Moles

Definition

A mole (nevus) is a pigmented (colored) spot on the outer layer of the skin (epidermis).

Description

Moles can be round, oval, flat, or raised. They can occur singly or in clusters on any part of the body. Most moles are brown, but colors can range from pinkish flesh tones to yellow, dark blue, or black.

Everyone has at least a few moles. They generally appear by the time a person is 20 and resemble freckles at first. A mole's color and shape don't usually change. Changes in hormone levels that occur during puberty and pregnancy can make moles larger and darker. New moles may also appear during this period.

A mole usually lasts about 50 years before beginning to fade. Some moles disappear completely, and some never lighten at all. Some moles develop stalks that raise them above the skin's surface; these moles eventually drop off.

Types of moles

About 1-3% of all babies have one or more moles when they are born. Moles that are present at birth are called congenital nevi.

Other types of moles include:

• Junctional moles, which are usually brown and may be flat or slightly raised.
• Compound moles, which are slightly raised, range in color from tan to dark brown, and involve pigment-producing cells (melanocytes) in both the upper and lower layers of the skin (epidermis and dermis).
• Dermal moles, which range from flesh-color to brown, are elevated, most common on the upper body, and may contain hairs.
• Sebaceous moles, which are produced by over-active oil glands and are yellow and rough-textured.
• Blue moles, which are slightly raised, colored by pigment deep within the skin, and most common on the head, neck, and arms of women.

Most moles are benign, but atypical moles (dysplastic nevi) may develop into malignant melanoma, a potentially fatal form of skin cancer. Atypical moles are usually hereditary. Most are bigger than a pencil eraser, and the shape and pigmentation are irregular.

Congenital nevi are more apt to become cancerous than moles that develop after birth, especially if they are more than eight inches in diameter. Lentigo maligna (melanotic freckle of Hutchinson), most common on the face and after the age of 50, first appears as a flat spot containing two or more shades of tan. It gradually becomes larger and darker. One in three of these moles develop into a form of skin cancer known as lentigo maligna melanoma.

Causes and symptoms

The cause of moles is unknown, although atypical moles seem to run in families and result from exposure to sunlight.

In the past several years, researchers have identified two genes known as CDKN2A and CDK4 that govern susceptibility to melanoma in humans. Other susceptibility genes are being sought as of early 2003. Most experts, however, think that these susceptibility genes are not sufficient by themselves to account for moles becoming cancerous but are influenced by a combination of other inherited traits and environmental factors.

Diagnosis

Only a small percentage of moles require medical attention. A mole that has the following symptoms should be evaluated by a dermatologist (a physician spealizing in skin diseases).

• Appears after the age of 20
• Bleeds
• Itches
• Looks unusual or changes in any way.

A doctor who suspects skin cancer will remove all or part of the mole for microscopic examination. This procedure, which is usually performed in a doctor's office, is simple, relatively painless, and does not take more than a few minutes. It does leave a scar.

The doctor may also use a dermatoscope to examine the mole prior to removal. The dermatoscope, which can be used to distinguish between benign moles and melanomas, is an instrument that resembles an ophthalmoscope. An immersion oil is first applied to the mole to make the outer layers of skin transparent.

A combination of high-frequency ultrasound and color Doppler studies has also been shown to have a high degree of accuracy in distinguishing between melanomas and benign moles.

Treatment

If laboratory analysis confirms that a mole is cancerous, the dermatologist will remove the rest of the mole. Patients should realize that slicing off a section of a malignant mole will not cause the cancer to spread.

Removing a mole for cosmetic reasons involves numbing the area and using scissors or a scalpel to remove the elevated portion. The patient is left with a flat mole the same color as the original growth. Cutting out parts of the mole above and beneath the surface of the skin can leave a scar more noticeable than the mole.

Scissors or a razor can be used to temporarily remove hair from a mole. Permanent hair removal, however, requires electrolysis or surgical removal of the mole.

Prognosis

Moles are rarely cancerous and, once removed, unlikely to recur. A dermatologist should be consulted if a mole reappears after being removed.

Prevention

Wearing a sunscreen and limiting sun exposure may prevent some moles. Anyone who has moles should examine them every month and see a dermatologist if changes in size, shape, color, or texture occur or if new moles appear.

