J Int Adv Otol 2017; 13(1): 1-8 • DOI: 10.5152/iao.2017.3363

Review

EAONO/JOS Joint Consensus Statements on the
Definitions, Classification and Staging of Middle Ear
Cholesteatoma
Matthew Yung, Tetsuya Tono, Ewa Olszewska, Yutaka Yamamoto, Holger Sudhoff, Masafumi Sakagami,
Jef Mulder, Hiromi Kojima, Armağan İncesulu, Franco Trabalzini, Nuri Özgirgin
The Ipswich Hospital NHS Trust, Heath Road, Suffolk, United Kingdom IP4 5PD (MY)
Department of Otolaryngology-Head and Neck Surgery, University of Miyazaki 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan (TT)Department of Otolaryngology, Medical University of Bialystok ul. Sklodowskiej 24 A, 15-276 Bialystok, Poland (EO)
Department of Otorhinolaryngology, Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan (YY)
Department of Otorhinolaryngology, Bielefeld Academic Teaching Hospital, Bielefeld, Germany (HS)
Department of Otolaryngology, Hyogo College of Medicine, Hyogo, Japan (MS)Philip van Leydenlaan 15 Radboud University Hospital, 6500 HB Njmegen, Netherlands (JM)
Department of Otorhinolaryngology, Jikei University School of Medicine, 3-25-8 Nishishinbashi,
Minatoku, Tokyo 105-8461, Japan (HK)
Department of Otolaryngology-Head and Neck Surgery, Eskişehir Osmangazi University School of Medicine, Eskişehir, Turkey (Aİ)
Department of Otolaryngology, Meyer Children's Hospital, Florence, Italy (FT)
Department of Otolaryngology, Bayındır Hospital, Ankara, Turkey (NÖ)

The European Academy of Otology and Neurotology (EAONO) has previously published a consensus document on the definitions and classification of cholesteatoma. It was based on the Delphi consensus methodology involving the broad EAONO membership. At the same time,
the Japanese Otological Society (JOS) had been working independently on the “Classification and Staging of Cholesteatoma.” EAONO andJOS then decided to collaborate and produce a joint consensus document. The EAONO/JOS joint consensus on “Definitions, Classificationand Staging of Middle Ear Cholesteatoma” was formally presented at the 10th International Conference on Cholesteatoma and Ear Surgery in
Edinburgh, June 5–8, 2016. The international otology community who attended the consensus session was given the chance to debate andgive their support or disapproval. The statements on the “Definitions of Cholesteatoma” received 89% approval. The “Classification of Cholesteatoma” received almost universal approval (98%). The “EAONO/JOS Staging System on Middle Ear Cholesteatoma” had a majority of approval(75%). Some international otologists wanted to see more prognostic factors being incorporated in the staging system. In response to this, the
EAONO/JOS steering group plans to set up an “International Otology Outcome Working Group” to work on a minimum common otology data
set that the international otology community can use to evaluate their surgical outcome. This will generate a large database and help identify
relevant prognostic factors that can be incorporated into the staging system in future revisions.
KEYWORDS: Definitions, classification, staging, cholesteatoma

The aims of the European Academy of Otology and Neurootology/Japan Otological Society (EAONO/JOS) Joint Consensus Statements on Definition, Classification and Staging are as follows:
1.
2.
3.

The definitions provide terminologies in the description of cholesteatoma.
The classification categorized cholesteatoma into distinct categories to facilitate the comparison of surgical outcomes acrossreports.
The staging system reflects the severity of the cholesteatoma, the difficulty to achieve complete removal, and the subsequent
restoration of normal function.

The authors wish to present the final consensus first, followed by an explanation of the methodology on how the EAONO/JOS consensus was reached by the steering group.
The clinical classification of middle ear mucosa is summarized in Figure 1.
Corresponding Address: Matthew Yung E-mail: matthewyung@btconnect.com
Submitted: 12.12.2016
Accepted: 15.12.2016
Available Online Date: 06.01.2017©Copyright 2017 by The European Academy of Otology and Neurotology and The Politzer Society - Available online at www.advancedotology.org

1

J Int Adv Otol 2017; 13(1): 1-8

Definitions and Statements on Cholesteatoma
1.

