Why is mole screening necessary?
Mole screening is necessary because pigmented skin lesions can turn cancerous at an unpredictable time and in an unpredictable way, developing into melanoma skin cancer.
Regular mole examination is recommended because the sooner such a mole is spotted and surgically removed, the better the chances of a complete recovery.
How are moles examined?
Moles are examined with a portable handheld instrument called a dermatoscope, which allows the structure of pigmented lesions to be seen at ten times magnification. The examination depends on light from the instrument’s lamp entering the skin: under normal conditions it is reflected off the skin surface, and the unevenness of the upper horny layer increases that reflection further. By filling those minor surface irregularities with a transparent liquid (for example a colourless disinfectant solution), the difference in refractive index between air and skin disappears and the upper layer of the skin becomes more transparent. This creates the optical conditions needed to “look into” layers of the skin that cannot be examined with the naked eye.
Dermatoscopes that connect to a digital camera are now available, so the image of the examined mole can be stored on a computer in digital form. This method makes it possible to follow changes in pigmented lesions with greater certainty and precision. At follow-up examinations, comparing the magnified images shows exactly how the moles have changed over time, and at what rate.
How often should you have a mole screening?
Mole examination is generally recommended once a year — with the exception of those fortunate people who have no pigmented skin lesions at all.
Screening every six months is recommended for anyone who:
- has more than 50 ordinary moles
- has more than 12-15 so-called dysplastic moles
- has previously had melanoma skin cancer
- has a large congenital pigmented mole (a giant congenital naevus)
