Recognising Melanoma


Published: 18 August 2020

I present in shades of pigment – from black, to skin-toned. My size ranges from millimetres to centimetres. Flat and masquerading as a freckle, or raised and mole-like, I may be completely symptomless. I am a melanoma.

While melanoma is a serious and potentially life-threatening type of skin cancer, it can be effectively treated if addressed quickly enough (MIA 2014).

For this reason, being able to detect and treat melanoma early is crucial - especially in Australia and New Zealand, where melanoma rates are the highest in the world (CCV 2018).

Melanomas have several features distinguishing them from BCC and cSCC. Awareness of these differences can assist with timely referral and treatment, thereby reducing morbidity associated with aggressive tumours and enhancing overall patient outcomes. All healthcare professionals should be able to identify lesions and refer appropriately.

What is Melanoma?

Melanoma is the third most common type of skin cancer after basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) (CCV 2018).

Due to its ability to grow and spread quickly - with the potential to become life-threatening in as little as six weeks - it is considered the most serious type of skin cancer (SunSmart 2018).

If untreated, melanomas can spread rapidly to other areas of the body including the lungs, brain, liver or bones through the lymphatic system or bloodstream (MIA 2014).

How do Melanomas Develop?

melanoma diagram
Melanoma is triggered by DNA mutation to the melanocyte cells.

Melanoma is triggered by DNA mutation (caused by UV radiation, usually from the sun) to the melanocyte cells, which sit between the basal cells in the epidermis (Skin Cancer Foundation 2019; CCV 2018).

Melanocytes help to protect the skin by producing melanin (pigment) upon exposure to UV radiation. In some cases, melanocytes cluster together during this process and form nevi (moles). However, DNA damage from burning or tanning can cause the melanocytes to mutate and grow in an uncontrolled way (MIA 2014; Skin Cancer Foundation 2019).

It is possible for a previously benign mole to develop into a melanoma, but only 30% of melanomas occur in this way. It is more common for melanomas to appear as completely new lesions (Pampena et al. 2017).

Melanomas usually develop in areas that are frequently exposed to UV radiation, such as the face, back, arms and legs, but they can appear anywhere on the body. This includes areas like the soles of the feet, the genitals, the nails and the inside of the mouth and eyes that receive very little UV exposure (Mayo Clinic 2020; MIA 2014; CCA 2017).

Warning Signs for Melanoma

Melanomas can be a variety of sizes, shapes and colours. In most cases, they present as new and unusual-looking lesions. They may be several millimetres or centimetres in diameter, depending on how much they have grown. Common characteristics include an uneven or smudgy outline, blotchiness and a flat or slightly raised surface. Existing moles that develop into melanomas will often change in colour, size or shape (SunSmart 2018; Oakley 2015).

Possible colours include brown, black, blue, red and grey, or several of these colours within the one lesion. Some melanomas may be amelanotic, meaning they lack pigment (Oakley 2015).

They may be itchy or tender, and some crust or bleed (Oakley 2015).

Types of Melanoma

Type Prevalence Location Common physical characteristics Growth and spread rate Image
Superficial spreading melanoma
  • 50-60% of melanomas
  • More common in younger people
  • Can appear anywhere on the body
  • Can be a new lesion or change to an existing mole or freckle
    • Flat or slightly raised
    • Asymmetrical patch with uneven borders
    • Tan, brown, black, red, pink, blue or white in colour
    • Can be amelanotic
    Grows slowly, but can be dangerous if it progresses
    Nodular melanoma
    • 10-15% of melanomas
    • More common in older adults
    Usually found on the head and neck Raised, round nodule on the surface of the skin Fast-growing and aggressive

    'Photography of nodular melanoma' by DermNetNZ is licensed under CC BY 4.0

    Lentigo maligna melanoma
    • 10-15% of melanomas
    • More common in older adults
    Usually appears on the face, ears, head and neck
    • Resembles a large freckle
    • Black or brown
    • Flat or slightly raised
    • Blotchy
    Grows slowly and close to the surface of the skin

    'Lentigo maligna melanoma on the left cheek' by Omar Bari & Philip R. Cohen is licensed under CC BY 3.0

