Understanding moles: Types, risks and how to keep your skin safe

A Toronto-based dermatologist says Canadians should be making self-examinations a habit.

While most moles are harmless, some have the potential to become cancerous. (Canva)
While most moles are harmless, some have the potential to become cancerous. (Canva)

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Contact a qualified medical professional before engaging in any physical activity, or making any changes to your diet, medication or lifestyle.

Those who spent much of the summer months under the sun may find new or changing moles that can sometimes cause concern.

While most moles are harmless, some have the potential to become cancerous.

As summer winds down, dermatologist and leader of Toronto's DLK on Avenue Dr. Lisa Kellett tells Yahoo Canada that Canadians should be making self-examinations a habit.

Read on for everything to know about these skin anomalies, how to self-examine them and when removal might be necessary.

What are moles and skin tags?

Moles, known medically as nevi, are pigmented lesions that can vary greatly in appearance and type.

Kellett explained moles are usually pre-programmed from birth and come in a multitude of forms. Some are present from birth while others develop over time due to various factors, including sun exposure.

Skin texture black birthmarks and moles on skin of man photo. Moles are pigmented lesions that can vary greatly in appearance and type. (Getty)
Moles are pigmented lesions that can vary greatly in appearance and type. (Getty)

"'Moles' just refers to pigmented lesions of the skin, although there are many different types," Kellett said.

"It's important to see a dermatologist to be able to properly diagnose what type of mole you're dealing with."

Melanoma Canada identified the following types, among others:

  • Compound nevi: raised and skin-coloured

  • Acquired nevi: appear during childhood or adulthood

  • Blue nevi: blue-grey to blue-black moles, typically flat or dome-shaped with a smooth surface

  • Intradermal nevi: skin-coloured or light brown dome-shaped lesions

  • Splitz nevi: often pink, raised bump, but sometimes red, blue or black

Skin tags "are completely different," according to Kellett.

"They are not moles per se, although moles can masquerade as skin tags so that you can have what we call a 'pedunculated mole,'" she explained.

It might appear like a skin tag but contain benign cells, called nevus cells. Unlike moles, skin tags are not present from birth and tend to develop later in life.

How to self-examine moles

While most moles are harmless, some have the potential to become cancerous, that's why checking them out on a regular basis could be a life-saving measure.

"What I tell my patients is that we should be self examining moles once a month," Kellett claimed. "And what you're looking for is any change in size, shape, colour or border, or any new mole."

Close up detail of the bare skin on a man back with scattered moles and freckles. (Getty Images)
Dr. Lisa Kellet recommends people check their moles once a month. (Getty)

These characteristics, she explained, can indicate the presence of atypical cells.

"The ones that we really have to worry about are malignant melanoma — a type of skin cancer that can be deadly," she said.

According to the Canadian Cancer Society, people can follow the "ABCDE" rule when self-examining:

  • A: Asymmetry, when one half doesn't match the other

  • B: Border irregularity, when the mole has ragged or blurred edges

  • C: Colour variation within the mole

  • D: Diameter larger than a pencil eraser (usually more than 6 millimetres)

  • E: Evolving or changing in size, shape, colour or elevation

Kellet's recommendation is to set a specific date each month for thorough checks, and consider photographing hard-to-see areas to monitor changes over time.

"Have someone take a picture of your moles with a little ruler underneath," she said.

She also recommended choosing a time that's easy to remember. For example, women can pick the first day they begin their period.

Who is at risk of developing suspicious moles?

Why do some moles develop atypical cells? According to Kellett, "it's like the development of cancer, why does cancer occur, right?" she questioned.

"So we know that the sun and ultraviolet light exposure can cause changes in the skin to DNA, and can cause the development of skin cancer."

Be very diligent about sun protection.Dr. Lisa Kellett

Fair-skinned individuals are generally more susceptible to skin cancer due to reduced melanin protection, Kellett explained. People with conditions like albinism face even higher risks.

However, Kellett reminded that anyone, regardless of skin type, should practice regular self-examinations and sun protection.

"That would be one thing that we can do to prevent skin cancer, is to be very diligent about sun protection," she said.

Mole removal: Why and when

While some opt for removal for cosmetic reasons, others choose removal for health concerns.

Suspicious changes or discomfort are a good reason to request having a mole removed, Kellett said.

When considering mole or skin tag removal, Kellett emphasized the importance of professional assessment. Attempting self-removal with over-the-counter methods can be risky, she claimed.

"All moles should be sent for histopathological examination to make sure they're not cancerous," the expert said.

A dermatologist examines a birthmark of patient up close while checking for benign moles. (Getty)
Kellett says suspicious moles should be examined by professionals before removal. (Getty)

The removal process varies depending on the type of growth, Kellett added. Excising the mole with a scalpel is the most common technique, as the growth can then be sent for further examination.

Pathologists are "the best people to examine the skin," she shared, as they "examine the tissue underneath the microscope to determine the diagnosis and if it's benign or malignant."

Kellett suggested removal can be done year-round, contrary to the common belief that it's best to avoid the summer months.

But, she did warn against seeking treatments at spas or using over-the-counter devices without professional oversight.

Misdiagnosis and inadequate examination can lead to severe consequences, and even death in cases of a delayed diagnosis of malignant melanoma.

Let us know what you think by commenting below and tweeting @YahooStyleCA! Follow us on Twitter and Instagram.