Abstract
In this report, the authors classified the middle ear cholesteatoma as follows;
1) attic cholesteatoma
2) tensa cholesteatoma
3) cholesteatoma behind the intact tympanic membrane
4) implantation cholesteatoma
a) flap cholesteatoma
b) postoperative mastoid cholesteatoma
Five cases of postoperative mastoid cholesteatoma were presented. About these cases, the conditions that was suitable for occurrence of cholesteatoma were discussed.
The authors mentioned that postoperative mastoid cholesteatoma, though generally not observed as common cholesteatoma, was of the same nature as common cholesteatoma.
It was mentioned that when the accelerating factors existed, exfoliation of epithelium occurred and postoperative mastoid cholesteatoma grows in the same mechanism as common cholesteatoma.
In conclusion, the authors suggested that postoperative mastoid cholesteatoma could be one type of the postoperative cholesteatomas.
