Aim: The aim of this study is to gain insight into the disease progression and behavior of primary cholesteatoma in a cohort of patients who did not have surgery using non-echoplanar diffusion-weighted magnetic resonance imaging (DW MRI) serial monitoring.
Methods: Retrospective longitudinal observational study of 12 cases of middle ear cleft cholesteatoma diagnosed between 2009 and 2014 where surgery was not performed for various reasons. All cases were monitored radiologically with non-echoplanar half-Fourier acquisition single-shot turbo spin-echo diffusion weighted imaging annually for a median period of 23 months (between 11 and 45 mo) to evaluate for changes in disease volume and direction of growth.
Results: Of the 12 cases, there was one outlier where the cholesteatoma growth was disproportionately high compared with the rest of the cases outside the standard deviation range. A third of the cases had radiological evidence of cholesteatoma growth. The mean growth was about 11.9% of the initial disease volume per year. Seven out of the 12 cases had radiological evidence of cholesteatoma regression in terms of size, with three cases having negative follow-up DW-MRI scans as early as 17 months. The mean regression rate was much higher than the mean growth rate at 54.3% of the initial disease volume per year. The direction of greatest growth is craniocaudally.
Conclusion: Within the limits of our longitudinal study, we have shown that by monitoring with non-echoplanar diffusion weighted imaging, cholesteatoma can progress or regress when left untreated by surgery. The greatest progression was recorded in the craniocaudal direction.