What to watch for

What you are looking for is change in size, shape and color. The features of change to watch for in moles are the A, B, C, and Dís of detection.

Border irregularity
Color variation


Normally, moles will grow in a symmetrical, even fashion. When one area is growing faster than another, it leads to irregular uneven outgrowths producing an asymmetrical appearance. Moles that are symmetrical can be folded along an axis to produce a mirror image. Moles that are asymmetrical have no axis that allows them to fold perfectly on to them self.


Much like symmetry, the outward edge of a normal mole is well defined and sharp, however, when the borders become irregular, hazy or ill defined, it is an indication that there may be uncontrolled localized growth.


Moles normally have a very uniform color or pigment. When the color starts to vary with the appearance of black or dark brown areas and the development of red, gray or white changes within a mole it is time to get a medical evaluation.


Most moles achieve a stable size over time. Moles that progressively increase in size after the age of 20 and particularly those that get larger than 1 cm should be evaluated.

Understanding the cardinal changes of ABCD can lead to the early detection of potentially abnormal lesions and prevent serious consequences. It is especially important for those who have had abnormal moles removed or have a family history of malignant melanoma to carry out their own regular skin review. At least 50% of all malignant melanomas are discovered by skin self examination. Early detection, diagnosis and treatment can improve the cure rate for malignant melanoma.

Click here for 19 different images of malignant melanoma, with specific features of change identified in each.