 2014 | Vol 2 | Issue 8
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