Podiatrists are uniquely trained as lower extremity specialists to recognize and treat abnormal conditions as they present themselves on the skin of the lower legs and feet. Skin cancers in the lower extremity 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.
Your podiatrist will investigate the possibility of skin cancer both through his/her clinical examination and with the use of a skin biopsy. A skin biopsy is a simple procedure in which a small sample of the skin lesion is obtained and sent to a specialized laboratory where a skin pathologist will examine the tissue in greater detail. To ensure that you will receive the very best in care, your podiatrist will likely require that your skin biopsy be sent to a lab with board-certified dermapathologists who have specialized training in the analysis of abnormal skin lesions from the lower leg and foot. If a lesion is determined to be malignant, your podiatrist will recommend the best course of treatment for your condition.
Common Types of Skin Cancers of the Feet
Basal Cell Carcinoma
Basal cell carcinoma is frequently seen on sun-exposed skin surfaces. With feet being significantly less exposed to the sun, it occurs there less often. This form of skin cancer is one of the least aggressive cancers in the body. It will cause local damage, but only rarely spreads beyond the skin. Basal cell cancers may appear as pearly white bumps or patches which may ooze or crust similar in appearance to 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. Most types of early squamous cell carcinomas are confined to the skin and do not spread. However, when advanced, some can become more aggressive and spread throughout the body. 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 they begin 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 dermatological conditions of the foot.
Malignant melanoma is one of the deadliest skin cancers known. Nonsurgical treatments are rarely effective and many remain experimental. 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 tops of the feet. As a melanoma grows and extends deeper into the skin, it becomes more serious and may spread through the body through the lymphatics and blood vesels.
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 will lack brown pigment and thus appear red or pink. These tumors may resemble common moles; however, close inspection will usually demonstrate asymmetry, irregular borders, alterations in color, and/or a diameter of greater than 6mm. Melanomas may resemble benign moles, blood blisters, ingrown nails, plantar warts, ulcers caused by poor circulation, foreign bodies, or bruises.