Some types of skin moles can increase your chance of developing melanoma, a potentially deadly type of skin cancer. Melanoma is diagnosed in approximately 40,000 Americans each year, according to the American Osteopathic College of Dermatology. Recognizing the signs of dangerous skin moles and obtaining prompt treatment for cancerous moles are important steps in maintaining your good health.
Identification
Moles can develop after birth or can be present at birth in the case of congenital moles. Moles form when skin pigment cells, called melanocytes, grow in a cluster with tissue surrounding them, according to the National Cancer Institute. Most moles are harmless skin growths that never cause any health problems.
Dangerous Moles
Large or giant congenital moles that are greater than 20 cm have been shown to carry a higher risk of developing a melanoma, according to the American Academy of Dermatology.
Atypical moles, also called dysplastic nevi, are not perfectly round like other moles and may have irregular borders, color variations or be larger than a pencil eraser. Atypical moles can become cancerous, but not everyone who has an atypical mole develops cancer, according to the American Osteopathic College of Dermatology. Potentially dangerous moles may change in appearance or may itch or bleed.
Risk Factors
The presence of one atypical mole raises your risk of developing cancer two times, while the presence of 10 or more abnormal moles raises your cancer risk 14 times, according to the American Osteopathic College of Dermatology. If a family member developed melanoma from an atypical mole, you may be more likely to develop the disease if you also have atypical moles.
Diagnosis
If your doctor thinks your mole may be cancerous, he will perform a skin biopsy or completely remove the mole. During a biopsy, your doctor removes only a small part of the mole. After the biopsy or removal, the entire mole or mole sample is sent to a laboratory for testing. A biopsy is the only way to determine if a mole is cancerous, according to the American Academy of Dermatology.
Treatment
If the mole is found to be cancerous and hasn't already been removed, your doctor will remove the mole and an area of healthy skin surrounding the mole. The amount of healthy skin removed varies depending on the stage of the cancer. Your doctor may also perform a lymph node biopsy to determine if melanoma may have spread to other parts of your body and may order tests, such as chest X-rays or magnetic resonance imaging scans, to search for cancer in other parts of your body.
Doctors use chemotherapy, radiation therapy or gene therapy to treat melanoma. The University of Texas MD Anderson Cancer Center reports that additional treatment beyond removal of the mole and surrounding tissue is usually unnecessary if the melanoma is less than 1 mm thick.
