The epithelial cyst is a late complication of tympanic grafting in tympanoplasty. If left untreated this complication may cause a loss of the neotympanic membrane as in the case with cholesteatoma which is another serious late complication associated with tympanic grafting.
The authors studied 190 cases of tympanoplasty with temporalis fascia grafts and showed that:
1. The overall incidence of epithelial cyst in the 190 cases has been 6.3% with a greater incidence in revision cases 9.6% as compared to 5.6% for initial operation cases.
2. No significant difference in the incidence of epithelial cyst has been noted between the two grafting methods, underlay and overlay methods.
3. The times between the operation and development of the epithelial cyst have ranged from 2 months to 13 months with an average period of 6.2 months.
4. The epithelial cyst has been found to be more frequently seen at the posterior aspect of the tympanic membrane. This fact may reflect a high frequency of surgical insult to the posterior aspect of the tympanic membrane and the posterior wall of the external auditory meatus.
5. The epithelial cyst of the tympanic membrane can be readily removed under magnification in ambulatory patients if found early in its stage.