Skin metastases C79.8

cutaneous metastases; metastatic skin cancer; secondary skin cancer; skin metastases; metastatic carcinoma; cutaneous metastases; metastases of the skin; metastatic skin cancer; secondary skin cancer; lymphangiosis carcinomatosa; cancer en cuirasse; 

Lymphogenous or hematogenous metastases of primary skin malignancies or malignant tumors of other organs to the skin. In dermatological practice, metastases of internal malignancies are of differential diagnostic importance. They are rare, occurring in 0.6–10% of patients with metastatic tumors (Gschnell M et al. 2024). 

Their initial manifestation in the skin is often characterized by inconspicuous, painless nodules. A consistently present feature of a cutaneous metastasis is its surprising firmness.

The clinical picture observed in the final stage of tumor progression, featuring diffuse carcinomatosis of the skin, is referred to as lymphangiosis carcinomatosa. When accompanied by an inflammatory tissue reaction, diffusely spreading lymphangiosis carcinomatosa is referred to as erysipelas carcinomatosum. Extensive (usually inflammatory) skin metastasis is referred to as cancer en cuirasse.

In more than 90% of patients, the underlying cancer is already known at the time skin metastases appear.   

Causing primary tumors by decreasing frequency, varied according to Lookingbill et al.

Frequency of cutaneous metastases in men (n=127 patients)

• Tumor type % metastasis
• Malignant melanoma 32%
• Lung 12%
• Colon/rectum 11%
• Oral cavity 8%
• Unknown primary 8%
• Larynx 5%
• Kidneys 5%
• Esophagus 2.4%
• Stomach 1%
• Prostate <1%

Frequency of cutaneous metastases in women (n=420 patients)

• Breast carcinoma 70%
• Malignant melanoma 12%
• Ovarian carcinoma 3.5%
• Unknown primary 3%
• Oral cavity 2.5%
• Lung 2.0%
• Colon/rectum 1.5%
• Endometrium 1.5%
• Urinary bladder 1.5%
• Uterus 0.7%

Causing primary tumors by decreasing frequency:

• Malignant melanoma
• Breast carcinoma
• Gastric carcinoma
• Uterine carcinoma
• Bronchial carcinoma
• Rectal carcinoma
• renal cell carcinoma.

Lymphogenous skin metastases often occur near the primary tumor

Metastases from breast and lung cancers are most commonly found on the anterior side of the thorax.

Pelvic carcinomas tend to metastasize perianally

Gastrointestinal carcinomas, renal cell carcinomas, or ovarian cell carcinomas tend to metastasize to the abdominal skin.

A distinctive feature is umbilical skin metastases in intestinal malignancies (Sister Mary Joseph’s nodule —see below, “Umbilical Metastasis”), which occur by continuity or via the unique vascular supply of the umbilical region. 

The scalp is a preferred site of metastasis for visceral tumors. In men, two-thirds of all skin metastases occur in the head and neck region; in women, one-quarter do. In women, 70% of these metastases originate from metastatic breast cancer; in men, 10% originate from bronchial carcinoma and 10% from tumors of the gastrointestinal tract.

In principle, however, distant metastasis far from the primary site is also possible.

Generally speaking, depending on the location of the metastases, two main clinical presentations can be distinguished, although these may overlap in advanced stages:

• Nodular metastases in the deep dermis and/or subcutaneous tissue (usually resulting from hematogenous spread—differential diagnosis: lipomas, sebaceous cysts)
• Superficial (nodular or plaque-like) metastases located in the upper dermis (usually multiple, usually resulting from lymphogenous spread, usually in the area of the primary tumor). They may have an inflammatory (erysipelas-like) appearance (erysipelas carcinomatosum). In the lymphogenous type of metastasis, skin-colored or red, rapidly growing, broad-based papules or nodules are most common. They tend to grow rapidly (within a few weeks). Their consistency is predominantly “surprisingly” firm. The surface is usually smooth; ulceration is less common.

