ICD-10 Code C72.20 – Malignant neoplasm of unspecified olfactory nerve (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C72.20 – Malignant neoplasm of unspecified olfactory nerve
What it is
C72.20 identifies a malignant tumor arising in the olfactory nerve when the exact side or site is not specified. Use it for documentation of cancer involving this cranial nerve structure.
Clinical signs
Clinical features vary; refer to documentation. Patients may present with reduced or absent smell, nasal obstruction, headache, or neurologic findings if the lesion extends locally.
When to use this code
Use this code when the provider documents a malignant neoplasm of the olfactory nerve and does not specify left or right. It also fits pathology, imaging, or operative reports that identify the olfactory nerve as the primary site. If the record is unclear about laterality or origin, check documentation before assigning a more specific code.
Do not use for
Do not use C72.20 for benign tumors, metastatic disease to the nerve, or lesions clearly arising from another cranial nerve or adjacent nasal structure. Check documentation if the site is described only as the nasal cavity or olfactory region.
Coding tip
Code the unspecified site only when laterality is not documented; otherwise, select the more specific olfactory nerve code.