A team of researchers at Duke University reported in 2003 that topical application of a combination of 15% vitamin C and 1% vitamin E over a four-day period offered significant protection against sunburn. The researchers suggest that this combination may protect skin against aging caused by sunlight as well.

Anyone with a family history of melanoma should see a dermatologist for an annual skin examination. Everyone should know the ABCDEs of melanoma:

• A: Asymmetry, which occurs when the two halves of the mole are not identical
• B: Borders that are irregular or indistinct
• C: Color that varies in a single mole
• D: Diameter, which should be no larger than a pencil eraser (about 6 mm)
• E: Elevated above the surrounding tissue.

KEY TERMS

Dermatology— The branch of medicine that studies and treats disorders of the skin.

Malignant melanoma— A potentially fatal form of skin cancer that develops from melanocytes, which are skin cells containing melanin.

Melanin— A dark insoluble pigment found in humans in the skin, hair, choroid layer of the eye, and a part of the brain called the substantia nigra.

Nevus (plural, nevi)— The medical term for any anomaly of the skin that is present at birth, including moles and birthmarks.

A mole with any of these characteristics should be evaluated by a dermatologist.

Advances in photographic technique have now made it easier to track the development of moles with the help of whole-body photographs. A growing number of hospitals are offering these photographs as part of outpatient mole-monitoring services.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD, editors. "Dermatologic Disorders: Malignant Tumors." Section 10, Chapter 126. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Beers, Mark H., MD, and Robert Berkow, MD, editors. "Dermatologic Disorders: Moles." Section 10, Chapter 125. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Beers, Mark H., MD, and Robert Berkow, MD, editors. "Dermatologic Disorders: Reactions to Sunlight." Section 10, Chapter 119. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

PERIODICALS

Bennett, D. C. "Human Melanocyte Senescence and Melanoma Susceptibility Genes." Oncogene 22 (May 19, 2003): 3063-3069.

Bessoud, B., N. Lassau, S. Koscielny, et al. "High-Frequency Sonography and Color Doppler in the Management of Pigmented Skin Lesions." Ultra sound in Medicine & Biology 6 (June 2003): 875-879.

Bray, C. "The Development of an Improved Method of Photography for Mole-Monitoring at the University Hospital of North Durham." Journal of Audiovisual Media in Medicine 26 (June 2003): 60-66.

Hall, Daniel J., MD, and Michael Holtel, MD. "Malignant Melanoma of the Face and Neck." eMedicine July 3, 2003. 〈http://www.emedecine.com.ent/topic27.htm〉.

Lin, J. Y., M. A. Selim, C. R. Shea, et al. "UV Photoprotection by Combination Topical Antioxidants Vitamin C and Vitamin E." Journal of the American Academy of Dermatology 48 (June 2003): 866-874.

Tucker, M. A., and A. M. Goldstein. "Melanoma Etiology: Where Are We?" Oncogene 22 (May 19, 2003): 3042-3052.

ORGANIZATIONS

American Academy of Dermatology. 930 N. Meacham Road, P.O. Box 4014, Schaumburg, IL 60168-4014. (847) 330-0230. Fax: (847) 330-0050. 〈http://www.aad.org〉.

American Cancer Society. 1599 Clifton Road NE, Atlanta, GA 30329. (800) ACS-2345.

National Cancer Institute (NCI). NCI Public Inquiries Office, Suite 3036A, 6116 Executive Boulevard, MSC8332, Bethesda, MD 20892-8322. (800) 4-CANCER or (800) 332-8615 (TTY). 〈http://www.nci.nih.gov〉.

Nevus Outreach, Inc. 1601 Madison Blvd., Bartesville, OK 74006. (877) 426-3887. 〈http://www.nevus.org〉.

Moles

Definition

A mole (nevus) is a pigmented (colored) spot on the outer layer of the skin (epidermis).

Description

Moles can be round, oval, flat, or raised. They can occur singly or in clusters on any part of the body. Most moles are brown, but colors can range from pinkish flesh tones to yellow, dark blue, or black.

A mole usually lasts about 50 years before beginning to fade. Some moles disappear completely, and some never lighten at all. Some moles develop stalks that raise them above the skin's surface; these moles eventually drop off.

Types of moles

Moles that are present at birth are called congenital nevi.