The erysipelas-like, inflammatory carcinomas (erysipelas carcinomatosum) are characterized by highly inflammatory, bizarrely jagged erythema or plaques (caused by lymphatic carcinoma infiltration). This type of metastasis is found primarily in breast cancer and, less commonly, in tumors of the pancreas, stomach, lung, rectum, and ovary. Similar clinical presentations (usually with black-blue pigmentation) can also occur with locoregional metastasis of malignant melanoma (erysipelas melanomatosum).  

Special morphological and etiological forms of skin metastases are classified under the following clinical terms:

• Erysipelas carcinomatosum
• Erysipelas melanomatosum
• Cancer en cuirasse
• Umbilical metastasis 
• Neoplastic alopecia
• Teleangiectatic carcinoma
• CUP(Cancer of Unknown Primary).

However, in only a few cases can the primary tumor be identified based on the pattern of metastases. Thus, the various designations based solely on macroscopic criteria seem to make little sense. It is not uncommon for skin metastases to occur without any possible association with a primary tumor (CUP = Cancer of unknown primary).

Clusters of cells from an invasively growing tumor located in the dermis and subcutaneous tissue. Characterization of the cells using immunohistochemical methods (use of monoclonal and polyclonal antibodies, e.g., CEA, S100, desmin, cytokeratin, vimentin, and melanoma-associated antibodies).

           Immunohistochemical markers of cutaneous metastases

Breast (ductal carcinoma: CK7, CEA, mammaglobulin, E-cadherin)

Breast (lobular carcinoma: CK7, CEA, EMA, mammaglobulin)

Breast (inflammatory carcinoma (erysipelas carcinomatosa): CD31, podoplanin)

Lung (squamous cell carcinoma: CK5/CK6)

Lung (adenocarcinoma: CK7, CEA, TTF-1, apoprotein A)

Lung (small cell carcinoma: TTF-1, CAM5.2, CK7, CK8/18)

Colorectal (adenocarcinoma: CK20, CEA, CDX2)

Stomach (adenocarcinoma: CK20, CEA, EMA, CDX2)

Kidney (RCC: AE1, AE3, MNF116, CD31,vimentin, CD10, EMA, S100)

Prostate (adenocarcinoma: PSA, AMACR, ERG transcription factor)

Ovaries (ovarian carcinoma: CK7, PAX8, CA.125)

Thyroid (carcinomas: thyroglobulin, TTF-1, PAX8)

Thyroid/medullary (Calcitonin)  

Treatment of the primary tumor, if possible excision of the skin metastases. See below Erysipelas carcinomatosum, Erysipelas melanomatosum and diagnosis-oriented systemic therapy.

Electrochemotherapy: Combination of a cytostatic drug, which is applied intravenously or intratumorally, combined with the application of electrical impulses. The increase in efficacy is 80-fold for cisplatin and up to 8000-fold for bleomycon.

Further local immunotherapies can be carried out with: interleukin 2, imiquimod, miltefosine and DNCB/DCP.

1. Babacan NA et al. (2015) A Case of Multifocal Skin Metastases from Lung Cancer Presenting with a Vasculitis-like Cutaneous Nodule. Indian J Dermatol 60:213
2. Challa VR et al. (2014) Retrospective Study of Marjolin’s Ulcer Over an Eleven-Year Period. J Cutan Aesthet Surg 7:155–19asen.
3. Gschnell M et al. (2024) Cutaneous Metastases: From Epidemiology to Therapy. JDDG 22: 974–991  
4. Kerkhoff L (2026) Lymphangiosis carcinomatosa of the skin in lung carcinoma. Dt Ärzteblatt 123: 280
5. Lookingbill DP et al. (1993) Cutaneous metastases in patients with metastatic carcinoma: a retrospective study of 4,020 patients. J Am Acad Dermatol 29:228–36
6. Nozu S et al. (2022) Lung cancer that recurred as carcinoma en cuirasse. Respirol Case Rep 10:e01041.
7. Siqueira VR et al. (2014) Cutaneous involvement as the initial presentation of metastatic breast adenocarcinoma—Case report. An Bras Dermatol 89:960–963
8. Zhou HY et al. (2014) Cutaneous metastasis from pancreatic cancer: A case report and systematic review of the literature. Oncol Lett 8:2654–2660