Malignant neoplasm of external lower lip

This code signifies a primary cancerous tumor originating on the vermilion border or cutaneous portion of the lower lip. It refers to the uncontrolled growth of abnormal cells forming a malignant mass in this specific anatomical location.

Apply this code when documentation clearly indicates a confirmed diagnosis of malignancy affecting the external lower lip. This typically follows a biopsy and pathological confirmation of a primary malignant neoplasm.

• Differentiate from C00.0 (external upper lip) and C00.2 (internal lower lip) based on precise anatomical documentation.
• Ensure the pathology report confirms malignancy and specifies the lower lip as the primary site.
• Do not use for secondary metastatic lesions to the lower lip; use codes from the C79 category for secondary malignancies.