Other types of moles include:

• junctional moles, which are usually brown and may be flat or slightly raised
• compound moles, which are slightly raised, range in color from tan to dark brown, and involve pigment-producing cells (melanocytes) in both the upper and lower layers of the skin (epidermis and dermis)
• dermal moles, which range from flesh-color to brown, are elevated, most common on the upper body, and may contain hairs
• sebaceous moles, which are produced by over-active oil glands and are yellow and rough-textured
• blue moles, which are slightly raised, colored by pigment deep within the skin, and most common on the head, neck, and arms of women

Most moles are benign (not cancerous), but atypical moles (dysplastic nevi) may develop into malignant melanoma, a potentially fatal form of skin cancer . Atypical moles are usually hereditary. Most are bigger than a pencil eraser, and the shape and pigmentation are irregular.

Congenital nevi are more apt to become cancerous than moles that develop after birth, especially if they are more than eight inches in diameter. Lentigo maligna (melanotic freckle of Hutchinson), most common on the face and after the age of 50, first appears as a flat spot containing two or more shades of tan. It gradually becomes larger and darker. One in three of these moles develop into a form of skin cancer known as lentigo maligna melanoma.

Demographics

Nearly everyone has at least a few moles. They generally appear by the time a person is 20 and at first resemble freckles. A mole's color and shape do not usually change; however, changes in hormone levels that occur during puberty and pregnancy can make moles larger and darker. New moles may also appear during this period. About 1 to 3 percent of all babies have one or more moles when they are born. Only about one in 1 million moles is cancerous.

Causes and symptoms

The cause of moles is unknown, although atypical moles seem to run in families and result from exposure to sunlight. During the early 2000s, researchers identified two genes known as CDKN2A and CDK4 that govern susceptibility to melanoma in humans. Other susceptibility genes are being sought. Most experts, however, think that these susceptibility genes are not sufficient by themselves to account for moles becoming cancerous but are influenced by a combination of other inherited traits and environmental factors.

When to call the doctor

Only a small percentage of moles require medical attention. A mole that has the following symptoms should be evaluated by a dermatologist (a physician specializing in skin diseases):

• bleeds
• itches
• looks unusual or changes in any way

Diagnosis

A doctor who suspects skin cancer will remove all or part of the mole for microscopic examination. This procedure, which is usually performed in a doctor's office, is simple, relatively painless, and does not take more than a few minutes. It does leave a scar.

The doctor may also use a dermatoscope to examine the mole before removal. The dermatoscope, which can be used to distinguish between benign moles and melanomas, is an instrument that resembles an ophthalmoscope used to look at the eye. An oil is first applied to the mole to make the outer layers of skin transparent.

A combination of high-frequency ultrasound and color Doppler studies has also been shown to have a high degree of accuracy in distinguishing between melanomas and benign moles.

Treatment

If laboratory analysis confirms that a mole is cancerous, the dermatologist will remove the rest of the mole. Patients should realize that slicing off a section of a malignant mole will not cause the cancer to spread.

Removing a mole for cosmetic reasons involves numbing the area and using scissors or a scalpel to remove the elevated portion. The patient is left with a flat mole the same color as the original growth. Cutting out parts of the mole above and beneath the surface of the skin can leave a scar more noticeable than the mole.

Scissors or a razor can be used to temporarily remove hair from a mole. Permanent hair removal, however, requires electrolysis or surgical removal of the mole.

Prognosis

Moles are rarely cancerous and, once removed, unlikely to recur. A dermatologist should be consulted if a mole reappears after being removed.

Prevention

Wearing a sunscreen and limiting sun exposure may prevent some moles. Anyone who has moles should examine them every month and see a dermatologist if changes in size, shape, color, or texture occur or if new moles appear.

A team of researchers at Duke University reported in 2003 that topical application of a combination of 15 percent vitamin C and 1 percent vitamin E over a four-day period offered significant protection against sunburn . The researchers suggest that this combination may protect skin against aging caused by sunlight as well.

Anyone with a family history of melanoma should see a dermatologist for an annual skin examination. Everyone should know the ABCDEs of melanoma:

• A: asymmetry, which occurs when the two halves of the mole are not identical
• B: borders that are irregular or indistinct
• C: color that varies in a single mole
• D: diameter, which should be no larger than a pencil eraser (about 6 mm)
• E: elevated above the surrounding tissue

A mole with any of these characteristics should be evaluated by a dermatologist.

