Malignant neoplasm of overlapping sites of lip

This code signifies a cancerous tumor that spans across multiple sub-sites of the lip, making it impossible to assign to a single, specific lip region. This typically involves the vermilion border, inner surface, or commissures, where the malignancy extends beyond a single anatomical boundary.

Apply this code when documentation clearly indicates a primary malignant neoplasm affecting contiguous or overlapping areas of the lip. This is appropriate when the tumor's origin cannot be localized to a single, distinct part of the lip (e.g., upper lip, lower lip, commissure). Supporting documentation should explicitly describe the tumor's multi-site involvement.

• Do not use this code if the malignancy is clearly confined to a single sub-site of the lip; instead, use the more specific code for that site.
• Ensure the medical record explicitly states "overlapping sites" or describes the tumor's extension across multiple lip regions.
• Always sequence this code as the primary diagnosis if it represents the reason for the encounter, followed by any relevant secondary diagnoses.