How to Spot the Warning Signs of Hidden Melanomas
The last place one might look for melanoma, the most serious form of skin cancer, is exactly the place where a small percentage shows up " such as under the nails, on the scalp, palms of the hands and soles of the feet. Since they are not easily detected and symptoms can mimic other conditions, these skin cancers are very dangerous. If left undetected, hidden melanomas can pose a serious threat to a person's health and prognosis.
"People need to know that melanoma is not limited to sun-exposed areas of the body," said dermatologist Stephen P. Stone, M.D., president of the American Academy of Dermatology (Academy). "That's why the Academy is advising everyone to conduct regular self-examinations and be aware of the areas of the body where melanoma can hide."
Melanoma that manifests itself within the nail plate, which is known as subungal melanoma, accounts for a fraction of all skin cancer cases " 2 percent in Caucasians and 30 percent to 40 percent in people with skin of color. While these melanomas most commonly occur under the nail of the thumb or big toe, they are often characterized by the appearance of a brown- or black-colored streak within the nail plate that is often mistaken for a bruise caused by an injury to the nail.
In a study entitled, "Melanotic macule of nail unit and its clinicopathologic spectrum," published in the April 2006 issue of the Journal of the American Academy of Dermatology, dermatologist Richard K. Scher, M.D., professor of clinical dermatology at Columbia University in New York City, and his group found that the clinical appearance of the pigmented band within the nail plate was not an accurate predictor of the underlying medical cause of the condition.
"This study underscores the importance of obtaining a biopsy of the nail matrix in order to accurately diagnosis subungal melanoma," explained Dr. Scher. "Patients should see a dermatologist if a dark-colored streak appears within the nail plate, if the nail discoloration does not gradually improve or if the size of the streak increases over time."
Melanoma that occurs on the scalp also is difficult to detect, as it is easily hidden by hair. Since symptoms do not usually appear until the melanoma has progressed to an advanced stage, dermatologists recommend that everyone examines the scalp during a self-exam - using a blow dryer to part the hair away from the scalp and a mirror for hard-to-see areas.
Symptoms of melanoma occurring on the scalp include a pigmented lesion that has recently appeared or changed or a lesion that bleeds. To determine if whether or not a mole is suspicious, it is helpful to keep in mind the ABCDs of melanoma:
* Asymmetry " meaning one half of a mole is different than another;
* Border Irregularity " the edge, or border, of melanomas are usually ragged, notched or blurred;
* Color " benign moles can be any color, but a single mole will be only one color. Melanoma often has a variety of hues and colors within the same lesion; and
* Diameter " while melanomas are usually greater than 6 mm (a pencil eraser) in diameter when diagnosed, they can be smaller. If a mole is different from others, or it changes, itches or bleeds, even if it is smaller than 6 mm, see a dermatologist.
Melanoma also can occur in other unusual areas, such as in the eyes, on the palms of the hands or the soles of the feet, or the mucosal tissue lining the nose, mouth, genitalia, anus, urinary tract and esophagus.
"With these types of hidden melanomas, symptoms often include bleeding, pain or an unusual sensation without a known cause," said Dr. Stone. "It's extremely important to seek the proper medical attention for problems that arise in these areas to rule out melanoma or another serious medical condition."
To raise awareness about the importance of skin cancer screenings, nearly 2,000 dermatologists provide free skin cancer screenings across the country as part of the Academy's National Skin Cancer Screening Program. On Saturday, May 6, 2006, the Academy will attempt to set a Guinness World Record for the most people screened for skin cancer in a single day.
It is estimated that there will be about 111,900 new cases of melanoma diagnosed in 2006, representing a more than 9 percent increase in new cases of melanoma since 2005. This year alone, nearly 8,000 deaths will be attributed to melanoma, yet when detected early, skin cancer has a 95 percent cure rate. "The earlier you detect skin cancer, the better your chances of complete cure," said Dr. Stone. "That's why we recommend everyone conduct self-examinations and see a dermatologist if you find something suspicious."
By The American Academy of Dermatology
This page is updated on May 11, 2013.