Background and Objectives : Gross-pathologicall, there are two types of congenital middle ear cholesteatoma : a closed keratotic cyst and an open matrix. This study aimed to analyzed clinical characteristics of each pathologic type of congenital cholesteatoma and to facilitate better understanding of its pathogenesis.
Materials and Method : We reviewed retrospectively 21 patients seen in the past 6 years between May 1994 to April 2000 who were diagnosed as congenital middle ear cholesteatoma under its definite criteria. This study was done by analyzing the patients' history, drum finding, temporal bone CT finding, operative finding and pathologic finding.
Results : The open type congenital cholesteatoma which usually originated from posterosuperior quadrant of the mesotypanum showed higher degree of hearing loss and more frequent unusual presentation, and detected at an older age than the closed type congenital cholesteatoma.
Conclusion : The pathogenesis of open type congenital cholesteatoma may be different from that of closed type congenital cholesteatoma.