Images of Nevus, Common Acquired (Mole, Nevus)
A nevus is commonly called a mole; moles can be noncancerous (benign) or cancerous (malignant), present at birth (congenital) or develop after birth (acquired). Some moles are raised and some are flat, and they can range in color from skin-colored to pink, tan, brown, black, or even blue. Regardless of these differences, all moles are made up of collections of the pigment-producing cells of the skin. It is very difficult to look at a mole and know if it is cancerous or not. Some signs of malignancy include large size (bigger than a pencil eraser), rapid growth or change, multiple colors in one mole, or unusual shape. You should show any mole that you are concerned about to your doctor.
Who's at risk?
Moles can occur in people of all races but are more common and more noticeable in lighter-skinned individuals. Most acquired moles develop between the ages of 10 and 30. A family predisposition to moles and exposure to sun and tanning beds all increase the risk of developing more moles.
Signs and Symptoms
- Moles may occur anywhere on the body, including the nails, palms, and soles.
- Moles may be raised or flat.
- Color may vary from pink to brown; they may be darker in people with normally darker skin.
- Noncancerous (benign) moles are usually alike on both sides (symmetrical), have smooth borders and regular color, and are generally smaller than the size of a pencil eraser (6 mm).
- Protective measures, such as avoiding skin exposure to sunlight during peak sun hours (10 AM to 3 PM), wearing protective clothing, and applying high-SPF sunscreen, are essential for reducing exposure to harmful ultraviolet (UV) light.
- Monthly self-examination of the skin is helpful to detect new lesions or changes in existing lesions.
- Be sure your moles are not signs of skin cancer (melanoma). Remember the ABCDEs of melanoma lesions:
A - Asymmetry: One half of the lesion does not mirror the other half.
B - Border: The borders are irregular or vague (indistinct).
C - Color: More than one color may be noted within the mole.
D - Diameter: Size greater than 6 mm (roughly the size of a pencil eraser) may be concerning.
E - Evolving: Notable changes in the lesion over time are suspicious signs for skin cancer.
When to Seek Medical Care
- The occurrence of a new mole in an adult over the age of 50 years is unusual; if it occurs, see your doctor for evaluation.
- People with multiple moles and unusual (atypical) moles should be examined by a dermatologist every 4–12 months depending on their past history and family history.
- It may be difficult to tell an atypical mole from a normal mole, so seek medical evaluation if you are unsure about the nature of a mole, if you note changes within a mole, or if a mole becomes irritated or painful.
Treatments Your Physician May Prescribe
- Noncancerous (benign) moles do not require treatment, though they may be cosmetically removed.
- If benign-appearing moles are inflamed or irritated, they can be surgically removed.
Trusted LinksClinical Information and Differential Diagnosis of Nevus, Common Acquired (Mole, Nevus)
eedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.889-893. New York: McGraw-Hill, 2003.