Cholesteatoma is a mass formed by the keratinizing squamous epithelium in the tympanic cavity and/or mastoid and subepithelial connective tissue andby the progressive accumulation of keratin debris with/without a surrounding inflammatory reaction.

2.

Cholesteatoma consists of matrix (keratinizing squamous epithelium), perimatrix (varying thickness of the subepithelial connective tissue), and keratin
debris.

3.

The pathophysiology of cholesteatoma is not completely understood.

4.

Recurrent infections and inflammatory reactions at the subepithelial connective tissue of cholesteatoma contribute to bone resorption in the adjacent
area.

5.

Cholesteatoma is diagnosed with a detailed otologic history, physical examination by otomicroscopy, and endoscopy with or without imaging.

6.

Cholesteatoma is classified into two general categories: congenital and acquired.

7.

Acquired cholesteatoma is characterized by clinical symptoms/signs that are the result of growth with/without destruction of the adjacent structures:- with or without tympanic membrane retraction and/or perforation,- with or without otorrhea,- with or without hearing deterioration,
and/or CT/MRI findings (soft tissue masses, focal areas of bony erosion of the middle ear, and mastoid)
8.

A retraction pocket can develop into acquired cholesteatoma when it loses its ability of self-cleaning and starts the accumulation of keratin debris.

9.

Acquired cholesteatoma is not present at birth.

10. Acquired cholesteatoma might develop from a retraction pocket of the pars flaccida, pars tensa, or both and from basal cell invasion through the basilar
membrane and could be a sequela of the dysfunction of middle ear pressure regulation. Acquired cholesteatoma can also develop secondary to tympanic membrane perforation as a result of previous chronic otitis media, trauma, or iatrogenic causes.
11. Congenital cholesteatoma is typically an expanding cystic mass with keratinizing squamous epithelium located medial to the intact tympanic membrane, is assumed to be present at birth, but is usually diagnosed during infancy or in early childhood in patients with no prior history of otorrhea,
perforation, or previous ear surgery.
12. A history of previous bouts of otitis media or an effusion does not exclude congenital cholesteatoma.
13. Congenital cholesteatoma is usually located at the anterosuperior quadrant of the middle ear. However, it may be located at the posterosuperior quadrant or other locations.
14. The clinical presentation of congenital cholesteatoma is determined by the location and extent of the lesion. It may be characterized by-± a white mass medial to an intact tympanic membrane,-± hearing loss when enlarged to fill the middle ear or erodes the ossicles,-± extremely rarely with pain,
and/or CT/MRI findings (usually as a round soft tissue mass at the anterosuperior quadrant, the posterosuperior quadrant, or other locations)
15. Cholesteatoma recidivism includes both residual and recurrent cholesteatoma. It is essential to differentiate them.
16. Residual cholesteatoma results from the incomplete surgical removal of the cholesteatoma matrix.
17. Recurrent cholesteatoma results from the reformation of the retraction pocket after a complete previous surgical cholesteatoma removal.
18. Cholesteatoma is classified into acquired, congenital, and unclassifiable (cholesteatoma whose origin cannot be accurately determined).
Acquired cholesteatoma is further subclassified into
1. retraction pocket cholesteatomaa)pars flaccida (attic cholesteatoma)b) pars tensa cholesteatomac)combination of pars flaccida and pars tensa cholesteatoma

2. non-retraction pocket cholesteatomaa)cholesteatoma secondary to tympanic perforation (the so-called secondary acquired cholesteatoma)b) cholesteatoma following trauma and/or otologic procedures
Post-surgical cholesteatoma may be residual or recurrent, although these are not mutually exclusive.

