Cholesteatoma of mastoid, left ear

This code signifies the presence of a cholesteatoma, a destructive, expanding growth of keratinizing squamous epithelium, specifically located within the mastoid bone of the left ear. This lesion can erode bone and lead to complications such as hearing loss, dizziness, and facial nerve paralysis.

Use this code when documentation clearly indicates a cholesteatoma affecting the mastoid process of the left temporal bone. This diagnosis is typically confirmed through otoscopic examination, audiometry, and imaging studies such as CT or MRI scans.

• Ensure laterality is accurately documented; distinguish between left, right, and bilateral involvement.
• Do not confuse with cholesteatoma of the middle ear (H71.1-) or attic (H71.0-), as these have distinct codes.
• Look for associated complications (e.g., hearing loss, labyrinthine fistula) and code them separately if documented.