Conditions - Moles

Moles, known medically as nevi, are clusters of pigmented cells that often appear as small, dark brown spots on your torso, face, arms and legs. But moles can come in a range of colors and can develop virtually anywhere, including your scalp, armpits, under your nails, and between your fingers and toes.

Most people have between 10 and 40 moles, although the number you have may change throughout life. New moles can appear into mid-adulthood, and because moles last about 50 years, some moles may disappear as you age.

The great majority of moles are harmless, but in rare cases, moles may become cancerous. Monitoring moles and other pigmented patches is an important step in the diagnosis of skin cancer, especially malignant melanoma. Although not all melanomas develop from pre-existing moles, many begin in or near a mole or other dark spot on the skin.

Types of Moles

• Congenital nevi - About 1-3% of all babies have one or more of these types of moles at birth.

• Junctional moles, which are usually brown and may be flat or slightly raised.

• Compound moles, which are slightly raised, range in color from tan to dark brown, and involve pigment-producing cells (melanocytes) in both the upper and lower layers of the skin (epidermis and dermis).

• Dermal moles, which range from flesh-color to brown, are elevated, most common on the upper body, and may contain hairs.

• Sebaceous moles, which are produced by over-active oil glands and are yellow and rough-textured.

• Blue moles, which are slightly raised, colored by pigment deep within the skin, and most common on the head, neck, and arms of women.

An estimated one out of every 10 Americans has at least one atypical mole. These moles are larger than common moles, with borders that are irregular and poorly defined. Atypical moles also vary in color, ranging from tan to dark brown shades on a pink background. They have irregular borders that may include notches. They may fade into surrounding skin and include a flat portion level with the skin. These are some of the features that one sees when looking at a melanoma. When a pathologist looks at an atypical mole under the microscope, it has features that are in-between a normal mole and a melanoma.

While atypical moles are considered to be pre-cancerous (more likely to turn into melanoma than regular moles), not everyone who has atypical moles gets melanoma. In fact, most moles -- both ordinary and atypical ones -- never become cancerous. Thus the removal of all atypical nevi is unnecessary. In fact, half of the melanomas found on people with atypical moles arise from normal skin and not an atypical mole.

Moles Suspicious for Cancer

• Those with spontaneous ulcerations or bleeding

• Those with symptoms such as pain and itching

• Congenital and giant Nevus or Moles

• Those showing changes in size and color

• Those with unexplained inflammatory changes

• Usually occurring in junction and compound moles

Treatment

Surgical excision should be done where cancer is a reasonable concern. Improving cosmetic appearance is another reason for excision, but all surgery leaves some scarring. Smaller nevi can be "shaved off". Larger ones can be cut out directly and the wound edges sewn together. Much larger nevi may be excised in stages by taking a little more out each time until the entire nevus is removed. This is called "serial excision." Cutting out very large nevi will leave behind a raw area that is too big to be sewn together and must be covered. This can be done with a split thickness skin graft from some other normal area of the body. The skin-grafted area will have varying degrees of scarring and will usually be thinner and more fragile than normal skin.