2

Yung et al. EAONO/JOS Classification and Staging of Cholesteatoma

CHOLESTEATOMACONGENITALACQUIREDRETRACTION POCKETCHOLESTEATOMAUNCLASSIFIABLE

NON-RETRACTION POCKETCHOLESTEATOMA

Secondary to TM
Perforation

Pars tensa cholesteatoma
Pars flaccida
cholesteatoma

Following trauma or
iatrogenic causes

Combination of pars flaccidaand pars tensa cholesteatoma
Post surgery

Not mutually exclusive

Recurrent cholesteatoma

Residual cholesteatoma

Figure 1. Schematic drawing of the clinical classification of middle ear cholesteatoma

Divisions of the middle ear space using the STAM system is illustrated
in Figure 2.
2. The EAONO/JOS staging system applies to four types of middle
ear cholesteatoma(Pars flaccida cholesteatoma, pars tensa cholesteatoma, congenitalcholesteatoma, and cholesteatoma secondary to a tensa perforation)

Figure 2. Divisions of the middle ear space using the STAM system

Stage I: Cholesteatoma localized in the primary site** The site of cholesteatoma origin, i.e., the attic (A) for pars flaccida
cholesteatoma; the tympanic cavity (T) for pars tensa cholesteatoma,congenital cholesteatoma, and cholesteatoma secondary to a tensa
perforation

Staging of Middle Ear Cholesteatoma

Stage II: Cholesteatoma involving two or more sites

1. Divisions of the middle ear space (STAM system)
In order to simplify the extent of cholesteatoma, the middle ear andmastoid space are divided into four sites: difficult access sites (S), tympanic cavity (T), attic (A), and mastoid (M). The difficult access sites (S)includes S1, the supratubal recess (also called the anterior epitympanum or protympanum) and S2, the sinus tympani. The posteriorborder of the attic is the posterior end of the incus short process or
the fossa incudis. The mastoid includes the antrum and mastoid cells.

Stage III: Cholesteatoma with extracranial complications or
pathologic conditions including
Facial palsy,
Labyrinthine fistula: with conditions at risk of membranous labyrinth,Labyrinthitis,
Postauricular abscess or fistula,
Zygomatic abscess,
Neck abscess,3

J Int Adv Otol 2017; 13(1): 1-8

Canal wall destruction: more than half the length of the bony ear canal,
Destruction of the tegmen: with a defect that requires surgical repair, andAdhesive otitis: total adhesion of the pars tensa.
Stage IV: Cholesteatoma with intracranial complications including
Purulent meningitis,
Epidural abscess,Subdural abscess,Brain abscess,Sinus thrombosis, andBrain herniation into the mastoid cavity.
The staging system does not apply to petrous bone cholesteatoma.
3.
1)

Staging systems for respective cholesteatoma types
Pars flaccida cholesteatoma (attic cholesteatoma)
Stage I: Cholesteatoma localized in the attic
Stage II: Cholesteatoma involving two or more sites
Stage III: Cholesteatoma with extracranial complications
Stage IV: Cholesteatoma with intracranial complications

2)

Pars tensa cholesteatoma, cholesteatoma secondary to a tensa
perforation, and congenital cholesteatoma
Stage I: Cholesteatoma localized in the tympanic cavity
Stage II: Cholesteatoma involving two or more sites
Stage III: Cholesteatoma with extracranial complications
Stage IV: Cholesteatoma with intracranial complications

tively, these 10 members produced the first draft of the document
by consensus (Draft 1).
b.
1.

Consensus among steering group members (Draft 1):
Definitions of Cholesteatoma-The definitions provide terminologies in the description of cholesteatoma. Except for someminor changes in the narratives, the original EAONO statements
on definitions of cholesteatoma were adopted. These changes
include· The revised EAONO/JOS statement “Congenital cholesteatoma
is usually located at the anterosuperior quadrant of the middle
ear. However, it may be located at the posterosuperior quadrant or other locations” is an amendment to the original EAONO
statement to reflect the fact that many congenital cholesteatomas in Japan were found at the posterosuperior quadrant.
· The term “chronic otitis media with or without cholesteatoma”
in the original 2015 EAONO document was dropped from thejoint consensus as the term is not universally accepted.

