What is melanoma? The complete story

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There can be a lot to know when it comes to understanding melanoma. From diagnosing it to the different forms it takes, we look at the disease from all angles and explain the fundamentals of recognizing and protecting yourself from this deadly form of skin cancer.

First things first: what is melanoma?

Melanoma begins in melanocyte cells found in the innermost layer of the epidermis (the top layer of our skin). It occurs when those cells behave abnormally, growing excessively and taking over surrounding tissues. Melanomas can develop from existing moles or skin growths, but, more commonly, they will start as a new growth.

Melanoma is considered the most dangerous form of skin cancer as it typically will spread to other areas of the body, including organs if left untreated. Non-melanoma skin cancers, such as squamous cell carcinoma and basal cell carcinoma, are generally considered less dangerous as they are less likely to spread and can usually be treated with a simple surgery. It can occur anywhere on the body, including areas not exposed to the sun, like inside the mouth or the palms of the hands. Men are more likely to get melanomas on their back while women are more likely to experience them on their legs.

What causes melanoma?


Melanomas are caused by gene mutations. And while there are things that increase the risk factor for developing the gene mutations that cause melanoma, doctors are still unclear on how these factors trigger it to form.

According to the American Cancer Society, most of the gene changes commonly seen in melanoma cells are not inherited. In fact, most cases of melanoma are likely caused by radiation from sunlight; some studies even put incidences of skin cancer caused by sun exposure at around 95%. The UV (ultraviolet) rays from the sun damage skin cells’ ability to repair DNA. When this happens, the risk of cancer increases.

Some melanomas, especially those formed in areas that aren’t regularly exposed to sunlight, exhibit different gene changes. And it’s important to note that the risk of melanoma increases if someone in the family has had melanoma, with gene mutations being passed from one generation to the next.

If it is found early, it can often be cured through relatively simple surgery. But if it is caught at a later stage, it can spread to other areas of the body and be more difficult to cure.

More about: Causes of Melanoma

Is melanoma curable?

Almost always, yes – but only if it is found early enough. The key is recognizing a melanoma before it has spread too far and especially before it has spread to other parts of your body. These are called invasive melanomas and will cause the most deaths.

They are not the most common, however. In most cases, your melanoma can be removed surgically and no further treatment is required. If it is at a later stage you may require some further treatment such as chemotherapy or radiation.

What are the symptoms of melanoma?

Melanoma appears on the skin as a new spot or growth or a change in an already existing mole. A normal mole will be even in color, quite small and will have appeared during the early part of your life. Most importantly, a normal mole will arrive and stay the same. It won’t change and it won’t evolve. That is what really makes it normal.

The ABCDE checklist:

Dermatologists identify melanoma symptoms using the ABCDE method. This method shows you which signs to look out for when examining suspicious moles, spots or growths on your skin.

  • Asymmetrical – Melanomas are distinctly asymmetrical
  • Border – melanomas have uneven borders
  • Colours – melanomas will contain at least two distinct colours
  • Diameter – melanomas are bigger than ¼ inch across
  • Enlargement – melanomas grow in size over time

The evolution of your mole(s) has become the most important factor to consider when it comes to diagnosing a melanoma. Knowing what is normal for YOU could save your life. If a mole has gone through recent changes in color and/or size, bring it to the attention of a dermatologist immediately.

Read more: ABCDE Melanoma self check

Pay attention to changes

Your skin is always changing – in fact, your skin replaces itself all the time. So if you see something on your skin that doesn’t go away over the course of a month or so that means it sits in the lower layers of skin. It’s important that these weird skin abnormalities are checked out — they could be melanoma symptoms.

Melanomas can appear anywhere on the body such as between your toes, on your scalp, on the soles of your feet or on the genital area. Hidden melanomas should be checked immediately as they can develop very quickly.

It is even better if you can keep track of the size and shape of your moles and spots so that you will be able to show your doctor a timeline to help with diagnosis.

