Skin Cancer, Melanoma

Early signs

The most important warning sign for melanoma is any change in size, shape, or color of a mole or other skin growth, such as a birthmark. Watch for changes that occur over a period of weeks to a month. Use the American Cancer Society's ABCD rule to evaluate skin changes, and call your health professional if you have any of the following changes.⁴

• A is for asymmetry. One half of the mole or skin growth doesn't match the other half.
• B is for border irregularity. The edges are ragged, notched, or blurred.
• C is for color. The pigmentation is not uniform. Shades of tan, brown, and black are present. Dashes of red, white, and blue add to the mottled appearance. Changes in color distribution, especially the spread of color from the edge of a mole into the surrounding skin, also are an early sign of melanoma.
• D is for diameter. The mole or skin growth is larger than 6 mm (0.2 in.) or about the size of a pencil eraser. Any growth of a mole should be of concern.

Signs of melanoma in an existing mole include changes in:

• Elevation, such as thickening or raising of a previously flat mole.
• Surface, such as scaling, erosion, oozing, bleeding, or crusting.
• Surrounding skin, such as redness, swelling, or small new patches of color around a larger lesion (satellite pigmentations).
• Sensation, such as itching, tingling, or burning.
• Consistency, such as softening or small pieces that break off easily (friability).

Melanoma can develop in an existing mole or other mark on the skin, but it often develops in unmarked skin. Although melanoma can grow anywhere on the body, it frequently occurs on the upper back of men and women and on the legs in women. Less commonly, it can develop on the soles, palms, nail beds, or mucous membranes that line body cavities such as the mouth, the rectum, and the vagina.⁵

Many other skin conditions (such as seborrheic keratosis, warts, and basal cell cancer) have features similar to those of melanoma.

Later symptoms

Later signs of melanoma include:

• A break in the skin or bleeding from a mole or other colored skin lesion.
• Pain in a mole or lesion.

Symptoms of metastatic melanoma may be vague and include:

• Swollen lymph nodes, especially in the armpit or groin.
• A colorless lump or thickening under the skin.
• Unexplained weight loss.
• Gray skin (melanosis).
• Ongoing (chronic) cough.
• Headaches.
• Seizures.