Published: 18 August 2020
Published: 18 August 2020
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.
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).
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).
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).
|Type||Prevalence||Location||Common physical characteristics||Growth and spread rate||Image|
|Superficial spreading melanoma||
||Grows slowly, but can be dangerous if it progresses|
||Usually found on the head and neck||Raised, round nodule on the surface of the skin||Fast-growing and aggressive|
|Lentigo maligna melanoma||
||Usually appears on the face, ears, head and neck||
||Grows slowly and close to the surface of the skin|
|Acral lentiginous melanoma||
||Usually appears in ‘hidden’ areas including under the nails, on the soles of feet and on the palms of hands||
||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||
||Grows and changes over time|
(CCV 2019; Skin Cancer Foundation 2019; Oakley 2017)
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).
(CCV 2019; Oakley 2015)
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).
|Stage||Description||Main treatment options|
|Stage 0 (in situ)||
(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.
Question 1 of 1
True or false? Most melanomas appear as changes to existing moles.
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