Advances in photographic technique had as of 2004 made it easier to track the development of moles with the help of whole-body photographs. A growing number of hospitals are offering these photographs as part of outpatient mole-monitoring services.

Parental concerns

Very few moles are cancerous. Moles on the face or other frequently exposed areas of skin may be troubling for children. If a child is particularly troubled by a mole, a dermatologist can be consulted about its possible removal, although this often leaves a scar.

KEY TERMS

Dermatology —The branch of medicine that studies and treats disorders of the skin.

Malignant melanoma —The most serious of the three types of skin cancer, malignant melanoma arises from the melanocytes, the skin cells that produce the pigment melanin.

Melanin —A pigment that creates hair, skin, and eye color. Melanin also protects the body by absorbing ultraviolet light.

Nevus (plural, nevi) —The medical term for any anomaly of the skin that is present at birth, including moles and birthmarks.

Resources

BOOKS

Crowson, Neil A., et al. The Melanocytic Proliferations: A Comprehensive Textbook of Pigmented Lesions. New York: Wiley-Liss, 2001.

Thompson, June. Spots, Birthmarks, and Rashes: The Complete Guide to Caring for Your Child's Skin. Westport, CT: Firefly Books, 2003.

PERIODICALS

"About Moles, Melanomas, and Lasers: The Dermatologist's Schizophrenic Attitude toward Pigmented Lesions." Archives of Dermatology 139 (November 2003): 1405–7.

Bates, Betsy. "Imaging Devices Assist in Skin Cancer Diagnosis." Family Practice 33 (January 1, 2003): 18.

Chamilin, Sarah L. "Shedding Light on Moles, Melanoma, and the Sun." Contemporary Pediatrics 19 (June, 2002): 102–10.

ORGANIZATIONS

American Academy of Dermatologists. PO Box 4014 Schaumburg, IL 60168–4014. Web site: <www.aad.org>.

Tish Davidson, A.M.
Maureen Haggerty
Rebecca J. Frey, PhD

Moles (Birthmarks)

Birthmarks on the human face or body, usually classed medically as a benign form of nevus. Many superstitions exist about moles, and moleoscopy arose as a system of divination based on the position, character, and astrological connections of these markings. In folk belief, a mole on the throat was said to be a sign of good luck, but unlucky if located on the left side of the forehead near the hair. A mole on the chin, ear, or neck was said to indicate riches, but on the breast to signify poverty.

The position of moles on the various parts of the body had various meanings: On the feet and hands of a woman—many children; on the right arm and shoulder of a man or woman— great lechery; on the ankles or feet—modesty in men and courage in women; on or about the knees—riches and virtue; on a woman's left knee—many children; on the thighs—great poverty and unhappiness. An old folk rhyme from Nottingham-shire, England, indicated the belief that the position of a mole could affect rank in later life:

   "I have a mole above my right eye,
   And shall be a lady before I die."

Another belief was that hairs growing out of moles portended good luck.

During the great witchcraft manias of the sixteenth and seventeenth centuries, such birthmarks as moles, as well as warts, were considered "devil's marks" if they did not bleed when pricked. Professional witch finders like the infamous Matthew Hopkins (died 1647) used pricking on suspected witches. Moles, warts, scars, or other birthmarks were pricked with a long pin; if there was no pain or bleeding, the suspect was claimed to be a witch. Special pricking tools like thin daggers were developed, and some enthusiastic witch prickers (who claimed a substantial fee for each convicted witch) even used trick pricking tools with a hollow shaft and retractable blade, to make sure that the suspect would feel no pain and there would be no bleeding.

Moles (Animal)

Many superstitions grew up around moles. It was a common error to believe that moles were blind, whereas in fact their eyes are small and often hidden in the hair. As late as Shakepeare's time, moles were popularly believed to be blind, as indicated in the dramatist's play The Tempest: "Pray you tread softly, that the blind mole may not hear a footfall."

Other popular beliefs were that if moles came into a meadow it was a sign of fair weather, that if a mole dug his hole very deep, you could expect a very severe winter, and that if a mole threw up earth during a frost, the frost would disappear in two days.

Some Gypsies believed that moles never touched earth that had been stained with blood. In Britain, farm laborers used to wear the forelegs and a hind leg of a mole in a bag around the neck to protect against toothache. It was also believed that if you pulled molehills up on St. Sylvester's Day (December 31), the moles would not throw up earth again.