ICD-10 Code C72.42 – Malignant neoplasm of left acoustic nerve (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C72.42 – Malignant neoplasm of left acoustic nerve
What it is
C72.42 identifies a malignant tumor involving the left acoustic nerve, also called the vestibulocochlear nerve. Use it when documentation clearly states cancer of the left acoustic nerve or a malignant neoplasm in that exact location.
Clinical signs
Clinical features vary; refer to documentation. Hearing loss, tinnitus, dizziness, or balance problems may appear, but you should code the documented diagnosis rather than symptoms alone.
When to use this code
Use C72.42 when the provider documents a malignant neoplasm of the left acoustic nerve, including confirmed primary or site-specific cancer wording. It may also apply when pathology, imaging, or specialist notes clearly identify the left acoustic nerve as the involved site. If the record only says “brain tumor” or “acoustic neuroma” without malignant wording, check documentation.
Do not use for
Do not use this code for benign acoustic neuroma, unspecified laterality, or symptoms such as hearing loss without a documented malignant neoplasm. Check documentation if the site or behavior is unclear.
Coding tip
Capture laterality exactly as documented; left-sided disease belongs in C72.42, not an unspecified or right-sided code.