Skin Cancer Explained

Types of skin cancer

Learn more about the three main skin cancer types – melanoma, squamous cell carcinoma and basal cell carcinoma.
MoleMap Team
August 14, 2023
15 minutes

Skin can­cer is the most com­mon type of can­cer in Aus­tralia: every year, more than 13,000 Aussies are diag­nosed with melanoma — and around 980,000 new cas­es of non-melanoma skin can­cers are treat­ed.1

Skin can­cer is most­ly pre­ventable – and as an exter­nal can­cer, lends itself to visu­al diag­no­sis at a much ear­li­er stage than oth­er cancers.

The ear­li­er skin can­cer is found, the eas­i­er it is to suc­cess­ful­ly treat.2 This arti­cle out­lines the three main types of skin can­cer – the symp­toms, diag­no­sis process, and treat­ments avail­able – and how you can reduce your risk of get­ting any form of skin can­cer in the first place.

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First­ly, what is skin cancer?

Skin can­cer is a dis­ease that occurs when your skin cells grow abnor­mal­ly. This is usu­al­ly due to ultra­vi­o­let (UV) radi­a­tion from the sun or sunbeds2, or in some cas­es, due to inher­it­ed genet­ic fac­tors 3.

This uncon­trolled growth of abnor­mal cells forms a tumour in the skin. Many skin lesions are benign (non-can­cer­ous), but unfor­tu­nate­ly some are malig­nant (can­cer­ous), this means the tumour consists of malignant cells with the potential to spread to oth­er parts of the body…and become life-threatening.

The 3 main skin can­cer types

There are three main types of skin can­cer – which are named accord­ing to the cells in which they form.

Melanoma is the fastest-grow­ing and most dan­ger­ous kind of skin can­cer, while basal cell car­ci­no­ma and squa­mous cell car­ci­no­ma (also known as​‘non-melanoma’ or​‘ker­atinocyte’ can­cers) are more com­mon but usu­al­ly less life-threatening.

Basal cell and squa­mous cell car­ci­no­mas often grow local­ly, and they can affect almost any part of the body. Most of the time they appear on the body parts that are nor­mal­ly exposed to the sun.

Melanoma is the more severe as it can spread at a much ear­li­er stage.

3 types of skin cancer — 3D model

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Types of skin can­cer – pictures

Unlike most can­cers, skin can­cer can usu­al­ly be ​‘seen’ on the top lay­er of the skin – mak­ing it eas­i­er to detect and treat it early.

To get a gen­er­al idea of what skin can­cer can look like, it can be help­ful to look at pho­tos. There are many images and pho­tos of skin can­cers avail­able online; this gallery from the Skin Can­cer Foun­da­tion is just one example.

But it’s impor­tant that you do not try to make a self-diag­no­sis this way. You could have some­thing on your skin that ​‘doesn’t look like any of the pic­tures’ – but it’s still skin can­cer. Skin can­cers can look very dif­fer­ent from per­son to person.

The only way to diag­nose it prop­er­ly is to get your skin checked by a qual­i­fied skin can­cer expert.

Read on to learn more about the three main skin can­cer types.


Melanoma grows from cells called melanocytes — cells that give your skin its colour. It’s the least com­mon of the three main forms of skin can­cer (account­ing for only one to two per cent of cas­es) but it’s con­sid­ered the most seri­ous because it can spread (metas­ta­sise) through­out the body very quick­ly – and once it pen­e­trates below the sur­face of the skin it can soon become deadly.

Sur­vival rate is large­ly depen­dent on the thick­ness (depth) of melanoma – in gen­er­al, the thin­ner the lesion, the bet­ter the out­come. For exam­ple, a per­son diag­nosed with a melanoma less than 1mm thick can expect to have a 92% ten-year sur­vival rate.4

How­ev­er, if it’s not detect­ed until it’s greater than 4mm thick, the ten-year sur­vival rate reduces to 50% — which is why it’s so vital to detect melanoma ear­ly. Find out more about how to spot the ear­ly signs of melanoma.

What are the signs of melanoma?

