Moles (medically known as a naevus or naevi) are the commonest growth found on the skin where individuals frequently have one or more moles. Moles are benign tumors that come from melanoctyes. Melanocytes are found in the basal layer of the epidermis, superficial to the dermal layer. These cells produce pigment called melanin, which is responsible for different skin colour. Melanin is packaged into small parcels (or melanosomes), which are then transferred to skin cells (keratinocytes).
As such, they are easy to observe and monitor for any changes which may occur in their character. Moles are benign when they exhibit symmetry, have a regular border, uniform pigmentation and are smaller than a pencil’s eraser. Most are of little medical concern.
What does a normal mole look like?
Moles are incredibly variable in their morphology. Apart from the commonest brown / tan type of moles, there are pink moles, red moles, flat moles, raised moles, light moles, speckled moles, blue moles, mature moles: a photo gallery is shown at the end of this article.
When should I be concerned?
What are the implications of change in the characteristics of a naevus? Change may mean instability (or dysplasia) or in the worst case scenario, the development of a black skin cancer (melanoma).
In Hong Kong, melanomas are uncommon by comparison to non-melanomatous skin cancers. These are basal cell or squamous cell carcinomas and combined, are the seventh commonest type of cancer in Hong Kong. However, there is no room for complacency in looking after your skin and detecting change in your moles.
So, what are the worrying signs I should be looking out for?
Know your A’s to E’s Rules
Changes in the size, shape, colour, or feel of a mole is often the first warning sign of melanoma. These changes can occur in an existing mole, or melanoma may appear as a new or unusual-looking mole. The "ABCDE" rule is helpful in remembering the warning signs of melanoma:
A Asymmetry: the two halves of the mole do not match
B Border: the edges are irregular or uneven (scalloped, blurred, ragged or notched)
C Colour: increasing, reducing and uneven pigmentation. Multiple or changing shades of brown, tan, black, red, blue or pink are present
D Diameter: larger than a pencil eraser, which means that the mole appears larger that 6 millimeters or is growing in size both in height and diameter
E Evolution, stands for changing or a newly appeared mole with or without symptoms: ulceration, bleeding, itchiness, oozing or flakiness
Once you know the signs to be watching out for, it is recommended to pay even closer attention to sun exposed areas of your body as ultraviolet radiation is one of the many risk factors for the development of changes in moles. Other risk factors will be discussed in a separate article.
So, what do I do if I notice an increasing number of moles, new moles, or some worrying change in my moles?
It is highly recommended to visit a doctor for skin examination, and if concerned about a particular type of naevus, the doctor may recommend a skin biopsy to remove the mole under local anaesthesia. Another indication for mole removal of a regular mole is where it is irritated by clothes and underwear.
If you want to learn more about your skin or/and examine your moles, please make an appointment with a specialist doctor at 2715 4577 via email firstname.lastname@example.org.