Few, if any of us, are lacking in at least a small number of moles, and in some individuals there are literally hundreds of them. Most are small, perhaps 1/4-1/2 inch in length. and are to be found almost anywhere on the skin.
They are mostly tan, brown or blue-black in color, often slightly elevated. and may bear a few hairs. It is not practical to remove most moles, nor is it necessary. If a mole is considered to be a cosmetic problem the doctor can easily remove it, often by as simple a procedure as cauterizing. This will, of course, result in a small scar. In general moles are to be regarded as harmless.
An exceedingly rare tumor related to moles is known as a melanoma. Melanomas may arise in a pre-existent type of mole (known as the junctions nevus) which appears as a generally flat, blue to black, hairless pigment spot in the skin. Some also appear to arise in apparently normal skin without a preceding nevus. Melanomas occur most often on the hands, feet or genitals. Any mole that enlarges, becomes darker or develops nearby new pigment spots, ulcerates or bleeds should be called to the doctor’s attention.
None of these moles is in any way related to the patchy pigmentation of the skin that occurs in some pregnancies. This is most marked on the face and resembles patches of tan. It is sometimes so extensive as to be called “the mask of pregnancy.” It is probably due to a pigment-controlling secretion from the pituitary gland. The pigmentation recedes after the delivery.