Learning Objectives:

Introduction: Potsic classification has been widely used as the classification of congenital cholesteatoma. According to this classification, destruction of ossiculs is one of the important points. And the stage will be progressed if the ossicular chain is destructed even in the case of small cholesteatoma which is limited in tympanic cavity. The committee on Nomenclature of the Japan Otological Society (JOS) was appointed in 2004 to create a cholesteatoma staging system widely applicable in Japan and as simple as possible to use in a clinical practice. We introduce our staging system about congenital cholesteatoma.

Methods: A total of 599 ears that underwent surgery for fresh cholesteatoma between 2009 and 2010 at 6 institutions in Japan were recruited and cases with congenital cholesteatoma were selected. In order to know the progress site reliably, we selected strictly the cases which could be obtained surgical records in details. We evaluated the progression of cholesteatoma according to the 2015 JOS cholesteatoma staging and classification system as followed;

Stage I: limited in tympanic cavity (Ia;anterior part, Ib;posterior part, Ic; both of them)

Stage ll: beyond tympanic cavity

Stage III: associated with intratemporal complications

Stage IV: associated with intracranial complications

Results: Seventy one ears of 599 ears were diagnosed for congenital cholesteatoma and 37 ears of 71 have been studied. Six ears were classified for Stage Ia, 11 ears for lb, 1 ear for Ic, 17 ears for II and 2 ears for III. Concerning about the pathology of stapes in Stage l, the missing rate of stapes superstructure was 0%, 54.5% and 100% in Stage Ia, Ib and Ic, respectively.

Conclusions: Congenital cholesteatoma which was limited in tympanic cavity was different in stapes status by the part of existence of cholesteatoma. Especially in this study, Stage Ib was most common in Stage I. Our staging system which is classified from point of the cholesteatoma extent is simple and useful.