Moles are flat or elevated, flesh coloured to dark-brown markings located randomly over the entire skin surface. So, they can ocur anywhere on skin or mucosal surfaces of the body.
Moles are overgrowths of the skin's pigment cells (melanocytes). They are a clump of cells with different pigment (colour) than the surrounding skin. The surface of moles varies from smooth to pebbly and may contain heavy dark hairs or no hair growth. The number and type of moles that a person has is largely determined by family history.
Moles are generally medium to dark brown in colour though they range from skin coloured to black. The majority of moles are flat, relatively even in colour and regular in shape. The number of moles that develop in an individual is determined by both genetic (inherited) factors and by sun exposure.
Apart from the ABCDE (Elevation) criteria for assessing moles, a different looking mole should be reviewed by your doctor since normal moles usually resemble one another. A new mole after the age of 25 should also be reviewed by your doctor.
Melanoma is cancer of the pigment cells. Only approximately 30% of melanomas arise from moles.The changes of melanoma are generally detectable over a period of months. Changes that develop over days are almost always due to inflammation or injury and it is appropriate to wait for a week or two to allow sudden changes to go away. If the change fails to revert to normal and continues for more than a month you should see your doctor.