Cholesteatoma Associated With an Isolated Perforation in Shrapnell's Membrane

The importance of a perforation in the upper periphery of the tympanic membrane as contrasted with a central perforation is demonstrated by the statistics of Scheibe1and Schlittler,2who found that 91 per cent of the cases of epitympanic perforation were complicated with cholesteatoma, and that 100 per cent of their cases of chronic suppuration with fatal complications were cholesteatoma. The frequency of a perforation in Shrapnell's membrane attracted the attention of Bezold,3who found that this type comprised 6 per cent of his cases of chronic suppuration. He observed that perforation in this area was almost always associated with a collection of epidermis in the aditus and antrum. The observation that a perforation in the pars flaccida never occurred during genuine or secondary acute suppurations of the middle ear indicated a different etiology from that of perforation or destruction of the pars tensa. The main theories