Cholesteatoma
Updates to Article Attributes
Cholesteatoma is histologically equivalent to an epidermoid cyst and is composed of desquamated keratinizing stratified squamous epithelium forming a mass. They usually present with conductive hearing loss.
Pathology
The mass is lined by epithelium (facing inwards) which continues to grow, thereby shedding additional cells into the mass. Their cholesterol content (which is not always present) is responsible for their name, although 'keratoma' is probably a more apt term.
Cholesteatomas of the temporal bone and middle ear can be divided into:
- congenital cholesteatoma: accounting for only 2%
-
acquired cholesteatoma: 98%
- primary (no history of chronic otomastoiditis)
- secondary ( the vast majority):
- pars flaccida
- pars tensa
- external ear canal cholesteatoma
- mural cholesteatoma
Radiographic features
MRI
Conventional non-contrast MR imaging with diffusion-weighted imaging is recommended in all patients with a suspicion of cholesteatoma. EspeciallyAn MRI should be performed especially in patients with previous surgery for cholesteatoma an MRI should be performed since recurrence or residual tumour can be detected with great accuracy. If negative, it can avoid aobviate "second look" surgery. It is important to prepare the patient for the examination (clear the external auditory canal or the postoperative cavity) to avoid a false positive diagnosis.
The standard examination is a T2 weighted-weighted series in the coronal and axial plane, followed by a non-EP-echoplanar DWI series (b-values 0, 1000). On the DWI images with b-value 1000 s/mm2, a cholesteatoma becomes apparent as a hyperintense area. The signal intensity should be higher than visible on the DWI images with b-value 0 s/mm2. On the ADC-map map, low-signal signal should be visible in the same area, confirming the presence of diffusion restriction.
CT
A CT-scan scan should be added in those cases where a cholesteatoma is detected with MRI. CT is neededrequired for preoperative planning (reconstruction of ossicles if needed) and to exclude perforation of the bony tegmen.
Pars flaccida cholesteatoma originates in Prussak's space and usually extends posteriorly.
Pars tensa cholesteatoma originates in posterior mesotympanum and tends to extend posteromedially.
Differential diagnosis
- cholesterol granuloma
- inflammation
In contrast with cholesteatoma, these show high signal on the ADC map. With these findings, recurrent cholesteatoma can be detected with 100% specificity. Cholesteatomas updown to a size of 2 mm can be detected with this technique on a 1.5T MRI machine.
Further differential diagnosis is to be made with:
- cerumen: which shows similar image characteristics to cholesteatoma but is located in the external ear
- abscess formation in the middle ear: can also show similar imaging findings but has a completely
differentdifferent clinical appearance
Practical points
Important CT features to comment on when reporting a cholesteatoma:
- erosions of the
- dehiscence of the
- the integrity of the
- epitympanum
- aditus ad antrum and mastoid antrum
- oval and round window
- the presence of cholesteatoma in the sinus tympani (which is the most hidden recess of the middle ear)
-: to avoid residual disease
-</ul><h4>Radiographic features</h4><h5>MRI</h5><p>Conventional non-contrast MR imaging with diffusion-weighted imaging is recommended in all patients with a suspicion of cholesteatoma. Especially in patients with previous surgery for cholesteatoma an MRI should be performed since recurrence or residual tumour can be detected with great accuracy. If negative it can avoid a "second look" surgery. It is important to prepare the patient for the examination (clear the external auditory canal or the postoperative cavity) to avoid false positive diagnosis.</p><p>The standard examination is a T2 weighted series in the coronal and axial plane, followed by a non-EP DWI series (b-values 0, 1000). On the DWI images with b-value 1000 s/mm<sup>2</sup>, a cholesteatoma becomes apparent as a hyperintense area. The signal intensity should be higher than visible on the DWI images with b-value 0 s/mm<sup>2</sup>. On the ADC-map low-signal should be visible in the same area, confirming the presence of diffusion restriction. </p><h5>CT</h5><p>CT-scan should be added in those cases where a cholesteatoma is detected with MRI. CT is needed for preoperative planning (reconstruction of ossicles if needed) and to exclude perforation of the bony tegmen.</p><p>Pars flaccida cholesteatoma originates in <a href="/articles/prussak-space">Prussak's space</a> and usually extends posteriorly.