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.

OBJECTIVE: The Objective of this study was to assess the practicality of the cholesteatoma staging system proposed by the Japan Otological Society (JOS) for acquired middle ear cholesteatoma (the 2010 JOS staging system).

METHODS: Between 2009 and 2010, 446 ears with retraction pocket cholesteatoma underwent primary surgery at 6 institutions in Japan. The extent of cholesteatoma was surgically confirmed, and classified into three stages.

RESULTS: The cholesteatoma affected the pars flaccida in 325 ears (73%), the pars tensa in 100 ears (22%), and both regions combined in 21 ears (5%). The hearing outcome (postoperative air-bone gaps dB) worsened as follows (Stage I, II, III): 84%, 68%, 53% in pars flaccida; 71%, 62%, 30% in pars tensa, and 42% at Stage II, and 50% at Stage III in the combined group. The incidence of residual cholesteatoma increased as follows (Stage I, II, III): 2%, 12%, 23% in pars flaccida; 7%, 30%, 21% in the pars tensa group. The severity of disease was reflected in postoperative hearing and increasing incidence of recurrence rate.

CONCLUSION: The 2010 JOS staging system is suitable for evaluating initial pathology. It is particularly practical for standardizing reporting of retraction pocket cholesteatoma and for adjusting for the severity of the condition during outcome evaluations. It may also provide information that is useful for counseling patients.