    Acral lentiginous melanoma
    • 1-2% of melanomas
    • The type of melanoma that is most likely to affect people of colour
    Usually appears in ‘hidden’ areas including under the nails, on the soles of feet and on the palms of hands
    • Colourless or lightly pigmented area
    • May be mistaken for a stain or bruise
    Grows slowly before becoming invasive

    'Photography of a large acral lentiginous melanoma' by Xavier-Júnior; José & Munhoz; Tania & Souza; Vinicius & Campos; Eloísa & Stolf; Hamilton & Marques; Mariângela is licensed under CC BY 4.0

    Desmoplastic melanoma 1% of melanomas Usually appears on the head or neck
    • Firm, skin-coloured lump
    • May be scar-like
    • May have a patch of overlying pigmentation
    • Becomes more distinctive over time
    Grows and changes over time

    (CCV 2019; Skin Cancer Foundation 2019; Oakley 2017)

    Prevalence of Melanoma

    In 2020, melanoma is estimated to affect at least 16 000 Australians and cause over 1300 deaths (Cancer Australia 2020).

    As a comparison, cSCC and BCC combined account for about 777 000 cancer cases and 560 deaths each year (CCV 2018; CCA 2019).

    It is estimated that about 1 in 14 men and 1 in 21 women will develop melanoma before the age of 85. While the average age of diagnosis is about 60, people of any age can develop melanoma, with those under 40 making up about 9.2% of cases (CCA 2020).

    Risk Factors for Melanoma

    • Older age;
    • Fair complexion (particularly if the individual has freckles, blonde or red hair or blue or green eyes);
    • Lots of moles (more than 10 above the elbow on the arms and more than 100 on the body), especially if they are irregular or uneven;
    • History of skin cancer (melanoma or another type);
    • Strong family history of melanoma;
    • Unprotected UV exposure (either from the sun or artificial sources);
    • Short, intense periods of UV exposure;
    • History of sunburns or tanning;
    • Reduced immune function due to illness or immunosuppressive medications; and
    • Parkinson’s disease.

    (CCV 2019; Oakley 2015)

    Diagnosis and Treatment of Melanoma

    skin check for melanoma

    ABCDE Guidelines

    The ABCDE guidelines can be used to assess a lesion for possible melanoma.

    A: Asymmetry One half of the lesion is different from the other.
    B: Border irregularity The edges of the lesion are irregular, ragged, notched, or blurred.
    C: Colour variation There are several different colours within the lesion that may be unevenly or irregularly distributed.
    D: Diameter The lesion is larger than 6mm in diameter or is noticeably growing.
    E: Evolving The lesion is changing in size, shape, colour or elevation, or is itching, bleeding or crusting.

    (MIA n.d.; Jin 2019)

    If melanoma is suspected, the patient will generally undergo a biopsy (either partial or excisional) and the skin sample will be sent for a pathological assessment (MPA 2017).

    Melanoma Staging and Treatment

    Stage Description Main treatment options
    Stage 0 (in situ)
    • Melanoma is confined to the epidermis
    • No evidence of spread to lymph nodes or metastasis
    • Surgical excision
    Stage I
    • Melanoma is up to 2 mm thick
    • No evidence of spread to lymph nodes or metastasis
    • Ulceration may be present
    • Surgical excision
    • Removal of nearby lymph nodes may be considered
    Stage II
    • Melanoma is either:
      • Greater than 1 mm thick and ulcerated; or
      • Greater than 2 mm thick, with or without ulceration
    • No evidence of spread to lymph nodes or metastasis
    • Surgical excision
    • Removal of nearby lymph nodes
    • Radiation or treatment
    Stage III
    • Evidence of spread to lymph nodes
    • No evidence of metastasis
    • Removal of lymph nodes
    • Radiation or treatment
    Stage IV
    • Evidence of metastasis
    • Systematic drug therapies (e.g. immunotherapy, targeted therapy)
    • Surgical excision
    • Radiation

    (MPA 2019; CC NSW 2019; MIA 2014)


    While melanomas can usually be resolved through excision if caught early enough, untreated melanomas can quickly become complicated and life-threatening.

    Therefore, being able to identify and respond to suspect lesions as soon as possible is crucial.

    Additional Resources


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