上鼓室外側壁から外耳道上壁破壊を主病変とした真珠腫後遺症の一例

抄録

Epitympanic retraction cholesteatoma is a rather frequently encountered variety of chronic otitis media in which the invagination of Schrapnell's membrane takes place in the attic with disturbed aeration. This disturbed aeration is caused by tubal occlusion or an inadequate ventilation of the middle ear as seen in longstanding secretory otitis media. A cholesteatoma is characterized by resolving the adjacent bony structure. In cases with extended cholesteatoma, the superior wall of the external auditory canal is involved, the scutum is often eroded. We report a case of cholesteatoma in which an unusual growth pattern was observed. In this case, the epitympanic retraction cholesteatoma has projected down straight to erode the superior wall of the external auditory meatus without a significant extension to the middle ear cleft.