Published over 1 year ago, by Roeland Pater

Melanoma is the least common type of skin cancer, but it is the most deadly. According to the World Health Organization, there are about 132,000 new cases of melanoma worldwide each year, and although it only accounts for approximately 1% of skin cancer cases, melanoma is responsible for a large majority of skin cancer deaths. So what is melanoma exactly?

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 to 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 assquamous 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. Melanoma 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 it?

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 melanoma 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, 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 risk of melanoma increases if someone in the family has had melanoma, with gene mutations being passed from one generation to the next.

If melanoma 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.

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.

Know your ABCDEs

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.

The Melanoma Research Foundation provides a handy overview of the method you can reference when performing skin checks:

A - Asymmetrical Shape

Melanoma lesions are often irregular, or not symmetrical, in shape. Benign moles are usually symmetrical.

B - Border

Typically, non-cancerous moles have smooth, even borders. Melanoma lesions usually have irregular borders that are difficult to define.

C - Color

The presence of more than one color (blue, black, brown, tan, etc.) or the uneven distribution of color can sometimes be a warning sign of melanoma. Benign moles are usually a single shade of brown or tan.

D - Diameter

Melanoma lesions are often greater than 6 millimeters in diameter (approximately the size of a pencil eraser).

E - Evolution

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.

If you notice one or more of these symptoms, contact a dermatologist immediately.

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. These weird skin abnormalities should be checked out — they could be melanoma symptoms.

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 colors or shades
·  is bigger than the size of a pencil eraser in diameter
·  has appeared recently (ie. when you are an adult)

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.

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.

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.

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

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.

Download the SkinVision app 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.