Background: Cholesterol granuloma of the middle ear is extremely rare in comparison to cholesterol granuloma of the petrous apex but sometimes shows an aggressive course.
Case report: We report herein a case involving a large, aggressive cholesterol granuloma of the middle ear that eroded the middle cranial fossa. A 64-year-old woman presented with pain in the left ear and hearing loss. Cholesterol granuloma was finally diagnosed from diffusion-weighted imaging, and cortical mastoidectomy was performed with canal wall down tympanoplasty type III. Recovery was uneventful recovery and the patient well at the 3-year follow-up.
Conclusion: This case demonstrates the rare but clinically important pathology of aggressive cholesterol granuloma of the middle ear.