As a podiatric physician/surgeon, I have encountered various lesions that occur on the feet and legs. The vast majority of these lesions are benign; however, some turn out to be malignant melanomas.
Some examples of benign lesions that look like malignant melanomas include nevi (moles) which present as pigmented skin lesions.
Moles can occur as three typical variants: junctional nevi, compound nevi and dermal nevi.
• Junctional moles present as flat, non palpable, hyper pigmented lesions.
• Compound moles are most commonly rounded, raised and hyper pigmented.
• Dermal moles present as round, raised, flesh-colored or pigmented lesions.
Other benign skin lesions that can look like malignant melanoma include plantar wart, corns and callouses, fungus toenails, and diabetic foot ulcers. Some malignant melanomas are pigmented; some are non-pigmented.
Signs of malignant melanoma include changes to the moles or skin lesions. These changes include itchiness, bleeding, changing in color, irregular border, and the lesions growing larger. It is not possible to tell if a skin lesion is benign or malignant by just looking at it. Biopsy of the lesion is the way to find out if a skin lesion is benign or malignant.
The ABCs of malignant melanomas are:
A- Asymmetrical shape of the lesions
B- Bleeding from the lesions
C- Change in color of the lesions
D- Diameter of the lesion is getting larger
The incidence of malignant melanoma has increased over the last few decades. This increase could be attributed to the increase in biopsies performed by physicians as well as an increase of ultraviolet radiation secondary to atmospheric changes.
Melanoma of the feet and legs accounts for approximately 30 to 35 percent of all melanomas of the skin. If physicians diagnose melanoma at the early stage, it is thought to be curable by complete excision. As a melanoma grows and extends deeper into the skin, it becomes more serious and may spread through the body by the lymphatic system and blood vessels. Once a melanoma becomes invasive, survival rates decrease in direct proportion to the thickness of the lesion. Malignant melanoma, can and will result in death if they are inappropriately treated or go undiagnosed; therefore it is important to check the feet and legs, as well as the entire body, for skin lesions.
Given the potentially lethal consequences of malignant melanomas, it is vital to have the lesions biopsied whenever there is doubt. The earlier one detects skin lesions and facilitates an accurate diagnosis, the better the chances are for a good outcome.
-Praya Mam, D.P.M.
Diplomat American Board of Foot & Ankle Surgery
Fellow American College of Foot & Ankle Surgeons