Melanoma of the Foot & Ankle
We often view the sun’s harmful rays as the primary cause of skin cancer; the condition is often found on parts of the body that receive the most sun exposure. Skin cancers of the feet, however, are more often related to viruses, exposure to chemicals, chronic inflammation or irritation, or inherited traits. Unfortunately, the skin of the feet is often overlooked during routine medical examinations, and for this reason, it important that the feet are checked regularly for abnormalities that might indicate evolving skin cancer.
Melanoma that occurs in the foot or ankle often goes unnoticed during its earliest stage, when it would be more easily treated. By the time melanoma of the foot or ankle is diagnosed, it frequently has progressed to an advanced stage, accounting for a higher mortality rate. This makes it extremely important to follow prevention and early detection measures involving the feet as well as other parts of the body.
There is a relationship between ultraviolet (UV) exposure and the development of melanoma on sun-exposed areas. Data have demonstrated that irregular and intense exposure to sunlight significantly increases the risk of melanoma.4 However, the role of UV light on non-exposed areas such as the sole of the foot is unclear, the cause may be linked to viruses, exposure to chemicals, chronic inflammation or irritation or inherited traits.
If the lesion is thought to be a melanoma, the doctor will take a skin sample from the suspicious area to look at more closely under a microscope. This is called a skin biopsy. Different methods can be used for a skin biopsy depending on the size of the affected area and other factors. A local anesthetic (numbing medicine) will be injected into the area with a very small needle. It is likely you will feel a small prick and a little stinging as the medicine is injected, but you should not feel any pain during the biopsy. The biopsy will remove as much as the area in question as possible to gain an accurate diagnosis.
Often, the first sign of melanoma is a change in the size, shape, color, or feel of an existing mole. Most melanomas have a black or blue-black area. Melanoma also may appear as a new mole. It may be black, abnormal, or “ugly looking.” Thinking of “ABCD” can help you remember what to watch for:
- Asymmetry — The shape of one half does not match the other.
- Border — The edges are often ragged, notched, blurred, or irregular in outline; the pigment may spread into the surrounding skin.
- Color — The color is uneven. Shades of black, brown, and tan may be present. Areas of white, grey, red, pink, or blue also may be seen.
- Diameter — There is a change in size, usually an increase. Melanomas are usually larger than the eraser of a pencil (1/4 inch or 5 millimeters).
Melanoma can be cured if it is diagnosed and treated when the tumor is thin and has not deeply invaded the skin. However, if a melanoma is not removed at its early stages, cancer cells may grow downward from the skin surface and invade healthy tissue. When a melanoma becomes thick and deep, the disease often spreads to other parts of the body and is difficult to control. People who have had melanoma have a high risk of developing a new melanoma. People at risk for any reason should check their skin regularly and have regular skin exams by a health care provider. Prevention of skin cancer on the feet and ankles is similar to any other body part. Limit sun exposure, and make sure to apply appropriate sunscreen when you are outdoors and your feet and ankles are exposed.