Moles
Moles are growths on the skin. Doctors call moles nevi (one mole is a
nevus).
These growths occur when cells in the skin, called melanocytes,
grow in a cluster with tissue surrounding them. Moles are usually pink,
tan, brown, or flesh-colored. Melanocytes are also spread evenly
throughout the skin and produce the pigment
that gives skin its natural color. When skin is exposed to the sun,
melanocytes produce more pigment, causing the skin to tan, or darken.
Moles are very common. Most people have between 10 and 40 moles. A
person may develop new moles from time to time, usually until about age
40. Moles can be flat or raised. They are usually round or oval and no
larger than a pencil eraser. Many moles begin as a small, flat spot and
slowly become larger in diameter and raised. Over many years, they may
flatten again, become flesh-colored, and go away.
Dysplastic Nevi
About one out of every ten people has at least one unusual (or
atypical) mole that looks different from an ordinary mole. The medical
term for these unusual moles is dysplastic nevi.
Doctors believe that dysplastic nevi are more likely than ordinary
moles to develop into a type of skin cancer called melanoma. Because of
this, moles should be checked regularly by a doctor or nurse specialist,
especially if they look unusual; grow larger; or change in color, outline,
or in any other way.
Melanoma
Melanoma is a type of skin cancer -- one of the most serious types
because advanced melanomas have the ability to spread to other parts of
the body. (Melanoma can also develop in the eye, called intraocular
melanoma, or rarely in other parts of the body where pigment cells are
found. The CIS can provide information about the
diagnosis and treatment of intraocular melanoma.) Melanoma begins when
melanocytes (pigment cells) gradually become more abnormal and divide
without control or order. These cells can invade and destroy the normal
cells around them. The abnormal cells form a growth of malignant
tissue (a cancerous tumor)
on the surface of the skin. Melanoma can begin either in an existing mole
or as a new growth on the skin. The "Pictures
of Melanoma" section shows examples of melanoma. A doctor or nurse
specialist can tell whether an abnormal-looking mole should be closely
watched or should be removed and checked for melanoma cells. The purpose
of routine skin exams is to identify and follow abnormal moles.
The removal of the entire mole or a sample of tissue for examination
under a microscope is called a biopsy.
If possible, it is best to remove moles by an excisional
biopsy, rather than a shave
biopsy.
If the biopsy results in a diagnosis of melanoma, the patient and the
doctor should work together to make treatment decisions. In many cases,
melanoma can be cured by minimal surgery if the tumor is discovered when
it is thin (before it has grown downward from the skin surface) and before
the cancer cells have begun to spread to other places in the body.
However, if melanoma is not found early, the cancer cells can spread
through the bloodstream and lymphatic
system to form tumors in other parts of the body. Melanoma is much
harder to control when it has spread. The spread of cancer is called metastasis.
Doctors and scientists believe that it is possible to prevent many
melanomas and to detect most others early, when the disease is more likely
to be cured with minimal surgery. In the past several decades, an
increasing percentage of melanomas have been diagnosed at very early
stages, when they are quite thin and unlikely to have spread. Learning
about prevention and early detection, while important for everyone, is
especially important for people who have an increased risk for melanoma.
People who are at an increased risk include those who have dysplastic nevi
or a very large number of ordinary moles.
Risk Factors for Melanoma
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Family history of melanoma
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Dysplastic nevi
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History of melanoma
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Weakened immune system
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Many ordinary moles (more than 50)
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Ultraviolet (UV) radiation
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Severe, blistering sunburns
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Freckles
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Fair skin |
It is important to remember that not everyone who has dysplastic nevi
or other risk factors for melanoma gets the disease. In fact, most do not.
Also, about half the people who develop melanoma do not have dysplastic
nevi, and they may not have any other known risk factor for the disease.
At this time, no one can explain why one person gets melanoma while
another does not. Research has shown that sun exposure, especially
excessive exposure that leads to bad, blistering sunburns, is an important
and avoidable risk factor. Scientists are continuing their studies of risk
factors for melanoma.
Prevention of Melanoma
The number of people in the world who develop melanoma is increasing
each year. In the United States, the number has more than doubled in the
past 20 years. Experts believe that much of the worldwide increase in
melanoma is related to an increase in the amount of time people spend in
the sun.
Ultraviolet
(UV) radiation from the sun and from sunlamps and tanning
booths damages the skin and can lead to melanoma and other types of skin
cancer.
Everyone, especially
those who have dysplastic nevi or other risk factors, should try to reduce
the risk of developing melanoma by protecting the skin from UV radiation.
The intensity of UV radiation from the sun is greatest in the summer,
particularly during midday hours. A simple rule is to avoid the sun or
protect your skin whenever your shadow is shorter than you are.
