There are several skin lesions that are very common and almost always benign (non-cancerous). These conditions include moles, freckles, skin tags, benign lentigines, and seborrheic keratoses.
Moles are growths on the skin that are usually brown or black. Moles can appear anywhere on the skin, alone or in groups.
Most moles appear in early childhood and during the first 20 years of a person’s life. Some moles might not appear until later in life. It is normal to have between 10 to 40 moles by adulthood.
As the years pass, moles usually change slowly, becoming raised and lighter in color. Often, hairs develop on the mole. Some moles will not change at all, while others will slowly disappear over time.
Moles occur when cells in the skin grow in a cluster instead of being spread throughout the skin. These cells are called melanocytes, and they make the pigment that gives skin its natural color. Moles might darken after exposure to the sun, during the teen years, and during pregnancy.
Most moles are benign. The only moles that are of medical concern are those that look different than other existing moles or those that first appear after age 20. If you notice changes in a mole’s color, height, size, or shape, you should have a trained physician evaluate it. You also should have moles checked if they bleed, ooze, itch, appear scaly, or become tender or painful.
Examine your skin with a mirror or ask someone to help you. Pay special attention to areas of your skin that are often exposed to the sun, such as the hands, arms, chest, neck, face, and ears.
If your moles do not change over time, there is little reason for concern. If you see any signs of change in an existing mole, if you have a new mole, or if you want a mole to be removed for cosmetic reasons, talk to your physician.
The following ABCDEs are important signs of moles that could be cancerous. If a mole displays any of the signs listed below, have it checked immediately by a physician:
Melanoma is a form of skin cancer. The most common location for melanoma in men is the back; in women, it is the lower leg. Melanoma is the most common cancer in women ages 25 to 29.
Congenital nevi are moles that appear at birth. Congenital nevi occur in about one in 100 people. These moles might be more likely to develop into melanoma than are moles that appear after birth. If the mole is more than eight inches in diameter, it poses a significant risk of becoming cancerous.
Dysplastic nevi are moles that are larger than average (larger than a pencil eraser) and irregular in shape. They tend to have uneven color with dark brown centers and lighter, uneven edges. These moles tend to be hereditary. People with dysplastic nevi might have more than 100 moles and have a greater chance of developing malignant (cancerous) melanoma. Any changes in the mole should be checked by a physician to detect skin cancer.
If a physician believes the mole needs to be evaluated further or removed entirely, he or she will first take a biopsy (small tissue sample of the mole) to examine thin sections of the tissue under a microscope. This is a simple procedure. (If the physician thinks the mole might be cancerous, cutting through the mole will not cause the cancer to spread.)
If the mole is found to be cancerous, the physician will remove the entire mole by cutting out the entire mole and a rim of normal skin around it, and stitching the wound closed.
A skin tag is a small flap of tissue that hangs off the skin by a connecting stalk. Skin tags are benign and are not dangerous. They are usually found on the neck, chest, back, armpits, under the breasts, or in the groin area. Skin tags appear most often in women, especially with weight gain, and in elderly people.
Skin tags usually don’t cause any pain. However, they can become irritated if anything such as clothing or jewelry rubs on them.
Your physician can remove a skin tag by cutting it off with a scalpel or scissors, with cryotherapy (freezing it off), or with electrosurgery (burning with an electric current).
A lentigo (plural: lentigines) is a spot on the skin that is darker (usually brown) than the surrounding skin. Lentigines are more common among whites, especially those with fair skin.
Exposure to the sun seems to be the major cause of lentigines. Lentigines most often appear on parts of the body that get the most sun, including the face and hands. Some lentigines might be caused by genetics (family history) or by medical procedures such as radiation therapy.
There are several methods for treating lentigines:
The best way to prevent lentigines is to stay out of the sun as much as possible. Use sunscreen when outdoors, and avoid using a tanning bed to get a suntan.
Freckles are small brown spots usually found on the face and arms. Freckles are extremely common and are not a health threat. They are more often seen in the summer, especially among lighter-skinned people and people with light or red hair. Both men and women get freckles at an equal rate.
Causes of freckles include genetics, diseases (such as xeroderma pigmentosum, a rare disease that causes an increased sensitivity to ultraviolet light, such as the sun), and exposure to the sun.
Since freckles are almost always harmless, there really is no need to treat them. As with many skin conditions, it’s best to avoid the sun as much as possible, or use a sunscreen. This is especially important because people who freckle easily (such as lighter-skinned people) are more likely to develop skin cancer.
If you feel that your freckles are a problem or you don’t like the way they look, you can cover them up with makeup.
Age spots (seborrheic keratoses) are brown or black growths usually found on the chest and back, as well as on the head. They originate from cells called keratinocytes. As they develop, seborrheic keratoses take on a warty appearance.
The cause of age spots (seborrheic keratoses) is unknown. They are seen more often as people get older. They do not lead to skin cancer.
Age spots (seborrheic keratoses) are benign and are not contagious. Therefore, they don’t need to be treated.
If you decide to have age spots removed because you don’t like the way they look, or because they are chronically irritated by clothing, methods for removing them include cutting them off, cryotherapy, and electrosurgery.
Age spots (seborrheic keratoses) can’t be prevented.
The most common types of cysts include epidermoid cysts, pilar cysts and milia cysts. It is not clear why it is that people develop these lesions, although there are numerous theories. These are slow growing lesions that can occur anywhere on the body (typically head and neck, chest and/or back) and usually don’t cause any discomfort. They can have an odorous cheese-like material within them, and uncommonly become red, inflamed, and tender. Cysts are best treated by surgical excision by your physician, and/or extraction for small milia cysts which occur on the face. Inflamed cysts are often injected with cortisone.