Moles and melanoma

Updated: 03.08.2023
Approved by: General Practitioner, Alice Pan

Moles, commonly benign skin growths, are a familiar sight on human bodies. Yet, when these seemingly innocent spots undergo unexpected changes, they can signal a far more dangerous condition - melanoma. This malignant form of skin cancer, originating in the pigment-producing melanocytes, has seen an uptick in incidence over the years.

Moles

A mole, scientifically termed a nevus or nevi in the plural, represents an increased skin pigmentation. This augmented pigmentation can arise from an increase in melanin production, a proliferation of pigment-producing cells, or a blend of both. Universally prevalent, most moles are benign. They might be present at birth or develop primarily during early life, escalating in number until around age 25. The propensity to develop moles is higher in fair-skinned individuals and is influenced by sun exposure, genetics, and even hormonal shifts during pregnancy. The complexity of moles varies based on their location in the skin structure and appearance.

Melanoma

Melanoma, a grave form of skin cancer, originates in melanocytes – the cells responsible for melanin production that colours our skin and moles. While moles are the primary breeding grounds, melanoma can manifest anywhere, including under nails or within the eyes. This cancer stems from unchecked melanocyte division, often triggered by sun-induced DNA damage or specific genetic vulnerabilities. Timely detection and surgical removal, especially before it delves deeper into the skin, are crucial. However, a deeply rooted melanoma necessitates a more rigorous examination for any further spread due to its aggressive nature.

What should one keep an eye on?

Moles change throughout life. They are usually flat and blend with the surrounding skin in the beginning, but over time they may slightly raise or grow out from the skin. Around the age of 45-50, individuals typically stop developing new moles. Sometimes moles can also disappear. This often happens during adolescence when the immune system attacks the cells in the mole and it disappears. A white ring often forms around the mole initially.

When it comes to moles, it is important to be aware of:

changes in colour
changes in colour composition (if a part of the mole has a different colour compared to the rest or if multiple colours have developed)
rapid growth or asymmetric shape
changes in the surface of the mole (if it becomes rougher, develop sores, or easily bleeds)
itching from the mole

Mole check

A mole check with a doctor takes place by asking the doctor a number of questions about the mole(s). How long you've had it, whether it's changed, what changes you've noticed. The doctor will also ask if anyone in your close family has had mole cancer and if you have been exposed to high sun exposure. The doctor will then examine the mole and look for "danger signs", or factors that may increase the risk of mole cancer. These are asymmetry, irregular demarcation, colour change, diameter greater than 6 mm, and the development of the mole.

The examination usually involves the doctor using a dermatoscopy (a magnifying glass with good light and a ruler) to assess the mole. In dermatoscopy, you will be able to see small details in the mole and measure how big it is.

When should you do a check-up?

Do you experience uncertainties when moles form? See below for a checklist of when you should see a dermatologist for a consultation. You get a new mole A mole changes shape and colour Gets bigger than before, in thickness or in width Changes shape and gets uneven edges Changes colour, often with brownish-black areas A mole itch bleeds or forms a wound that will not heal.

Mole removing

The vast majority of general practitioners can remove moles, but if you are in doubt about the diagnosis, moles are very large or sitting in an unfavourable place (eg neck, face or scalp), most people tend to refer to a dermatologist. If you have a common mole, where none of the risk factors as described above are present, it is not necessary to remove the mole. Especially if it is on the chest/stomach of younger individuals, one will be reluctant to remove it, as it can form ugly scars afterwards. If an indication has been found to remove a mole, this is easily done under local anaesthesia, where the skin around the mole is anaesthetized and the doctor cuts away the mole by removing a small piece of the skin. The doctor will try to remove between 2-5 mm of the skin around the mole, in case there should be mole cancer, one always strives to get all the cells from the mole. The wound is then closed with a thread, where the stitches should sit for 10-14 days. For the first 3-4 days, it is advisable to keep the wound dry and avoid a lot of movement in the skin here. The doctor will send the mole that was removed to the laboratory for analysis, should it turn out to be cancer cells in it, the further course of it depends on how large it was if the entire mole was removed. The doctor who removed it will contact you to inform you about further treatment.

Prevention

Prevention centres around sun protection, diligent sunscreen application, and regular mole checks, especially for those with a high mole count or a family history of melanoma. Even moles that change in appearance, particularly those that darken, become irregular, or have jagged borders, warrant attention. Given melanoma's severity, early detection remains pivotal. Some melanomas originate in non-melanin-producing cells, making them relatively rare. However, a family history of melanoma intensifies the risk, underscoring the need for awareness.