2.

Classification of Middle Ear Cholesteatoma-The classification
categorized cholesteatoma into distinct categories to facilitate
the comparison of surgical outcome across reports. The classification proposed originally by EAONO and JOS independently
were compared, modified, and merged:· The terms “primary acquired” and “secondary acquired” were
dropped as they are historical terms and are confusing. In the
joint EAONO/JOS classification, acquired cholesteatoma wasdivided into retraction pocket cholesteatoma and non-retraction pocket cholesteatoma.
· The joint EAONO/JOS classification applies only to “Middle
Ear Cholesteatoma” as the inclusion of petrous cholesteatoma
makes the classification and staging system too complex.
· Cholesteatoma was classified as “congenital,” “acquired,” and“unclassifiable.” The last category was not present in the original 2015 EAONO classification. In certain large or open cholesteatomas, it may not be possible to ascertain whether they are“congenital” or “acquired.”· “Suspected congenital cholesteatoma” from the original JOS
classification was dropped.

3.

Staging of Middle Ear Cholesteatoma-The staging system reflects the severity of the cholesteatoma, the difficulty to achievecomplete removal, and the subsequent restoration of the normal function. The EAONO/JOS steering group modified theoriginal JOS staging system and adopted the new version as the
EAONO/JOS staging system.
· “Retraction pocket” was dropped from the original JOS staging system because it is not cholesteatoma by definition.
· Stages 1 and 2 are based on sites of cholesteatoma involvement. Stage 2 represents the involvement of multiple sites.
· The original sites of protympanum, tympanic cavity, attic, andmastoid proposed by JOS (symbolized as PTAM as illustrated
in Figure 3) were changed to STAM (S1: supratubal recess, S2:sinus tympanum, tympanic cavity, attic, and mastoid) in the
joint EAONO/JOS staging system.
· Stage 3 represents extracranial extension, and stage 4 represents intracranial extension. These extensions are specified
in the joint EAONO/JOS staging system.

Background on the Collaboration Between EAONO and JOS on the
Definitions, Staging, and Classification of Middle Ear Cholesteatoma
The European Academy of Otology and Neurotology (EAONO) has
previously published a document on the definitions and classification of cholesteatoma. They were published in 2015 and are summarized in Appendix 1[1]. The statements were based on the Delphi consensus methodology involving the broad EAONO membership. At
the same time, the Japan Otological Society (JOS) had been working
independently on the “Classification and Staging of Cholesteatoma.”Its recommendations were formulated by the JOS steering board
alone and are summarized in Appendix 2[2-15].
The respective steering group of EAONO and JOS decided to work
together to produce a single consensus document on the “Definitions, Classification, and Staging of Middle Ear Cholesteatoma” toglobalize the system. The first EAONO/JOS steering group meeting
was held in 2015 at the 30th Politzer Society Meeting in Niigata. The
final version of the “Joint EAONO/JOS Consensus on the Definitions,Classification, and Staging of Middle Ear Cholesteatoma” was theend product of many rounds of discussions and refinements over a
12-month period.
Formulation of a Joint EAONO/JOS Consensus on the Definitions,Classification, and Staging of Middle Ear Cholesteatoma
a. Methodology
Six European otologists of the original EAONO steering group(Matthew Yung, Ewa Olszewska, Nuri Özgirgin, Holger Sudhoff, Jef
Mulder, and Armağan İncesulu) and four Japanese otologists of theoriginal JOS steering group (Tetsuya Tono, Masafumi Sakagami,
Yutaka Yamamoto, and Hiromi Kojima) participated in the joint EAONO/JOS steering group to work on the consensus project. Collec-

