What’s That Spot? A Guide to Skin Growths

Freckles, or ephelides, are typically small tan or brown spots with well-defined borders and often appear in clusters. Freckles only show up on skin that has been bare in the sunlight, and they get darker the more they’re exposed. When the sun hits the skin, it boosts production of melanin—the main pigment responsible for skin color—in skin cells called melanocytes. Anyone can get freckles, but they are more common in people with red or light hair. Freckles don’t pose a health threat. The best way to prevent them is to use sunscreen or stay out of the sun.

Moles, also called nevi, are common (most people have between 10 and 40 moles) round or oval growths that may be tan, brown, black, or pink. Moles happen when melanocytes grow in clusters in the skin, and the spots may be flat or raised. They can appear anywhere on your body and are sometimes with you from birth. Most moles are benign, meaning they are not cancerous. But moles that have a sudden change in appearance, irregular coloring or borders, or that are larger than six millimeters in diameter may hint at cancer and should be checked by a doctor.

Cherry angioma are small red lesions that usually appear on the torso, although these spots can show up anywhere on the body. If you apply pressure to the spots or to the skin around them, the red coloring momentarily disappears. This is because the lesions are a highly concentrated collection of blood capillaries. Cherry angioma usually first appear in adults over the age of thirty. While harmless, they may be removed for cosmetic reasons through surgery, burning, freezing, or laser treatment.

A white freckle, or idiopathic guttate hypomelanosis (IGH), isn’t really a freckle at all. These small white spots mostly occur on the arms and legs and appear to be caused by a loss of melanocytes and a decrease in melanin pigment. Anyone can get IGH, but it is more common as you age and is especially prevalent in people over 70 years old. IGH isn’t bad for you health-wise, but use sunscreen and avoid the sun as a possible preventative (IGH may be caused by UV light). Removal for cosmetic reasons may involve steroids creams, dermabrasion, or cyrotherapy.

A lentigo may look like a freckle, but it doesn’t get darker from UV exposure and it can occur anywhere on the body, including parts that haven’t been in the sun. There are three types. Lentigo simplex is a small spot between one and eight millimeters across. Solar lentigo— also called a liver spot, an age spot, or a sunspot—is usually much larger and can be induced by sunlight. Lentigo maligna is a large and patchy brown spot. The first two types don’t pose a health risk, but check with your doctor for especially dark or irregular lentigo malignas (most common in people over 60). These might require a skin biopsy, as a small percentage may develop into cancer.

Skin tags, or acrochorda, are flesh-colored raised spots that hang off of the skin. They can show up anywhere on the body, but they’re most common around the neck, groin, armpit, eyelid, under the breast, or anywhere else with regular skin folds. Because of the locations where skin tags are found, experts think they may be caused when skin regularly rubs against itself. Skin tags don’t pose a health threat, but they may be removed for cosmetic reasons with a simple surgery or by freezing (cyrotherapy) or burning (cauterization).

A wart is an infectious growth on the skin caused by the human papilloma virus, which leads to the unchecked proliferation of cells in the top layer of skin, the epidermis. Warts are usually rough and raised. There are several categories, including common warts (verrucae vulgares), which are typically circular and appear most often on the hands; plantar warts (verrucae plantares), which occur on the soles of the feet; and flat warts (verrucae planae), which are broad and flat and appear on the face, neck, the back of the hands, and the legs. Most warts go away on their own, but a dermatologist may treat them with medications, acid, or cyrotherapy.

These waxy, scaly round or oval growths may be tan, brown, or black, and they usually appear on the face, back, chest, or shoulders. Seborrheic keratosis might look alarming, but these lesions are actually the most common non-cancerous skin spots among older adults, usually appearing after the age of 50. Although seborrheic keratosis isn’t usually troublesome, if the spots are regularly irritated by clothing or jewelry, they may be removed surgically or with cyrotherapy.

The most common skin cancer is basal cell carcinoma, with around two million cases annually in the US alone. The cancer develops in the part of the skin where new cells are produced— the basal layer—and is usually a waxy, flesh-colored bump. Skin regularly exposed to UV light is most vulnerable; the cancer is most often found on the face, head, neck, and the backs of the hands. While basal cell carcinoma spreads slowly and is easy to treat, it is important to seek medical attention. Treatments include minor surgery, a rotation of scraping and killing the cancerous cells with electricity (curettage and electrodessication), cyrotherapy, medication, or a combination of chemical and light (photodynamic therapy). To prevent skin cancer, use sunscreen and avoid sun exposure when possible. And skip the tanning bed.

The second most common skin cancer is squamous cell carcinoma, with around 700,000 diagnoses in the US each year. The cancer occurs in the thin, flat squamous cells in the outermost layer of skin, or the epidermis. Squamous cell carcinomas are often scaly, rough sores that may bleed or crust, and although they occur in the areas most often exposed to UV radiation—the head, neck, and back of the hands—they may spring up on any part of the skin. When it is caught early, squamous cell carcinoma may be treated by curettage and electrodessication, photodynamic therapy, laser treatment, or surgery. Cases where the cancer can’t be cut out or otherwise removed may require radiation.

The most serious skin cancer is melanoma. Over 75,000 cases are diagnosed each year; in 2013, an estimated 9,480 people with melanoma will die. Melanoma occurs in the melanocytes. Often, though not always, it springs from moles. Experts recommend inspecting moles for ABCD (and sometimes E): Asymmetry (each half has a different shape), Border (the perimeter is uneven), Color (the color is patchy), Diameter (changes in size or diameters over six millimeters), and Evolving (the mole changes dramatically over a short period of time). Melanoma is treated with surgery. If the cancer has grown more deeply into the skin or spread to other parts of the body, treatment may also include immunotherapy, chemotherapy, radiation, and the surgical removal of lymph nodes.

MORE: True Story—”I Was Diagnosed With Melanoma”