Nevi (Moles)
Nevi is the medical term for moles, beauty marks and birthmarks. Nevi are common noncancerous skin lesions comprised of a cluster of melanocytes, the cells that give the skin its color. A nevus is a single mole or pigmented lesion.
Most nevi are brown or tan and develop in childhood, but nevi can change with age, including changing color, size, and shape. Many adults have 10-40 moles. The majority of moles are harmless. However, people with 10 or more moles are at greater risk of developing melanoma.
Types of moles
Congenital moles
Congenital moles are present at birth and include birth marks. While most are harmless, extremely large congenital moles on occasion can develop into melanoma, the deadliest type of skin cancer. For example, according to the American Cancer Society, the risk for melanoma is very low in congenital nevi smaller than the palm of the hand, while those that cover large portions of back and buttocks (“bathing trunk nevi”) have significantly higher risks.
Common moles
Common moles are usually round or oval, raised or flat, and contain a single color, usually brown, tan, or skin colored. They have well defined-borders and are smaller than 1/4 inch in size. Fair skinned individuals tend to develop more common moles than people of color.
Dysplastic moles
Dysplastic moles are nevi with abnormally shaped cells or cells that are abnormally dividing (dysplasia). It is a diagnosis that must be made under the microscope. Dysplastic nevi are typically larger than a regular mole, and often contain various colors or a dark brown center. They can appear flat and smooth, or raised and scaly with uneven edges. Dysplastic moles are graded as mild, moderate or severe depending upon the degree to which the cells appear abnormal under the microscope. Therefore, an irregular mole should be biopsied to determine:
- Is it melanoma?
- If not a melanoma, is it a dysplastic mole?
- If it is a dysplastic nevus, is the degree of abnormality mild, moderate or severe?
While dysplastic moles are not melanoma, they can increase the risk of developing melanoma, especially if the mole is severely dysplastic. People with dysplastic moles and a family member with melanoma are also at increased risk of melanoma. Melanomas usually develop on the legs and backs of women and the chests or backs of men. Importantly, melanoma is the most common skin cancer in young women.
What causes moles?
The cause is not known, however, there is a genetic connection in families with large numbers of moles, and many moles develop on sun exposed skin. Other possible causes are immune disorders and some drug treatments.
How can you tell if a mole is dangerous?
Dangerous moles change over time, their appearance evolves. In addition to their irregular appearance, color, shape, and size, other signs are bleeding, oozing, itching and pain or tenderness. This is the rationale for conducting self-exams on a monthly basis to examine your skin and find any suspicious lesions early.
The ABCDEs are the characteristics that can be used to evaluate your moles. Any one of these characteristics is a warning sign of melanoma. If you have a mole with any of these signs, please schedule a consultation with Dr. Heather Higgins.
- Asymmetry – one half of the mole does not mirror the other half.
- Borders – border are ragged, blurred or irregular.
- Color – the mole contains more than one color – tan, brown, black, blue, red and or white.
- Diameter – the diameter of the mole is larger than a pencil eraser or a quarter inch.
- Evolution – the mole is changing shape, size or color.
How are dangerous moles diagnosed?
An annual skin check with Dr. Higgins is important to visually assess your skin from head to toe. She will use the same criteria – the ABCDEs – along with a specialized tool called a dermatoscope to evaluate your moles. When she is concerned that a mole may be a risk, Dr. Higgins will take a biopsy that will be sent to a lab to be examined under a microscope. If she finds a dysplastic mole, she may recommend a wait and see approach, or recommend complete surgical removal depending on the degree of abnormality.
What are the treatment options for moles?
Most common moles are harmless and do not require treatment but may be cosmetically unacceptable. Harmless moles can be removed for cosmetic reasons, but risk factors like scarring and regrowth must be considered.
Treatment of biopsy-proven dysplastic nevi depends upon the extent of the abnormal cells:
- Mildly Dysplastic Moles rarely develop into melanoma and often require no treatment.
- Moderately Dysplastic Moles pose an intermediate risk of developing into melanoma and are usually excised.
- Severely Dysplastic Moles are at the highest risk of developing into melanoma, and complete surgical excision is recommended.
Dr. Heather Higgins is a board-certified dermatologist in Asheville, North Carolina. In her state-of-the-art practice she delivers compassionate, expert care personalized to each of her patients.
When you have a concern about a mole or another skin issue, contact our office to schedule a consultation.