4

Yung et al. EAONO/JOS Classification and Staging of Cholesteatoma

International Feedback of the Proposed EAONO/JOS Consensus
The 10th International Conference on Cholesteatoma and Ear Surgery,
June 5–8, 2016 (Chole2016) provided the opportunity for the EAONO/JOS steering group to gauge the international acceptance of the proposed EAONO/JOS “Definitions, Classification, and Staging of Middle
Ear Cholesteatoma.” Over 1000 delegates from 54 countries attended
Chole2016, with 23 national otology societies presenting mini-symposia. The EAONO/JOS steering group went through several rounds ofinternational feedback assist in producing the final version.
a. One month before Chole2016, the draft EAONO/JOS consensus document was sent to the presidents and/or the representatives of various national otology societies. Specificcomments were received from the British Society of Otology,
American Otological Society, Australian Otological Society,
German HNO, and Canadian Otological Society. They were
mostly in agreement with the EAONO/JOS proposal and only
minor adjustments were made in response to these comments (Draft 2).
b. Draft 2 of the EAONO/JOS consensus document was formallypresented at a consensus session at Chole2016 (Staging andClassification of Cholesteatoma). The delegates present at
the consensus session were given the chance to debate andcomment on the definitions, classification, and staging of the
proposed document section by section. Their feedback wasrecorded, considered, and refinement was made to the document (Draft 3).
c. As it took a few days for the EAONO/JOS steering group to
produce Draft 3 in response to the comments received at
Chole2016, the delegates were invited to provide follow up
feedback later on. Those agreed to be contacted again had
their ID code (on the conference badge) scanned. Draft 3
was then sent to each international delegate together witha standardized feedback form electronically. Their approval/
disapproval of Draft 3 and the reasons for disapproval wererecorded.
d. Analysis of international feedback on the “Definitions of Cholesteatoma” (Table 1).
Altogether, 47 international delegates provided follow up feedback
on Draft 3. Of these, 3 were trainee otolaryngologists. Their responses were, therefore, excluded from the analysis.
Eighty-nine percent of the international delegates gave their approval to the statements on definition. Five (5) comments were given as
the reason for disapproval:
1.

2.

Reason given by one UK delegate: On Terminology-commented thatthe title should be specified as “Middle Ear Cholesteatoma.”The EAONO/JOS steering group agreed and made the change as suggested.
Reason given by one Australian delegate: On Terminology-theterm “middle ear and mastoid” in Statement 1 should bechanged to “tympanic cavity and mastoid.” This was thought
to be reasonable and change was made accordingly. The samedelegate also proposed to incorporate petrous cholesteatoma
as a form of congenital cholesteatoma. The EAONO/JOS steeringgroup did not agree to making such a change because not all
petrous cholesteatomas are congenital.

Table 1. International comments on EAONO/JOS Definitions of Cholesteatoma at
Chole 2016 (44 responses)
		
Number ofCountry
responses

Approveproposeddefinitions

Disapprove
proposeddefinitions

UK

7

6

1

Japan

8

8

0

Sweden330Australia

312Bulgaria220Denmark2

2

0

Netherland

2

2

0

Italy

2

2

0

Poland2

1

1

New Zealand

2

2

0

Switzerland

1

1

0

Brazil101Norway1

10

Russia1

10Algeria

1

1

0

India

1

1

0

France110Singapore110South Africa

1

1

0

Vietnam

1

1

0

Spain

1

1

0

Total =

Total = 44

Total = 39 (89%)

Total = 5 (11%)

3.
4.

5.

No reason given from another Australian delegate.
Reason given by one Polish delegate: On Terminology-the term
“middle ear and mastoid” in Statement 1 should be changed to“tympanic cavity and mastoid.” This was thought to be reasonable and was amended accordingly.
Reason given by one Brazilian delegate: Two of the statements
in Draft 3 were repetitive and the delegate recommended oneof them to be deleted. The EAONO/JOS agreed and deleted oneof the statements.

All the above amendments were regarded as minor and the EAONO/JOS steering group felt that they did not change the essence of the“Definitions of Middle Ear Cholesteatoma.”e. Analysis of international feedback on the “Classification ofCholesteatoma” (Table 2).
It was very encouraging to see 98% of the international delegatesgave their approval on the “Classification of Middle Ear Cholesteatoma.” The single comment provided by an Australian delegate that led
to the disapproval was
1.

