ICD-10 Code C10.4 – Malignant neoplasm of branchial cleft (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C10.4 – Malignant neoplasm of branchial cleft
What it is
C10.4 identifies a malignant tumor arising in the branchial cleft region of the oropharynx. Use it when the documentation specifies cancer in this anatomic site.
Clinical signs
Clinical features vary; refer to documentation. Patients may present with a visible or palpable mass, throat discomfort, dysphagia, or related head and neck findings confirmed by exam or biopsy.
When to use this code
Use C10.4 when the provider documents malignant neoplasm of the branchial cleft, branchial cleft cancer, or a primary tumor in that site. Code it from confirmed pathology, imaging, or specialist assessment when the location is clearly stated.
If the record only says “neck mass” or “branchial cleft cyst” without malignancy, you should not assign this code. Check documentation for the exact anatomic site and whether the lesion is primary or metastatic.
Do not use for
Do not use C10.4 for benign branchial cleft cysts, unspecified oral cavity cancers, or metastatic disease to the area. Check documentation if the primary site is elsewhere.
Coding tip
Verify that “branchial cleft” is documented as the malignant site, not just part of a differential diagnosis.