ICD-10 Code C11.9 – Malignant neoplasm of nasopharynx, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C11.9 – Malignant neoplasm of nasopharynx, unspecified
What it is
C11.9 identifies a malignant tumor arising in the nasopharynx when the specific site or histology is not further documented. Use it for a confirmed nasopharyngeal cancer without more detail.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include nasal obstruction, epistaxis, ear symptoms, or a neck mass, but you should code only when the malignancy is documented.
When to use this code
Use C11.9 when the record states nasopharyngeal carcinoma, cancer, or malignant neoplasm of the nasopharynx and does not specify a more precise subsite. It also fits when the provider confirms malignancy but leaves the nasopharyngeal location unspecified. If later documentation gives a more specific code, report that instead.
Do not use for
Do not use this code for benign nasopharyngeal lesions, inflammatory disease, or metastatic cancer to the nasopharynx from another primary site. Check documentation if the source or exact diagnosis is unclear.
Coding tip
Query for the exact nasopharyngeal subsite and histology when the note is vague, because a more specific code may apply.