Advised relegating “cholesteatoma secondary to perforation”
to “others” as it is rare. EAONO/JOS decided against making thischange.

5

J Int Adv Otol 2017; 13(1): 1-8

Table 2. International comments on the EAONO/JOS Classification ofCholesteatoma at Chole 2016 (44 responses)

Table 3. International comments on the EAOBO/JOS Staging ofCholesteatoma at Chole 2016 (44 responses)

		
Number ofCountry
responses

		
Number ofCountry
responses

Approveproposeddefinitions

Disapprove
proposeddefinitions

Approveproposeddefinitions

Disapprove
proposeddefinitions

UK

7

7

0

UK

7

5

2

Japan

8

8

0

Japan

8

8

0

Sweden3

30

Sweden330Australia

321Australia

312Bulgaria

220Bulgaria2

1

1

Denmark2

2

0

Denmark2

2

0

Netherland

2

2

0

Netherland

2

1

1

Italy

2

2

0

Italy

2

1

1

Poland220Poland2

20

New Zealand

2

2

0

New Zealand

2

2

0

Switzerland

1

1

0

Switzerland

1

0

1

Brazil1

10Brazil1

10Norway1

10Norway101

Russia1

10

Russia1

10Algeria1

10Algeria

1

0

1

India

1

1

0

India

1

1

0

France1

10France110Singapore110Singapore110South Africa

1

1

0

South Africa

1

0

1

Vietnam110Vietnam

1

1

0

Spain

1

1

0

Spain

1

1

0

Total =

Total = 44

Total = 43 (98%)

Total = 1 (2%)

Total =

Total = 44

Total = 33 (75%)

Total = 11 (25%)

f. Analysis of international feedback on the “Staging of Cholesteatoma” (Table 3).
The EAONO/JOS Staging System on Middle Ear Cholesteatoma received most comments during the consensus session at Chole2016.
The debate was mainly on whether it should be simple but easy touse, or more complex to include more prognostic factors. It was,therefore, not surprising that it received less consensus compared tothe sections on definitions and classification. Nevertheless, 75% of
the international delegates approved the staging system. There were
11 delegates who did not approve the proposed consensus on staging. Their comments were summarized into several themes:
Figure 3. Divisions of the middle ear space using the PTAM system

1.

2.

6

The proposed EAONO/JOS staging system was thought by someto be too simplistic. Several responders suggested a TNM style
staging system to incorporate other prognostic factors that may
influence surgical outcome (Netherland, 1; UK, 1; Switzerland, 1;
Norway, 1; and Algeria, 1). Several other responders suggested increasing the number of stages, i.e., more than 4 stages to accommodate more prognostic factors (UK, 1; Italy, 1; South Africa, 1.)
On the other hand, one responder (Australia, 1) proposed analternative staging system that was even simpler than the EAONO/JOS staging system. This was at odds with the others whowanted a more complex system.

3.

4.

One responder (Bulgaria, 1) recommended changing the term
“tensa perforation” to “tympanic perforation” to include parsflaccida as well. This was felt to be reasonable and the change
was made accordingly.
One responder suggested incorporating petrous cholesteatoma
back into the system (Australia, 1). The steering group did not makethe change as it made the staging system even more complicated.

