Secondary malignant neoplasm of skin

This code signifies the presence of a cancerous tumor that has spread to the skin from a primary cancer site elsewhere in the body. It indicates metastatic disease affecting the integumentary system, not a primary skin cancer.

Use this code when documentation clearly states "metastatic carcinoma to skin," "secondary malignant neoplasm of skin," or similar phrasing, indicating the skin is a site of metastasis. This code is appropriate when the primary malignancy has been identified or is still being investigated.

• Always sequence the primary malignancy code before this secondary site code, unless the primary is unknown or has been excised and is no longer being treated.
• Distinguish carefully from primary skin cancers (e.g., melanoma, basal cell carcinoma, squamous cell carcinoma), which are coded differently.
• Ensure the medical record explicitly states the skin lesion is a metastasis, not a new primary or benign lesion.