ABCDE rule for checking moles

How do you know if a mole is malignant?  It is not easy and even experts can be fooled occasionally. You need to look carefully and follow the ABCD rule. Generally, a mole that is not changing over many years is perfectly harmless. Moles that are undergoing malignant transformation are always growing quickly. That is, over a period of weeks to months, not years. This is why the E rule (evolving) is important. Another valuable point is that new harmless moles are common in teenagers and young adults, but a new mole in someone over the age of 40yrs, has a fair chance of being malignant.


A – Asymmetry: Normal moles or freckles are roughly symmetrical. If you were to draw a line through a normal spot, you would have two symmetrical halves. In cases of skin cancer, spots don’t look the same on both sides.

B – Border: A mole or spot with blurry and/or jagged edges.

C – Color: A mole that is more than one or two colours is suspicious and needs to be evaluated by a doctor. This can include lightening or darkening of the mole.

D – Diameter: If it is larger than a pencil eraser (about 1/4 inch or 6mm), it needs to be examined by a doctor. But, don’t be fooled by size alone – it can be smaller.

E – Elevation/Evolving: The mole is actively growing over a period of weeks to months. (normal moles grow slowly over a period of years)

Basically, any mole that is CHANGING over weeks to months needs to be checked.
For reassurance, do take photos of your moles, with a ruler in the photograph. It is very easy to do with a smart phone. This is helpful to establish that your moles are stable

If taking your own photos is difficult, then I can do them for you, here at the clinic.