Moles, known medically as
nevi, are clusters of pigmented cells that often
appear as small, dark brown spots on your torso,
face, arms and legs. But moles can come in a range
of colors and can develop virtually anywhere,
including your scalp, armpits, under your nails, and
between your fingers and toes.
Most people have between 10
and 40 moles, although the number you have may
change throughout life. New moles can appear into
mid-adulthood, and because moles last about 50
years, some moles may disappear as you age. The great
majority of moles are harmless, but in rare cases,
moles may become cancerous. Monitoring moles and
other pigmented patches is an important step in the
diagnosis of skin cancer, especially malignant
melanoma. Although not all melanomas develop from
pre-existing moles, many begin in or near a mole or
other dark spot on the skin.
The best way to catch
potential problems at an early stage is to become
familiar with the location and pattern of your
moles. Examine your skin carefully on a regular
basis — monthly if you have a family history of
melanoma, and at least every three months otherwise
— to detect early skin changes that may signal
melanoma.
Remember to check areas that aren't exposed to
sunlight, including your scalp, armpits, feet (the
soles and between the toes), genital area and, if
you're a woman, the skin underneath your breasts. If
necessary, use a hand-held mirror along with a wall
mirror to scan hard-to-see places such as your back.
People with dysplastic nevi are at greater risk of
developing malignant melanoma and may want to
consider having a dermatologist check their moles on
a regular basis.
To detect melanomas or
other skin cancers, use the A-B-C-D skin
self-examination guide, adapted from the American
Academy of Dermatology:
A is for asymmetrical shape.
Look for moles with irregular shapes, such as
two very different-looking halves.
B is for irregular border.
Look for moles with irregular, notched or
scalloped borders — the characteristics of
melanomas.
C is for changes in color.
Look for growths that have many colors or an
uneven distribution of color.
D is for diameter. Look for
growths that are larger than about 1/4 inch (6
millimeters).