A cutaneous metastases often signify the recurrence of a cancer thought to be cured. It is essentially a tumor that has traveled to and grows on the skin. The cancers most likely to spread to the skin are breast, stomach, lung, uterus, large intestine, and kidneys.
Cancers that have the highest propensity to metastasize to the skin include melanoma (45% of cutaneous metastasis cases) and cancers of the breast (30%), nasal sinuses (20%), larynx (16%), and oral cavity (12%). Because breast cancer is so common, cutaneous metastasis of breast cancer is the most frequently encountered type of cutaneous metastasis.
It is also possible for some internal cancers to announce themselves via a skin rash. This is called cutaneous paraneoplastic syndrome and it is relatively uncommon. However, it’s very important to recognize this possibility. Considering this can lead to a quicker diagnosis and treatment.
Cutaneous paraneoplastic syndrome
Skin changes can often be the first sign of a deeper problem including an internal malignancy. Signs of skin disease may precede, occur with, or follow the detection of an associated cancer. These skin findings can be a feature of an undiagnosed cancer or provide the clue to a genetic syndrome which has an increased risk of certain cancers and may be the prompt for a thorough examination in patients. Or in a patient whose cancer is in remission, these skin diseases may be the initial sign of the cancer recurring.
Cutaneous signs of other cancers can be classified into 2 major types:
Genetically determined syndromes with a cutaneous component (genodermatoses) that predispose at risk individuals to develop cancer
Paraneoplastic syndromes which occur around the same time an underlying cancer is discovered
Skin findings in cutaneous paraneoplastic syndromes are a broad group of different findings that may be associated with an internal malignancy. Some examples of these are acanthosis nigricans, tripe palms, dermatitis herpetiformis, dermatomyositis, extramammary Paget's disease, hypertrophic pulmonary osteoarthropathy, paraneoplastic pemphigus, intractable itching, pyoderma gangrenosum, Sweet's syndrome and reactive erythemas.
If a paraneoplastic skin condition is suspected, an appropriate work-up, including an age-appropriate cancer screen, should be pursued to search for an underlying cause in a patient without known cancer or to detect recurrent or metastatic disease in a patient with an established history of malignancy. The staff at the Dermatological Center for Skin Health work together as a team to ensure the most efficient and seamless effort to determine if there is any cause for concern.