Amongst the 11 responders who did not give approval to the EAONO/JOS “Staging of Middle Ear Cholesteatoma,” most were concernedYung et al. EAONO/JOS Classification and Staging of Cholesteatoma

Original EAONO consensus on the
Definitions and Classification ofCholesteatoma (Based on Delphi method
involving broad EAONO membership)

Original JOS Classification andStaging of Cholesteatoma (Based on
Committee opinion)

EAONO/JOS joint consensus
on Definitions, Classificationand Staging of Middle Ear
Cholesteatoma (Based on
Committee opinion) – DRAFT 1

Feedback from representativesof National Otological Societies(5 Societies) – DRAFT 2

Feedback following debatesat Consensus Session at
Chole2016 – DRAFT 3

Feedback from international
otologists (44 responders from
21 countries) –FINAL DOCUMENT
Figure 4. Schematic illustration of the consensus process of the joint EAONO/JOS document on the Definitions, Classification and Staging of Middle Ear Cholesteatoma

about its over-simplicity. Five out of eight recommended a TNM stylesystem to incorporate other parameters such as ossicular status,
mucosal status, and pneumatization of the mastoid cells. Three outof eight recommended increasing the number of stages within thesystem to incorporate extra parameters. However, these responders
could not agree as to which parameters should be included as there
is a lack of evidence or consensus in the literature. The EAONO/JOS
steering group felt that a more complex staging system may result ineven more controversy. Therefore, the staging system was kept simple at this stage and other prognostic factors may be incorporated in
the future only if they are supported by evidence.

staging system. In response to this criticism, the EAONO/JOS steering group plans to set up an “International Otology Outcome Working Group” under the auspices of the Politzer Society. The aim of thatgroup is to agree on a minimum common otology data set that theinternational otology community can use to evaluate their surgicaloutcomes. The steering group will facilitate multi-center studies witha large database to identify relevant prognostic factors that could beincorporated into a future revised EAONO/JOS staging system. Suchparameters will then be based on evidence and not on personal opinion or sentiment.

The method in reaching the final version of the EAONO/JOS consensus document is summarized in Figure 4.
Plan for the future
The “EAONO/JOS Consensus on Definitions of Middle Ear Cholesteatoma” received 89% international approval. Minor alterations weremade that did not alter the essence of the document. The final “EAONO/JOS Consensus Document on the Classification of Middle Ear Cholesteatoma” received almost universal international approval (98%).
The “EAONO/JOS Staging System on Middle Ear Cholesteatoma” hada majority of international approval (75%). Some international otologists wanted to see more prognostic factors incorporated into the

Author Contributions: Concept – M.Y., T.T., E.O., Y.Y., H.S., M.S., J.M., H.K., A.İ.,
F.T., N.Ö.; Design – M.Y., T.T., E.O., H.S., J.M., H.K., N.Ö.; Supervision – M.Y., T.T.,
N.Ö.; Resources - M.Y.; F.T., N.Ö.; Data Collection and/or Processing - M.Y., T.T.,
E.O., Y.Y., H.S., M.S., J.M., N.Ö.; Analysis and/or Interpretation - M.Y., T.T., E.O.,
Y.Y., H.S., M.S., J.M., N.Ö.; Literature Search – E.O.; Writing Manuscript – M.Y.,
T.T., E.O.; Critical Review – M.Y., T.T., E.O., Y.Y., H.S., M.S., J.M., H.K., A.İ., F.T., N.Ö.

Peer-review: Externally peer-reviewed.

Acknowledgements: The JOS staging system has been developed mainly
through the committee based consensus process, with the current committee members, Tetsuya Tono, Masafumi Sakagami, Yutaka Yamamoto, Hiromi
Kojima, Keiji Matsuda, Manabu Komori, Naohito Hato, Yuka Morita and Sho
Hashimoto and the former committee members, Makito Okamaoto, Masaru

7

J Int Adv Otol 2017; 13(1): 1-8

Aoyagi, Tsukasa Ito, Hiroshi Hosoi, Takashi Nakagawa, Taeko Okuno, Yasuyuki
Hinohira and Yasuo Mishiro. They acknowledge the contribution of JOS members to the vigorous cultivation of the JOS staging system over the past eight
years. The criteria set has been approved by the JOS Board of Directors.

7.

Conflict of Interest: No conflict of interest was declared by the authors.

9.

8.

Financial Disclosure: Credit is given to Professor Naoaki Yanagihara for initiating the collaboration between EAONO and JOS.

REFERENCES
1.

2.

3.

4.

5.

6.

