Findings:
The ear pinna is unremarkable. There is soft tissue thickening along the cartilaginous and bony left external auditory canal, particularly posteriorly, with associated erosion of the adjacent anterior, posterior and inferior walls of the left EAC. Posteriorly the lesion extends into the adjacent mastoid air cells.
The tympanic membrane on the left side is mildly thickened with medial bowing. The scutum appears to be intact.
The middle ear, vestibular-cochlear apparatus and internal acoustic canal have a normal appearance. The vestibular aqueduct is normal size.
The course of the facial nerve is normal.
The carotid canal and jugular foramen are unremarkable.
Minimal fluid is seen in several mastoid air cells in the right mastoid process. No further abnormality can be observed on the right side.
Mucosal thickening is seen in the right maxillary sinus. The paranasal sinuses are otherwise clear.
Impression:
The findings of CT suggest external auditory canal cholesteatoma.