More mole symptoms

When your mole, spot or growth is acting strange

We all have moles and marks on our skin, and in almost all cases, they are a normal reaction to sun exposure and are not dangerous. But if your mole is taking on some strange characteristics, the time has come for a second opinion. To recap and cover some additional warning signs, see your doctor if a mole or skin growth:

  • Develops a crust or a scab
  • Sometimes bleeds
  • Is itchy
  • Feels tender
  • Is getting bigger or swelling
  • Is strangely shaped (ie. not round)
  • Has borders that are irregular
  • Includes lots of different colours or shades
  • Is bigger than the size of a pencil eraser in diameter
  • Has appeared recently

View examples of melanoma pictures

Melanoma Types

There are four common types of melanoma. Most forms are classified as in situ, meaning they only occur on the top layers of skin. The more rare forms that arise within deeper layers of our skin are considered invasive and dangerous as they are more likely to spread to other organs.

Superficial Spreading Melanoma

This type of melanoma is the most common. As the name suggests, it forms on the top layers of skin and usually presents itself as a thin patch that spreads outwards, known as the radial growth phase. This patch often begins from an irregular mole (or dysplastic nevus).

This type of melanoma almost always occurs in light-skinned individuals as a result of sun exposure, commonly appearing on the trunks of men and legs of women. If left untreated, it can eventually spread to lower layers of skin and become more dangerous.

More about: Superficial spreading melanoma

Nodular Melanoma

This is the second most common type of melanoma and more invasive than superficial spreading melanoma. Nodular melanoma is characterized by the way it grows vertically. Starting as a bump on the skin’s surface, this type of melanoma roots downwards into the fat, blood and tissue of the body. This makes it more dangerous as it increases the cancer’s chance of surviving and spreading to other areas.

Nodular melanoma is also different from normal types of melanoma because it is harder to identify with the ABCDE method of skin cancer detection. This form of melanoma can be any color and feels firmer than normal moles or growths. Its growth isn’t always in diameter but in depth. If you are suspicious about any mole or growth, even if it doesn’t fit within the ABCDE symptoms, insist to have it biopsied by a doctor.

More about: nodular melanoma

Lentigo Maligna Melanoma

This type of melanoma is most common in elderly people. It is similar to superficial spreading melanoma in that it usually begins as a group of malignant cells that spread on the surface of the skin. Over time, the lentigo maligna can worsen and move to lower layers of the skin.
Once it invades deeper layers, it is considered a melanoma. It normally is seen on the head and neck and looks like brown, mottled patches or bumps.

More about: lentigo maligna melanoma

Acral Lentiginous Melanoma

This type of melanoma also spreads along the top layers of skin before penetrating deeply; however, it is unique as it is usually found on the palms, soles and under the nails, occurring in areas of the body that don’t grow hair and may or may not be exposed to sunlight. This is the least common type of melanoma in Caucasian people and the most common form in people of African and Asian descent.
It is observed as long tan, black or brown streaks under the fingernails or as dark spots or patches on the palms or soles of the feet. This type of melanoma is slow-growing at first and can often look like harmless discolored patches. Once nodules begin to form, it’s a sign that the cancer has spread deeper and is more deadly.

Melanoma treatment

Treatments for melanoma can range from simple mole removal to radiation therapy for more serious cases. There are four stages of skin cancer, which increase in severity.

Depending on which stage melanoma is in and how deep it has spread throughout the skin, treatments vary accordingly. Based on the type and stage of the cancer, the best treatment options should be discussed thoroughly with your doctor.

More about: What are your options for mole removal?


Melanoma prevention

The best way to prevent melanoma is to limit your sun exposure and apply sunscreen frequently. Those with fair skin are more at risk for developing melanoma as they have lower amounts of protective melanin (pigment) in their skin. It’s important to check your body from head-to-toe frequently to detect any dangerous changes in moles or spots early.

Self-checks are the first step; if you have any concerns about a spot or growth, get in touch with a doctor or dermatologist immediately to have it checked out. While the vast majority of moles and body marks are not cancerous, it’s always better to be safe than sorry.

More about Melanoma prevention

Download SkinVision to check for signs of cancerous moles. It’s free and an easy way to give you an added layer of security when checking for melanoma.

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What is melanoma? The complete story 1
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"The melanoma could have been on my arm for years"
Andrew Bartlett
United Kingdom
"The melanoma could have been on my arm for years"
Andrew Bartlett
United Kingdom

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