A mole is called a nevus (plural: nevi) in medical jargon. They are thought to arise from the neural crest of the embryo, meaning they have a relationship to nerve cells and to the pigment forming cell, the melanocyte, which develops from the same rest. Many, if not all, have the ability to produce variable degrees of pigment, accounting for their characteristic tan to dark brown color. Some, on the face, for example, contain less pigment and look like slightly pink or flesh- colored round
bumps. Moles may be hairy or smooth. People of color have fewer than Caucasians.
Most people have between 10 and 40 moles. It is not uncommon to develop new moles until about age 40. Moles normally change over time. They can gradually get bigger, develop a hair, become more raised, get lighter in color, fade away, or fall off. Moles usually begin to form during the first twenty years of life. Often, they first appear as tiny brown specks, then they gradually enlarge. Most moles complete a sort of life cycle, slowly growing, then slowly fading until they disappear after about fifty years. A mole may sometimes slowly increase in size and gradually lighten in color before finally fading away. Some moles will become raised from the skin, and may eventually develop a small stalk and eventually fall off or be rubbed of by clothing. Other moles may grow hairs during their life cycle.
The changes in appearance described here occur very, very slowly. Any mole that suddenly changes in size or appearance, bleeds, or becomes painful or itchy, should be examined by your doctor. Very few moles develop into malignant growths, but any mole that doesn't fit the normal pattern needs to be evaluated. The Journal if the American Medical Association is one of several organizations that describe the ABCD method for evaluating pigmented skin spots. It is not known why they develop, but sun may be a factor. In infancy we have very few (less than 10) but in the 20-30 year old you can usually find about 30 on the entire body surface. As moles mature they very gradually enlarge(over years or decades), become tag-like and disappear or fall off. Most moles are less than 7 mm. If they are flat then the nevus cells reside in the upper skin layers (epidermis or epidermal-dermal junction). Moles that protrude have deep-seated nevus cells in the dermis. For this reason simply shaving them off may not get rid of all the pigment.
If you have a mole that you would rather do without, fifty years is a long time to wait and see if it will disappear without treatment. The most common removal method is surgical excision, a quick, simple procedure. If the mole is large, a stitch may be needed to pull the surrounding skin back together, but most moles don't require anything this elaborate. Moles located in conspicuous places, or in areas of the skin that are rubbed or shaved may be candidates for removal. Although shaving over a mole won't cause it to become malignant, the repeated irritation can become annoying enough to warrant removal of the mole. Moles can also be made less conspicuous by using special cosmetics. If laboratory analysis confirms that a mole is cancerous, the dermatologist will remove the rest of the mole. Patients should realize that slicing off a section of a malignant mole will not cause the cancer to spread. Removing a mole for cosmetic reasons involves numbing the area and using scissors or a scalpel to remove the elevated portion. The patient is left with a flat mole the same color as the original growth. Cutting out parts of the mole above and beneath the surface of the skin can leave a scar more noticeable than the mole.
Scissors or a razor can be used to temporarily remove hair from a mole. Permanent hair removal requires electrolysis or surgical removal of the mole. Wearing a sunscreen and limiting sun exposure may prevent some moles. Anyone who has moles should examine them every month and see a dermatologist if changes in size, shape, color, or texture occur or if new moles appear.