C79.2

Billable

Secondary malignant neoplasm of skin

HCC Category Mapping

V28HCC 18 — Metastatic Cancer to Peritoneum and Other Specified Sites

0.368

V24HCC 10 — Lymphoma and Other Cancers

0.675

ESRDHCC 10 — Lymphoma and Other Cancers

0.000

RxHCCHCC 18 — Metastatic Cancer to Lung and Other Respiratory Sites

0.000

What This Code Means

Cancer that has spread to the skin from a primary cancer in another part of the body.

Coding Tips

•Document the specific anatomical location of the skin lesion if possible, as this may affect treatment planning and prognosis
•Ensure the primary cancer site is coded separately to provide complete clinical picture of metastatic disease

Clinical Significance

Secondary malignant neoplasm of skin indicates metastatic cancer has spread to the skin from an internal primary cancer. Cutaneous metastases are relatively uncommon but carry significant prognostic implications, often indicating widely disseminated disease. The most common primary cancers that metastasize to skin include breast, lung, colorectal, and melanoma.

Documentation Requirements

✓Primary cancer site documented and coded separately
✓Anatomical location of the cutaneous metastasis
✓Biopsy confirmation distinguishing metastatic deposits from primary skin cancers
✓Number and distribution of skin lesions
✓Clinical description — nodular, inflammatory, or ulcerating presentation

Excludes 1 — Do NOT code together

secondary Merkel cell carcinoma (C7B.1)

Commonly Confused Codes

C43.0-C43.9 — Primary malignant melanoma of skin; melanoma is a primary skin cancer, not metastatic from another site C44.0-C44.99 — Other primary malignant neoplasms of skin; basal cell and squamous cell carcinomas are primary, not secondary C79.89 — Secondary malignant neoplasm of other specified sites; skin metastases have their own specific code C79.2 D03.0-D03.9 — Melanoma in situ; this is a pre-invasive primary lesion, not metastatic disease

Code Hierarchy

└C79Secondary malignant neoplasm of other and unspecified sites └C79.2Secondary malignant neoplasm of skin

└C79.2Secondary malignant neoplasm of skin