8

Olszewska E, Rutkowska J, Özgirgin N. Consensus-Based Recommendations on the Definition and Classification of Cholesteatoma. J Int Adv
Otol 2015; 11: 81-7. [CrossRef]
Matsuda K, Tono T, Kojima H, Yamamoto Y, Sakagami M, Mishiro Y, et al.
Practicality analysis of the staging system proposed by the Japan Otological Society for acquired middle ear cholesteatoma: A multicenter
study of 446 surgical cases in Japan. Auris Nasus Larynx 2016.
Kojima H, Yohsida R, Shiwa M, Tanaka Y, Moriyama H. Evaluation of Classification and Staging of Cholesteatoma proposed in 2008 (Japan Otology
Society) in pars flaccida cholesteatoma. Otol Jpn 2010; 20: 677-83.
Ota T, Matsui K, Kure K, Naitou S, Miyoshi Y. Evaluation of the hearing
results after tympanoplasty according to the classification of the development degree for attic cholesteatoma Otol Jpn 2010; 20: 164-72.
Kitahara T, Mishiro Y, Sakagami M, Kamakura T. Staging-based surgicalresults in chronic otitis media with cholesteatoma. Nippon Jibiinkoka
Gakkai Kaiho (Tokyo) 2012; 115: 91-100. [CrossRef]
Morita Y, Yamamoto Y, Oshima S, Takahashi K, Nemoto M, Kuwabara Y, et
al. Comparison of pathology between pars flaccida cholesteatoma andpars tensa cholesteatoma based on the staging criteria for cholesteatoma 2010 Japan. Otol Jpn 2013; 24: 113-7.

10.

11.

12.

13.

14.

15.

Hasegawa K, Kunimoto Y, Yazama H, Kuya J, Kitano H. Hearing evaluation after cartilage tympanoplasty for acquired cholesteatoma. Otol Jpn
2014; 24: 233-9.
Yoshida T, Sone M, Kato K, Nakashima T. An analysis of primary acquired
middle ear cholesteatoma Otol Jpn 2014; 24: 227-32.
Morita Y, Yamamoto Y, Oshima S, Takahashi K, Nemoto M, Kuwabara Y, et
al. Comparison of surgical treatment and outcomes between pars flaccida cholesteatoma and pars tensa cholesteatoma based on the staging
criteria for cholesteatoma 2010 Japan. Otol Jpn 2014; 24: 181-7.
Hasegawa K, Kunimoto Y, Yazama H, Kuya J, Kitano H. Hearing evaluation after cartilage tympanoplasty for acquired cholesteatoma. Otol Jpn
2014; 24: 233-9.
Yamamoto Y. Current state of usage of the Classification and Staging System of Cholesteatoma proposed by the Japan Otological Society. Otol
Jpn 2015; 25: 160-3.
Sato S, Suzuki R, Ohno T, Yoshida A. Evaluation of hearing after tympanoplasty for pars tensa cholesteatoma according to Japan OtologicalSociety guidelines. Otol Jpn 2015; 25: 19-24.
Miyahara N, Fukushima N, Hirai T, Miyoshi A, Ariki M. Clinical featuresof the pediatric acquired cholesteatoma based on the Staging Criteria
for Cholesteatoma 2010 Japan. Nippon Jibiinkoka Gakkai Kaiho (Tokyo)
2016; 119: 181-6. [CrossRef]
Morita Y, Yamamoto Y, Oshima S, Takahashi K, Takahashi S. Pediatric middle ear cholesteatoma: the comparative study of congenital cholesteatoma and acquired cholesteatoma. Eur Arch Otorhinolaryngol 2016; 273:
1155-60. [CrossRef]
Tono T, Sakagami M, Kojima H, Yamamoto Y, Matsuda K, Komori M, etal. Staging and classification criteria for middle ear cholesteatoma proposed by the Japan Otological Society. Auris Nasus Larynx in press, available online at http://dx.doi.org/10.1016/j.anl.2016.06.012. [CrossRef]