Moles

What are moles?

A mole, or naevus, is a normal skin growth that develops when pigment-producing cells (melanocytes) grow in groups. They appear as small, dark marks, or sometimes flesh-coloured small bumps, on your skin.

Moles can appear in a range of different colours, shapes and sizes. For example, one type of mole is the blue naevus. Blue moles look blue because the group of pigment-producing cells is lower in the skin than brown freckles and moles. They might look unusual but are generally benign.

Most people have moles. Only about one in a hundred persons has a mole or moles present at birth. These so called congenital melanocytic naevi are often bigger than acquired naevi (moles) that develop after birth. Moles typically appear in childhood and early teenage years, so that by the age of 15, Australian children have an average of more than 50 moles.

What is the difference between a mole and a freckle?

Moles tend to be raised from the skin’s surface whereas freckles are flat. Like moles, the colour associated with freckles is due to the presence of melanin that is formed in melanocytes that has appeared or darkened with sun exposure. Moles appear when skin cells form a cluster. Freckles have a normal number of pigment-producing cells and cannot turn into moles.

Cancerous moles

Most moles are harmless. However, some types can develop into skin cancer. Overexposure to the sun, especially in childhood, can increase the number of moles, and people with a lot of normal moles can have a higher risk of developing melanoma.

Irregular moles (dysplastic or atypical naevi) are a sign that a person has an increased risk of developing melanoma and the risk increases with the number of moles a person has.

It is important to get to know your skin and check it regularly.

What about other skin spots?

Not all spots that appear on your skin are cancerous. Anyone can develop sunspots, also known as actinic or solar keratoses, but they more often occur in people aver the age of 40. Sunspots usually appear on skin that is frequently exposed to the sun such as the hands, forearms, lower legs, neck and head. They are a warning sign that the skin has had too much exposure to the sun and this can increase the risk of developing skin cancer.

How do I check my skin?

In a room with good light, fully undress and use a full-length mirror to check your whole body. For areas that are hard to see, use a handheld mirror or ask someone to help.

Skin cancers don’t all look the same but there are signs to look out for such as:

• a spot that has changed size, shape, texture or colour
• new moles or spots that look different from other spots
• a sore that is itchy or bleeds
• a sore that doesn’t heal within a few weeks
• a crusty or flaky appearance developing on a mole.

Normal moles usually look alike so if you notice a new or changing spot, ask your doctor to examine it. It can be difficult to know if something on your skin is a harmless mole, sun damage or a sign of cancer. When in doubt, talk to your GP.

Where can I get reliable information?

Call Cancer Council on 13 11 20 for further information and support. You can also read Cancer Council’s booklets, Understanding Skin Cancer and Understanding Melanoma.

Sources

• Understanding Skin Cancer, Cancer Council Australia © 2020. Last medical review of source booklet: January 2020.
• Understanding Melanoma, Cancer Council Australia © 2021. Last medical review of source booklet: January 2021.
• Health Direct