</p><p>Pars tensa cholesteatoma originates in posterior mesotympanum and tends to extend posteromedially.</p><h4>Differential diagnosis</h4><ul>- +</ul><h4>Radiographic features</h4><h5>MRI</h5><p>Conventional non-contrast MR imaging with diffusion-weighted imaging is recommended in all patients with a suspicion of cholesteatoma. An MRI should be performed especially in patients with previous surgery for cholesteatoma since recurrence or residual tumour can be detected with great accuracy. If negative, it can obviate "second look" surgery. It is important to prepare the patient for the examination (clear the external auditory canal or the postoperative cavity) to avoid a false positive diagnosis.</p><p>The standard examination is a T2-weighted series in the coronal and axial plane, followed by a non-echoplanar DWI series (b-values 0, 1000). On the DWI images with b-value 1000 s/mm<sup>2</sup>, a cholesteatoma becomes apparent as a hyperintense area. The signal intensity should be higher than visible on the DWI images with b-value 0 s/mm<sup>2</sup>. On the ADC map, low signal should be visible in the same area, confirming the presence of diffusion restriction.</p><h5>CT</h5><p>A CT scan should be added in those cases where a cholesteatoma is detected with MRI. CT is required for preoperative planning (reconstruction of ossicles if needed) and to exclude perforation of the bony tegmen.</p><p>Pars flaccida cholesteatoma originates in <a href="/articles/prussak-space">Prussak's space</a> and usually extends posteriorly.</p><p>Pars tensa cholesteatoma originates in posterior mesotympanum and tends to extend posteromedially.</p><h4>Differential diagnosis</h4><ul>
-</ul><p>In contrast with cholesteatoma, these show high signal on the ADC map. With these findings, recurrent cholesteatoma can be detected with 100% specificity. Cholesteatomas up to a size of 2 mm can be detected with this technique on a 1.5T machine. </p><p>Further differential diagnosis is to be made with:</p><ul>- +</ul><p>In contrast with cholesteatoma, these show high signal on the ADC map. With these findings, recurrent cholesteatoma can be detected with 100% specificity. Cholesteatomas down to a size of 2 mm can be detected with this technique on a 1.5T MRI machine.</p><p>Further differential diagnosis is to be made with:</p><ul>
-<li>abscess formation in the middle ear: can also show similar imaging findings but has a completely different clinical appearance</li>- +<li>abscess formation in the middle ear: can also show similar imaging findings but has a completely different clinical appearance</li>
-<li>the presence of cholesteatoma in sinus tympani (which is the most hidden recess of the middle ear) - to avoid residual disease</li>- +<li>the presence of cholesteatoma in the sinus tympani (which is the most hidden recess of the middle ear): to avoid residual disease</li>
References changed:
- 7. Rosito L, Netto L, Teixeira A, da Costa S. Classification of Cholesteatoma According to Growth Patterns. JAMA Otolaryngol Head Neck Surg. 2016;142(2):168-72. <a href="https://doi.org/10.1001/jamaoto.2015.3148">doi:10.1001/jamaoto.2015.3148</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/26747599">Pubmed</a>
- 8. Rutkowska J, Özgirgin N, Olszewska E. Cholesteatoma Definition and Classification: A Literature Review. J Int Adv Otol. 2017;13(2):266-71. <a href="https://doi.org/10.5152/iao.2017.3411">doi:10.5152/iao.2017.3411</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/28274903">Pubmed</a>
- 4. Lingam R & Bassett P. A Meta-Analysis on the Diagnostic Performance of Non-Echoplanar Diffusion-Weighted Imaging in Detecting Middle Ear Cholesteatoma: 10 Years On. Otol Neurotol. 2017;38(4):521-8. <a href="https://doi.org/10.1097/MAO.0000000000001353">doi:10.1097/MAO.0000000000001353</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/28195998">Pubmed</a>
- 5. Yung M, Tono T, Olszewska E et al. EAONO/JOS Joint Consensus Statements on the Definitions, Classification and Staging of Middle Ear Cholesteatoma. J Int Adv Otol. 2017;13(1):1-8. <a href="https://doi.org/10.5152/iao.2017.3363">doi:10.5152/iao.2017.3363</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/28059056">Pubmed</a>
- 6. Tono T, Sakagami M, Kojima H et al. Staging and Classification Criteria for Middle Ear Cholesteatoma Proposed by the Japan Otological Society. Auris Nasus Larynx. 2017;44(2):135-40. <a href="https://doi.org/10.1016/j.anl.2016.06.012">doi:10.1016/j.anl.2016.06.012</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/27616746">Pubmed</a>
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