How Cancerous Moles Differ from Normal Moles

How Cancerous Moles Differ from Normal Moles

Moles are unpleasant spots that nobody likes to see on their skin. However, there are times when a mole might not be just a vain issue and may indicate a higher risk of skin cancer. 

Learning to tell the difference between the two is not an easy task but fortunately, majority of the moles people have does not develop into melanoma or skin cancer.

What is melanoma?

It is one of the most dangerous forms of skin cancer. It begins in the innermost layer of the skin (epidermis) and occurs when cells start behaving abnormally. 

Melanoma can occur anywhere on the body developing from existing moles or start as a new growth. If left untreated, it can spread to other parts of the body including organs.

Are malignant moles common?

Only a small percentage of moles are at risk of turning into melanoma. According to World Health Organization, about 132,000 melanoma skin cancers are reported every year. Although it’s just 1 percent of the overall skin cancer cases, this lethal disease is responsible for the majority of skin cancer deaths.

While a skin expert or dermatologist is the only one who can help you know actual situation, there are few things you can figure out yourself if you see something weird is happening.

Typical characteristics of abnormal moles

Generally, for many years doctors and experts have preached the rule of ABCDE to differentiate between a normal and malignant mole. These are just general signs.

A-Asymmetrical - In most cases, melanoma lesions are irregular in shape not symmetrical. If you draw a line in between a normal mole, the two will look like mirror images.

B-Border - The border of a normal mole is typically smooth, even and not blurry, unlike melanoma.

C-Color - The presence of multiple colored (red, white, blue, black) moles can be a warning sign of melanoma. 

Normal moles are uniform in color, usually a single shade of brown.

D-Diameter - Abnormal cancerous moles are often greater than 1/4inch or 6mm, as big a diameter of a pencil.

E-Evolution - Evolution can refer to any change in the shape. Moles generally do not change. If a mole goes through quick changes in color or size, it could be a sign of melanoma. 

In recent years, evolution has become the most important factor in diagnosing melanoma.

What causes Melanoma?

Experts are yet to decipher the exact causes but typically, melanomas occur due to gene mutation and one of the factors of gene changes is exposure to sunlight which is a great source of radiation. Some studies even relate 95 percent of skin cancer to ultraviolet radiation.

Who are at risk?

  • People with fair skin are at risk as they have less skin pigment known as melanin
  • Prone to sunburn or history of sunburn
  • Family history of melanoma
  • Weak immune system

Is there any cure for melanoma?

There are basically five stages ranging from 0 to 4. Each defines the progression of the disease. Treatment involves a single mole removal to the radiation therapy depending on the stage.

Melanoma Prevention

The best way to prevent the disease is to limit the exposure to sun and application of sunscreen. Apart from self-checking, it is important to go through regular body checks and tell the doctor if you spot anything unusual.


1. Skin cancers(n.d.). WHO read more
2. Common Moles, Dysplastic Nevi, and Risk of Melanoma(2017, May 3). National Cancer Institute read more
3. How to Spot an Atypical Mole(n.d.). Skin Cancer Org read more
4. Melanoma Skin Cancer(2016). American Cancer Society read more
5. Skin cancer (melanoma)(2017,January 05). NHS 
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