Brenda Spriggs, MD, MPH, MBA
Both melanoma and age spots can cause brown lesions on the skin. It is important to be able to tell the difference between the two: while age spots can be a nuisance, melanoma can be deadly; in fact, it's the most dangerous form of skin cancer. Although melanoma and age spots share common features, there are ways to distinguish them.
Based on data from the American Cancer Society, melanoma causes less than 5 percent of skin cancers but is responsible for the most skin cancer-related deaths. Melanoma occurs when the pigment cells, or melanocytes, in the skin become cancerous. Skin lesions due to melanoma may be raised or flat and are often dark brown or black. Lesions that are asymmetrical, have irregular edges and contain whitish or reddish areas of discoloration are typical of melanoma. Additionally, melanoma lesions tend to be larger than 6 mm -- about the size of a pencil eraser -- and often change in shape and color over time.
Age spots, also known as liver spots or solar lentigines, are linked to aging and sun exposure. These benign, pigmented patches form on sun-exposed areas of the skin, such as the face, backs of the hands and forearms. The lesions are typically oval, flat and may be brown, black or gray. Unlike lesions due to melanoma, age spots are usually uniform in color, have smooth borders and remain stable in appearance. When age spots develop, they do not cause symptoms, whereas melanoma lesions may be painful, itchy and prone to bleeding.
People who have a history of heavy sun exposure are at increased risk for both melanoma and age spots. To prevent sun-related skin damage, the American Academy of Dermatology advises daily use of sunscreen with an SPF of 30 or higher, even on days that are cloudy or overcast. Be sure to choose a sunscreen that also provides specific protection against damaging ultraviolet rays from the sun, known as UVA and UVB rays. Minimizing time outside when the sun is most powerful, between 10 am and 2 pm, is recommended as well.
Age spots do not require treatment, although it's possible to treat them cosmetically with bleaching creams or laser treatments. If melanoma is diagnosed before it has spread to other organs, it is highly curable. Melanoma must be surgically removed. Depending on the size of the lesion, melanoma can sometimes be removed in your dermatologist's office. If melanoma has invaded deep into the skin or spread to other organs, chemotherapy or radiation therapy may be necessary. If you notice a mole or area on your skin that looks unusual or has changed in appearance, be sure to let your doctor know. Early diagnosis and treatment can be life-saving.