術後性真珠腫

抄録

Cholesteatoma of the middle ear appearing after surgery is called either recurrent cholesteatoma, residual cholesteatoma or iatrogenic cholesteatoma (Sheehy). The author has encountered such cholesteatomas in 79 cases out of 194 operated cases and classified them as follows:
I Recurrent cholesteatoma
A) retention cholesteatoma
1. cholesteatoma formations due to retraction of the neo-tympanic membrane into the attic space,
2. cholesteatoma formations due to retraction of the posterior wall skin into the mastoid cavity through a hole in the posterior bony wall.
B) invasion cholesteatoma
cholesteatoma formations due to migration of the external canal skin into the middle ear after a loss of the grafted membrane
II Residual cholesteatoma
III Embedded cholesteatoma (iatrogenic cholesteatoma)
Recurrent cholesteatoma often appears in cases where the posterior bony wall is preserved during an operation, and, particularly so, when cholesteatoma develops in the attic space. The author feels it is essential to reconstruct the lateral wall of the attic for prevention of recurrent cholesteatoma