Causes and Risk Factors of Nodular Melanoma

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Nodular melanoma, like other melanomas, is believed to be caused by a mutation in skin cells. These mutations may be triggered by a number of factors, and it is believed exposure to ultraviolet (UV) light plays a major role.

Other risk factors for nodular melanoma include genetics, lifestyle factors like tanning, having a weakened immune system, having a lot of moles, or having a family history of melanoma.

Learn more about the causes and risk factors of nodular melanoma.

Common Causes

Nodular melanoma is caused by a mutation in a kind of skin cell called melanocytes. These cells are responsible for giving skin pigment, and they influence the color of hair as well.

A number of risk factors can trigger these mutations.

Exposure to UV Light

Ultraviolet light can damage a skin cell’s DNA, triggering mutations that can lead to skin cancer.

The immune system works to repair some of the damage to DNA from UV light, but can’t fix everything. Over a period of time, the damaged DNA can then cause mutations, leading to skin cancers like melanoma.

UV can be found in sunlight. Sunlight contains three different types of UV light:

  • Ultraviolet A (UVA)
  • Ultraviolet B (UVB)
  • Ultraviolet C (UVC)

UVA, UVB, and UVC can all cause damage to the skin. UVC is considered the most dangerous form of ultraviolet light, but the earth’s atmosphere filters this out.

It is believed UVB light is the main contributor to skin cancer, but the role of UVA in causing melanoma is yet to be determined. Over time, both UVA and UVB light can damage skin and increase the risk of skin cancer.

Experiencing frequent sunburn increases the risk of developing any type of melanoma, while UV light exposure from other sources like tanning beds can also increase the risk of nodular melanoma.


Genes are thought to play a role in the development of melanoma, including nodular melanoma.

Certain genes (called tumor suppressor genes) are tasked with fixing mistakes in DNA, which helps keep the growth of cells under control and ensures cells die at the right moment. This helps prevent the growth of tumors or cancerous lesions.

Genetic Risk Factors for Nodular Melanoma

Verywell / Laura Porter

However, genetic mutations can cause tumor suppressor genes to be turned off. This can lead to cells growing out of control and can cause cancer like melanoma.

Gene mutations can either be acquired or inherited.

Acquired Gene Mutations

In the majority of cases, mutations of genes that are associated with nodular melanoma happen during a person’s lifetime and aren’t inherited from their parents.

Sometimes, these acquired genetic mutations can seemingly happen randomly, with no apparent cause. They can also be due to lifestyle factors, like exposure to UV light.

In some cases, melanoma might appear in a part of the body that rarely gets exposed to UV light. These kinds of melanoma might have different genetic mutations than those that have seen regular exposure to sunlight.

Typically, nodular melanoma is associated with mutations in the BRAF and NRAS genes. In one recent study, mutations were found in 64% of melanomas overall, and mutations were more frequent in nodular melanomas.

Inherited Gene Mutations

Though less common, people can inherit genetic mutations from their parents, which can raise the risk of melanoma.

Melanomas that are familial or inherited are typically linked to genetic mutations of the tumor suppressor genes. Mutations to genes like CDKN2A and CDK4 can stop these genes from controlling the growth of cells, leading to the development of cancerous growths.

In some cases, people can inherit a genetic mutation that causes changes to XP (ERCC) genes that have the job of repairing DNA that is damaged within a cell. If these genes have a mutation, cells can have difficulty repairing the damage done to DNA by UV light.

People with these genetic mutations may be more likely to develop nodular melanoma.

Other Genetic Risk Factors

A number of genetic factors can lead to the development of melanoma.

Melanoma can run in families, with roughly one in 10 of every person with melanoma having a family member with a history of melanoma.

Those who have a first-degree relative with melanoma are at greater chance of themselves developing melanoma. In other words, if one or more close biological relatives like a sibling, parent, or child has melanoma, those in the same close biological family are at an increased risk of melanoma.

Anyone of any skin color can get melanoma, but certain people are at an increased risk, including those with:

  • Fair skin
  • Red hair
  • Blonde hair
  • Green eyes
  • Blue eyes
  • Skin that freckles easily
  • Skin that burns easily

Lifestyle Risk Factors

Certain lifestyle factors can increase the risk of developing melanoma. These factors are related to exposure to UV light.


Tanning either outside in the sun or indoors in a tanning bed can increase the risk of nodular melanoma and other skin cancers.

The “glow” seen in a tan is not an indication of health; it is actually a visual sign of damage to skin cells and injury to DNA.

Not only does tanning increase the risk of nodular melanoma, but it also increases the risk of basal cell carcinoma and squamous cell carcinoma.

When a person tans, the ultraviolet radiation from either the sun or a tanning bed causes damage to the cells found in the outermost layers of skin. In an attempt to prevent further injury to the cells, the skin produces a pigment called melanin that gives color to the skin. This causes the skin to darken, creating a tan.

The damage is cumulative, and every time a person tans, the damage builds, triggering more genetic mutations and increasing the risk of cancer.


Exposure to ultraviolet radiation causes an inflammatory reaction to the skin’s outermost layers, called sunburn.

Those who have less melanin, a pigment that colors the skin to try and protect it from the sun, burn more easily. If they are exposed to the sun and their skin is unprotected, this causes the cells in the skin to swell and become red and painful, giving the visual appearance of sunburn.

Like tanning, sunburn is a visual sign of damage to the skin cells.

Damage to the skin has a cumulative effect from the very first sunburn. Getting sunburnt repeatedly raises the risk of nodular melanoma.

It’s important to note that damage from UV rays can happen even if there are no obvious visual signs of sunburn.

Other Risk Factors

A number of other risk factors may contribute to the development of melanoma. These include:

  • Moles: Having a lot of moles or having atypical moles increases the risk of nodular melanoma.
  • A weakened immune system: Those who are immunocompromised are more likely to develop skin cancer, including nodular melanoma.
  • Age: Nodular melanoma is more likely to occur in older people, but it is still possible in younger people, especially young women. Melanoma that runs in families can still occur at any age.
  • Sex: In the United States, men have higher rates of all types of melanoma than women after age 50. Women have a higher risk before age 50.

A Word From Verywell

Nodular melanoma, like other forms of melanoma, is believed to be caused by mutations in skin cells. A number of risk factors can cause these mutations, including exposure to UV rays, inherited genetic mutations, and lifestyle factors. Other risk factors include sex, age, and a weakened immune system.

The most important thing you can do to reduce your risk of developing nodular melanoma and other forms of skin cancer is to reduce your exposure to the sun’s UV rays by wearing sunscreen and avoiding tanning or getting sunburnt.

If you are concerned about your risk of developing skin cancer, speak with your healthcare provider about other measures you can take.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  9. Skin Cancer Foundation. Sunburn & your skin. Updated June 2019.