What is melanoma?

Melanoma is a serious form of cancer that arises when the pigment-producing cells in the skin (melanocytes), start to grow out of control. The initial visible signs may display as a mole or lesion that grows, changes shape, or colour.

A dermatologist examines a mole of a patient

What is melanoma skin cancer? (and why have I got it?)

If you’ve recently been diagnosed with melanoma skin cancer, you may be wondering how this has happened, or why it has happened to you. In this informative and straightforward video, Dr Elaine Vickers explains how melanoma skin cancer occurs to help you better understand your diagnosis. This video also explains how melanoma differs from basal cell carcinoma and squamous cell carcinoma.

Melanoma facts and figures

How common is melanoma?

  • Melanoma is the UK’s most rapidly-increasing type of cancer, with around 16,700 new cases every year*
  • Melanoma is in the top 5 most commonly diagnosed cancers in the UK*, **
  • In contrast to most cancer types, melanoma occurs relatively frequently at younger ages, from 15 upwards
  • Melanoma is the second and third most common cancer in males and females respectively, between 15-44 years of age in England
  • Recent figures indicate that 2,333 people die each year from malignant melanoma in the UK*
  • Men typically have a higher lifetime risk (1 in 36) of developing melanoma, than women (1 in 47)*

* Cancer Research UK stats – Date ranges 2013 -2018. See references
** Cancer registration statistics, England: final release, 2018.
Published 29 May 2020.

Crowd of people

86% of melanomas are preventable (CRUK)


What causes melanoma?

Excess exposure to ultraviolet radiation, which comes from the sun, or sun beds, has been identified by researchers as the primary risk factor for developing melanoma. The back, head and neck or legs are the common locations for a lesion.

In addition, an individual’s likelihood of developing melanoma can also be influenced by many other factors, including:

  • Family history of melanoma
  • Certain genetic mutations
  • Skin pigment type (typically individuals with red hair colouration, fairer skin, or skin that burns and never tans are at higher risk)
  • Frequent sun burn
  • Increasing age (75+) that reflects accumulation of DNA damage
  • The presence of numerous moles or freckles
  • Autoimmune diseases like inflammatory bowel diseases (IBD)
  • Human Immunodeficiency Virus (HIV) can increase your chances of melanoma by 50%


What are the signs and symptoms of melanoma?

The two most common signs of melanoma skin cancer are:

  • The appearance of a new mole or lesion on your body
  • A change in an existing mole or lesion (such as a change in shape, bleeding or itching).

If you have an early-stage melanoma (stage 1 or 2 melanoma), you are unlikely to feel unwell or have any additional symptoms other than the appearance of your mole or lesion.  Contact your GP if you notice any changes or new lesions as most melanomas can be cured if caught at an early stage. If diagnosed with a later stage melanoma (stage 3 or 4) you may experience other symptoms.

Melanoma examples

What are the types of melanoma?

There are several types of melanoma. These include skin or cutaneous superficial spreading melanoma – which is the most common form in the UK. Other forms of melanoma include nodular, lentigo maligna, amelanotic, acral lentiginous melanoma and rare melanomas such as uveal (eye) and mucosal melanomas.