Cholesteatoma growth patterns: are there audiometric differences between posterior epitympanic and posterior mesotympanic cholesteatoma?

The objective of this is to verify whether the hearing impairment caused by posterior epitympanic differed from that caused by posterior mesotympanic cholesteatomas by a cross-sectional study. We evaluated 264 ears of patients with cholesteatoma, who had not been subjected to ear surgery. Otoendoscopy and pure-tone audiometry were performed. Analyzed route involved in cholesteatoma formation: posterior epitympanic or posterior mesotympanic, air-bone gaps at 512-4000 Hz and pure-tone averages. The mean age of the patients enrolled in this study was 33.8 years, and 51.8 % of them was male. Posterior epitympanic cholesteatoma was found in 50.4 % of the study population. When the air-bone gaps were compared, the mesotympanic group had greater thresholds at 500, 2000 Hz, and a greater pure-tone average (P = 0.003, P = 0.03, and P = 0.02, respectively). Posterior mesotympanic cholesteatoma showed greater air-bone gaps thresholds at the speech frequencies than posterior epitympanic cholesteatoma did. Moreover, the two growth patterns were very similar with regard to all other audiometric parameters analyzed in this study.