1. What is a mole or naevus?
Moles or naevi are benign proliferations of melanocytes, the skin cells that produce melanin. They are usually present in childhood and adolescence, and tend to enlarge slowly (over years) and increase in number until the third decade of life. Sun exposure can turn moles darker and stimulate new moles to develop in young people. However, genetic background (e.g. family history of moles) is the main factor that determines how many moles a person will get. They can develop at any site, including lips, oral cavity, eyes, genitals and nails.
Moles are usually flat brown to black single coloured spots. Some will become raised and lighter or skin-coloured with time. They are often regular and symmetrical in pattern and shape.
2. Should moles be removed?
Moles are very common. Most Caucasian young adults have at least 15-30 of them. The chance of an individual naevus turning into a melanoma is very low. In fact, the majority of melanomas (more than 60%) do not arise from moles. Therefore, preventive excision of benign looking moles is not recommended. Only the ones that look suspicious or that change considerably over time should be removed to rule out melanoma and complete excision biopsy with a 2 mm margin is recommended. New spots looking like moles arising after the age of 50 can be in fact early stage melanomas, and should also be considered suspicious. In general, avoiding unnecessary excisions while diagnosing melanomas at an early stage is the current standard of care at the SMDC.
3. What is a dysplastic naevus and dysplastic naevus syndrome?
Dysplastic naevus is a “funny-looking” mole. It may be ill-defined, asymmetrical, irregular and have multiple colours, resembling a melanoma, but is still considered a benign lesion. The risk of a dysplastic naevus turning into melanoma is also very small and does not justify the removal of such lesions unless they look different from the other moles (“ugly duckling” sign) or change considerably over time.
Nevertheless, people having multiple dysplastic naevi are more at risk of developing a melanoma anywhere in the skin, especially, individuals with:
More than 100 naevi
More than 6 looking “dysplastic”
At least one greater than 8 mm in diameter
A person that presents all these three features can be considered to have the so-called “dysplastic naevus syndrome”, and should be closely monitored.
It may sound confusing, but dysplastic naevi should be better considered as a predictor of higher-risk for melanoma rather than lesions that will themselves turn into a melanoma.
4. How do I check my own moles?
We advise patients to check their own skin every 3-4 months. This is best done in front of a full-length mirror. To check the skin on your back you can use a handheld mirror in front of the full-length mirror or ask a relative, friend or partner to help you. We also recommend asking your hairdresser to look out for any lesion on your scalp.
If any spot looks irregular (see melanoma pictures and description), or has changed in any way, you should see your doctor as soon as possible.
5. What is “Total Body Photography” and should I have it done?
We understand that for people who have multiple moles, it may be challenging to know them “by heart” and detect changing or new spots. In these cases, it is very useful to have a baseline “Total Body Photography” (TBP), that is a medical documentation of the whole skin, head to toes, in a series of photos taken in standardized positions.
At SMDC, the TBP is taken by a professional medical photographer, with the aid of a German imaging device, called DermoScan X2, that allows automatic comparison of photos taken at different intervals. Every new or changing lesion since the last examination, comparing to current pictures, is detected automatically, by a computer and then carefully checked by a dermatologist. The complete set of images is stored in a USB and given to patients, so that they can be used at home during skin self-examination. We recommend repeating the TBP yearly for automatic comparisons.
TBP can be useful to any person, however, it is particularly indicated for people with more than 100 moles and/or with an increased risk of melanoma (dysplastic naevus syndrome, personal history of melanoma, family history of melanoma).
6. How can moles be differentiated from melanomas?
Most moles can be differentiated from melanoma by naked eye inspection combined with dermoscopy, a handheld magnifying device. A minority of them, however, are more difficult to diagnose and may require observation over time, with the aid of Total Body Photography (LINK) or Digital Dermoscopy Monitoring. More advanced techniques, such as In Vivo Confocal Microscopy and Nevisense®, both available at SMDC, can also be useful to differentiate moles from melanoma, leading to both early detection of melanoma and a reduction in unnecessary biopsies.