People who work or play in the sun should wear protective clothing,
such as a hat and long sleeves. Also, lotion, cream, or gel that contains
sunscreen
can help protect the skin. Many doctors believe sunscreens may help
prevent melanoma, especially those that reflect, absorb, and/or scatter
both types of ultraviolet radiation. Sunscreens are rated in strength
according to a sun
protection factor (SPF).
The higher the SPF, the more sunburn protection is provided. Sunscreens
with an SPF value of 2 to 11 provide minimal protection against sunburns.
Sunscreens with an SPF of 12 to 29 provide moderate protection. Those with
an SPF of 30 or higher provide high protection against sunburn. Sunglasses
that have UV-absorbing lenses should also be worn. The label should
specify that the lenses block at least 99 percent of UVA and UVB
radiation.
Early Detection of Melanoma
Because melanoma usually begins on the surface of the skin, it often
can be detected at an early stage with a total skin examination by a
trained health care worker. Checking the skin regularly for any signs of
the disease increases the chance of finding melanoma early. A monthly skin
self-exam is very important for people who have any of the known risk
factors, but doing skin self-exams routinely is a good idea for
everyone.
Here is how to do a skin self-exam:
-
After a bath or shower, stand in front of a full-length mirror in a
well-lighted room. Use a hand-held mirror to look at hard-to-see
areas.
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Begin with the face and scalp and work downward, checking the head,
neck, shoulders, back, chest, and so on. Be sure to check the front,
back, and sides of the arms and legs. Also, check the groin, the palms,
the fingernails, the soles of the feet, the toenails, and the area
between the toes.
-
Be sure to check the hard-to-see areas of the body, such as the scalp
and neck. A friend or relative may be able to help inspect these areas.
Use a comb or a blow dryer to help move hair so you can see the scalp
and neck better.
-
Be aware of where your moles are and how they look. By checking your
skin regularly, you will become familiar with what your moles look like.
Look for any signs of change, particularly a new black mole or a
change in outline, shape, size, color (especially a new black area), or
feel of an existing mole. Also, note any new, unusual, or "ugly-looking"
moles. If your doctor has taken photos of your skin, compare these
pictures with the way your skin looks on self-examination.
-
Check moles carefully during times of hormone changes, such as
adolescence, pregnancy, and menopause. As hormone levels change, moles
may change.
-
It may be helpful to record the dates of your skin exams and to write
notes about the way your skin looks. If you find anything unusual, see
your doctor right away. Remember, the earlier a melanoma is found, the
better the chance for a cure.
In addition to doing routine skin self-exams, people should have their
skin checked regularly by a doctor or nurse specialist. A doctor can do a
skin exam during visits for regular checkups. People who think they have
dysplastic nevi should point them out to the doctor. It is also important
to tell the doctor about any new, changing, or "ugly-looking" moles.
Sometimes it is necessary to see a specialist. A dermatologist
(skin doctor) is likely to have the most training in diseases of the skin.
Some plastic surgeons, general surgeons, oncologists,
internists, and family doctors also have a special interest and training
in moles and melanoma.
Melanoma may run in families, and members of these families are at high
risk for the disease. In some of these families, certain members also have
a large number (usually over 100) of dysplastic
nevi. These people have an especially high risk of developing
melanoma. When two or more family members develop melanoma, it is
important for all of the patients' close relatives (parents, brothers,
sisters, and children above the age of 10) to see a doctor and be examined
carefully for dysplastic nevi or any signs of melanoma. The doctor can
then decide how often each person needs to be seen. (Doctors may recommend
that these family members have checkups every 6 months.) Anyone who has a
large number of dysplastic nevi also should be examined regularly.
A doctor may want to watch a slightly abnormal mole closely to see
whether it changes over time. Pictures taken at one visit may be compared
with the appearance of the mole at the next visit. Sometimes a doctor
decides that a mole should be removed so that the tissue can be examined
under a microscope. The removal of a mole, called a biopsy, is usually
done in the doctor's office using a local anesthetic.
It generally takes only a few minutes. The patient may require stitches,
and a small scar will remain after healing. A pathologist
examines the tissue under a microscope to see whether the melanocytes are
normal, dysplastic, or cancerous.
Because most moles, including most dysplastic nevi, do not develop into
melanoma, removing all of them is not necessary. A doctor can recommend
when and when not to remove moles. Usually, only moles that look like
melanoma, those that change, or those that are both new and look abnormal
need to be removed.
Keeping on Top of Your Condition
Keeping in tune with your disease or condition not only makes treatment less intimidating but also increases its chance of success, and has been shown to lower a patients risk of complications. As well, as an informed patient, you are better able to discuss your condition and treatment options with your physician.
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