Author: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand, 2006. Dr Amanda Oakley is a consultant for MoleMap NZ.
The term ‘mole mapping’ has been used in several different ways. However, it usually refers to a surveillance programme for those at high risk of malignant melanoma. It may include a clinical skin examination and dermoscopy to identify and evaluate lesions of concern.
Mole mapping might simply involve marking spots on a cartoon drawing of the body (see self skin examination) to indicate the position of skin lesions of concern, particularly moles and freckles. Mole mapping is more likely to refer to conventional print photographs or digital images of the whole body's skin surface. These can be reviewed at a later date to see if there are any new skin lesions, or whether pre-existing skin lesions have grown or changed colour or shape.
Some systems rely on automated machine detection of new or changed lesions and/or automated diagnosis. These machines are increasingly accurate but should not be used as a substitute for clinical evaluation by a doctor.
Sophisticated digital mole mapping programmes may include the following:
The patient will be asked to remove at least outer clothing. Let the staff know if you feel uncomfortable, especially if there are lesions of concern hidden by your underwear. Make-up, nail varnish and jewellery should be completely removed prior to the procedure. Long hair should be tied up.
Lesions of concern are those that have features consistent with melanoma or other form of skin cancer (such as basal cell carcinoma or squamous cell carcinoma). Characteristically, skin cancers enlarge or change over periods of weeks to years.
The characteristics of melanoma are defined by the ABCDE rule and the Glasgow 7-point checklist. These are a useful guide, but may not identify early melanomas or atypical forms. Not all skin lesions with these characteristics are melanomas; many turn out to be harmless.
|ABCDE rule||Glasgow 7-point checklist|
Diameter over 6 mm
Evolving (enlarging, changing)
Change in size
Change in sensation
Nonmelanoma skin cancers are much more common than melanoma. These usually present as growing skin lesions, that may be crusty, ulcerated or bleeding.
If you have any skin lesions that worry you because they are new, enlarging or look distinctive or unusual, ask your doctor's advice. If your doctor is also concerned, he or she may advise removal (biopsy), follow-up appointment, referral to a specialist, or mole mapping.
Mole mapping is particularly useful for individuals who have:
Mole mapping is most useful for pigmented moles – these are usually light to dark brown in colour. Accurate diagnosis depends on evaluation of the structure of the pigment.
Mole mapping is intended to diagnose melanoma at the earliest possible stage, by identifying new melanocytic lesions or change in pre-existing melanocytic lesions. These features may be suspicious of melanoma if the lesion also has a disordered structure clinically or on dermoscopy.
Compared to self skin examination or an examination by a non-specialist doctor, mole mapping as described above has the following advantages:
Mole mapping is a relatively new procedure and is considered experimental by many dermatologists, as it has not yet been proven to save lives. Like all screening systems and other medical procedures, mole mapping is not without risks.
If you are considering undergoing mole mapping, discuss the procedure with your own doctor. Ensure:
See the DermNet NZ bookstore
© 2018 DermNet New Zealand Trust.
DermNet NZ does not provide an online consultation service. If you have any concerns with your skin or its treatment, see a dermatologist for advice.