Malignant neoplasm of commissure of lip, unspecified

This code represents a cancerous tumor originating at the labial commissure, which is the corner or angle of the mouth where the upper and lower lips meet. This malignancy is of an unspecified nature regarding its specific histological type or behavior, and its exact location within the commissure is not further detailed.

Use this code when documentation clearly indicates a malignant neoplasm located at the commissure of the lip, and no further specificity regarding the exact subsite (e.g., right, left) or histological type is provided. This code is appropriate when the physician's diagnosis explicitly states "malignant neoplasm of commissure of lip, unspecified."

• Ensure the documentation specifies "commissure of lip" and not merely "lip" to avoid miscoding to a more general lip site.
• If laterality (right or left) is documented, a more specific code within the C00 series should be used.
• Always review pathology reports when available, as they often provide the specific histological type, which would necessitate a more precise code.