Cartilage grafts mimicking cholesteatoma recurrence on diffusion-weighted magnetic resonance imaging: a case series

BACKGROUND: Cholesteatomas present a high risk for residual and recurrent disease, and the surveillance of post-operative patients can be challenging. Diffusion-weighted magnetic resonance imaging is becoming the preferred method for investigating recidivism; however, false positive imaging findings increase the risk of patients undergoing unnecessary second look surgery. CASE REPORTS: This study reports two patients with false positive diffusion restriction associated with cartilage grafts that mimicked cholesteatoma and resulted in second look surgery with no disease found at operation. This study also discusses the related medical literature, including potential causes of abnormal diffusion restriction and methods to negate this. CONCLUSION: Caution should be exercised when considering second look surgery in the presence of a cartilage graft and a high confidence of disease clearance. A multi-disciplinary approach is recommended for the operating surgeon to review the images with a radiologist.