Skin cancer can develop anywhere on the body, including in the lower extremities. Skin cancers of the feet have several features in common. Most are painless, and often there is a history of recurrent cracking, bleeding, or ulceration. Frequently, individuals discover their skin cancer after unrelated ailments near the affected site.
The Michigan Podiatric Medical Association (MPMA) asks that you check your feet for signs of skin cancer and visit a podiatrist with any concerns.
While exposure to the sun’s harmful rays is often the cause of skin cancer, cancers of the feet 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. A yearly visit to an MPMA podiatrist is recommended and covered by most insurances.
Podiatrists are uniquely trained as lower extremity specialists to recognize and treat abnormal conditions on the skin of the lower legs and feet. Skin cancers affecting the feet may have a very different appearance from those arising on the rest of the body.
For this reason, a podiatrist’s knowledge and clinical training is of extreme importance for patients for the early detection of both benign and malignant skin tumors. If a lesion is determined to be cancerous, your podiatrist will recommend the best course of treatment for your condition.
Some of the most common cancers of the feet are:
Basal Cell Carcinoma: Basal cell carcinoma frequently is seen on sun-exposed skin surfaces. Basal cell cancers may appear as pearly white bumps or patches that may ooze or crust and look like an open sore. On the skin of the lower legs and feet, basal cell cancers often resemble non-cancerous skin tumors or benign ulcers.
Squamous Cell Carcinoma: Squamous cell carcinoma is the most common form of cancer on the skin of the feet. This form of cancer often begins as a small scaly bump or plaque, which may appear inflamed. Sometimes there is a history of recurrent cracking or bleeding. Occasionally it begins as a hard projecting callus-like lesion.
Though squamous cell cancer is painless, it may be itchy. Squamous cell cancer may resemble a plantar wart, a fungal infection, eczema, an ulcer, or other common skin conditions of the foot.
Malignant Melanoma: Malignant melanoma is one of the deadliest skin cancers known. This type of skin cancer must be detected very early to ensure patient survival. Melanomas may occur on the skin of the feet and, on occasion, beneath a toenail. They are found both on the soles and on the top of the feet.
Malignant melanoma has many potential appearances, leading to its nickname, “The Great Masquerader.” This skin cancer commonly begins as a small brown-black spot or bump; however, roughly one third of cases lack brown pigment and thus appear pink or red.
These tumors may resemble common moles; however, close inspection will usually demonstrate asymmetry, irregular borders, alterations in color, and/or a diameter greater than 6 mm. Melanomas may resemble benign moles, blood blisters, ingrown nails, plantar warts, ulcers caused by poor circulation, foreign bodies, or bruises.
The MPMA suggests that you learn the ABCDs of melanoma. If you notice a mole, bump, or patch on the skin that meets any of the following criteria, see a podiatrist immediately:
Asymmetry – If the lesion is divided in half, the sides don’t match.
Borders – Borders look scalloped, uneven, or ragged.
Color – There may be more than one color. These colors may have an uneven distribution.
Diameter – The lesion is wider than a pencil eraser (greater than 6 mm).
To detect other types of skin cancer, look for spontaneous ulcers and non-healing sores, bumps that crack or bleed, nodules with rolled or “donut-shaped” edges, or scaly areas.
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.