A benign nevus (mole) typically looks uniform, symmetrical, single-colored (pink, tan, brown, or black), with a clear border, and is usually small (pencil eraser size) and stable over time, though they can be flat or raised, smooth or wobbly, and sometimes have hair. Common types include flat junctional nevi, slightly raised compound nevi, and dome-shaped intradermal nevi, which might have hairs growing from them.
Benign nevi are usually a single color, ranging from skin-colored to dark brown. They are typically round or oval-shaped. In addition, benign moles are symmetric, that is, when a line is drawn within them, the two halves have the same appearance. Most melanocytic nevi are the size of a pencil eraser or smaller.
These marks are thought to be caused by a localized increase in melanocytes as a baby grows in the womb. Melanocytes are the skin cells that produce melanin, which gives skin its color. A nevus has an increased amount of melanocytes. The condition is thought to be caused by a variant gene.
A benign mole can sometimes develop into skin cancer. Skin cancer arising from a benign mole is malignant melanoma, which is a very dangerous type of skin cancer that can be fatal if not treated early.
Blue nevi are blue-gray to blue-black moles that are present at birth or appear later in life. They are categorized into either a “common blue nevus” or a “cellular blue nevus.” The common blue nevus is typically flat or dome-shaped with a smooth surface and ranges in size from a 0.5-1cm.
Often the first sign of melanoma is a change in the shape, color, size, or feel of an existing mole. Melanoma may also appear as a new colored or otherwise unusual area on the skin.
C is for Color.
Multiple colors are a warning sign. While benign moles are usually a single shade of brown, a melanoma may have different shades of brown, tan or black. As it grows, the colors red, white or blue may also appear.
People can be born with harmless eye nevi. A pigmented spot that develops later in life is usually harmless as well, but may have a greater risk of becoming cancer. An eye nevus needs to be watched regularly by an ophthalmologist because, like a skin mole, it could possibly develop into cancer of the eye.
Can a doctor tell if a mole is cancerous just by looking at it? If the skin cancer is starting to advance, then yes, the symptoms may be obvious to the naked eye. However, early melanoma symptoms aren't always visible at a glance.
The rate is similar between men and women younger than 40 years but becomes substantially higher for men older than 40 years. For a 20-year-old individual, the lifetime risk of any selected mole transforming into melanoma by age 80 years is approximately 0.03% (1 in 3164) for men and 0.009% (1 in 10 800) for women.
Changes in benign moles
Environmental factors such as exposure to sunlight, and hormonal changes such as going through puberty or pregnancy can cause moles to darken or develop. Therefore, the appearance of moles can change over time. They can change in number and appearance and can also fade away.
In fact, melanoma is rare in young children. Even so, there are times when a mole should be checked by a dermatologist just to be sure. Caught early, melanoma is highly treatable. The following can help you decide when a dermatologist should examine your child.
What is a congenital nevus? A congenital nevus, also known as a mole, is a type of pigmented birthmark that appears at birth or during a baby's first year.
Surgical Care
Melanocytic nevi can be surgically removed for cosmetic considerations or because of concern regarding the biologic potential of a lesion. Melanocytic nevi removed for cosmesis are often removed by tangential or shave excision. Punch excision can be used for relatively small lesions.
A common mole (nevus) is a small growth on the skin that is usually pink, tan, or brown and has a distinct edge. A dysplastic nevus is often large and does not have a round or oval shape or a distinct edge.
There are several reasons that patients sometimes decide to undergo removal of a large nevus. Most of the time, the overriding reasons to remove a congenital pigmented nevus are first to reduce melanoma risk and second to improve appearance which can be fundamental to improving a patient's overall psychosocial state.
Three key warning signs a mole might be cancerous, often remembered by the ABCDE rule, are Asymmetry (uneven halves), irregular Border (jagged edges), and varied Colour (multiple shades like brown, black, red, blue). Other major signs include evolving changes (size, shape, elevation), bleeding, itching, or a sore that won't heal, especially if it looks different from your other moles (the "ugly duckling").
Yes, your General Practitioner (GP) can and should check moles, especially if you notice changes, as they are trained to perform initial skin checks, use magnifying tools like dermoscopes for closer inspection, and can determine if a mole is suspicious enough to warrant a referral to a dermatologist or further testing like a biopsy. GPs can manage simple skin concerns and refer you for more complex issues, so seeing your GP is the crucial first step when you're worried about a mole.
Having a mole biopsy should not be painful, but may cause some discomfort. Patients receive numbing medication before the biopsy is done.
Precancerous moles, also known as dysplastic nevi, are atypical moles that exhibit irregular characteristics. While they're not cancerous themselves, they can indicate an increased risk for developing melanoma or other skin cancers. Monitoring these moles for changes in size, shape, color, or borders is crucial.
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Types of Moles
Moles are primarily categorized by when they appear, what they look like and their risk of becoming cancerous. Congenital nevi – often called birthmarks because they are present a birth. Acquired nevi – these are common moles that appear after birth, and can appear at any time.
Superficial spreading melanoma
70 to 80 out of every 100 people with melanoma (70% to 80%) have this type. It can develop anywhere on the body. But in men it's most common on the central part of the body (the trunk). And in women, it's most common on the legs.
They are described as “hazy” because the precancerous mole fades into the healthy skin. Color: Whereas a common mole is one color, a precancerous mole is often a mixture of various colors like brown, black, red, or blue. Diameter: The larger the mole, the more likely it is precancerous.
General symptoms of advanced melanoma
hard or swollen lymph nodes. a hard lump on your skin. unexplained pain. feeling very tired or unwell.