There are four main types of melanoma, includ­ing nodu­lar melanoma, which is par­tic­u­lar­ly dan­ger­ous as it grows very fast and needs ear­ly diag­no­sis and removal. The most obvi­ous warn­ing signs are any changes to your moles or spots, or any new moles that appear suddenly.

The ABCDE and EFG rules are handy guides for self-check­ing your skin – it’s a good idea to get to know them so you can recog­nise the ear­ly signs of melanoma. If you notice any vari­a­tions such as a change in size, shape or colour, it could sug­gest a melanoma may be developing.

Anoth­er use­ful acronym is SCAN – which stands for sore, chang­ing, abnor­mal or new. Find out more at scanyourskin.

And if you think you have any melanoma symp­toms, we rec­om­mend book­ing a Full Body MoleMap (our most com­pre­hen­sive ser­vice).

Types of skin cancer — Melanoma

How is melanoma diag­nosed and treated?

If melanoma is sus­pect­ed, a biop­sy of the lesion (mole or spot) will be tak­en and any near­by lymph nodes will also be checked. The sam­ples are then sent for test­ing to con­firm whether the lesion is a melanoma.

Melanomas are grad­ed accord­ing to how far they have spread through­out the body:

  • Stage 0‑II refers to ear­ly melanoma (usu­al­ly treat­able with removal of the mole and sur­round­ing skin).
  • Stage III melanoma (region­al) has spread to near­by lymph nodes, skin or tissues.
  • Stage IV melanoma (advanced or metasta­t­ic) means the can­cer has spread to oth­er parts of the body.

Treat­ments for Stages III and IV melanoma may include chemother­a­py, radi­a­tion ther­a­py or tar­get­ed ther­a­pies (which mod­i­fy the actions of spe­cif­ic genes) and immunother­a­pies (which mod­i­fy the actions of the immune sys­tem). You can read more about treat­ment options here.

Basal cell carcinoma

Basal cell car­ci­no­ma (BCC) is the most com­mon form of skin can­cer in the world, account­ing for about 70% of non-melanoma skin can­cers. BCC begins in basal cells, which are locat­ed in low­er lay­er of cells of the epi­der­mis (the top, out­er lay­er of the skin). This type of skin can­cer tends to grow slow­ly, and rarely spreads to oth­er parts of the body.

BCCs can appear any­where on the body but most com­mon­ly devel­ops on parts of the body that receive high or inter­mit­tent sun expo­sure (head, face, neck, arms, shoul­ders and back).8 They often appear as a change in the skin, such as a growth or a sore that doesn’t heal. Basal cell car­ci­no­ma is par­tic­u­lar­ly com­mon in old­er males, but it can also affect females and younger adults.9

Long-term sun dam­age is a risk fac­tor, and so is repeat­ed sun­burn or sunbed use. Hav­ing fair skin increas­es your risk, although it can also affect those with dark­er skin too.

While BCC is very com­mon, par­tic­u­lar­ly in coun­tries like Aus­tralia and New Zealand, very few peo­ple die from it as it’s usu­al­ly treat­able – as long as it’s detect­ed ear­ly. How­ev­er, a tiny pro­por­tion of this type of skin can­cer can grow rapid­ly, invade deeply, and/​or metas­ta­sise to local lymph nodes.10

What are the signs of basal cell carcinoma?

Symp­toms of BCC may include:

  • waxy small raised lesions (papules) with a depressed centre
  • Ulcer-like appear­ance or pearl-like and translucent
  • A ten­den­cy to bleed
  • Red and scaly, ooz­ing or crust­ed areas
  • Raised bor­ders
  • Black-blue or brown areas

Basal cell car­ci­no­ma can vary in diam­e­ter from a few mil­lime­tres to sev­er­al cen­time­tres. Hav­ing one BCC increas­es the risk of get­ting anoth­er – it’s pos­si­ble to have more than one BCC at the same time on dif­fer­ent parts of the body.

If you’re con­cerned you might have a basal cell car­ci­no­ma, book a skin checks for a pro­fes­sion­al diagnosis.

Types of skin cancer — Basal cell carcinoma

Diag­no­sis and treat­ment of basal cell carcinoma

Like all kinds of skin can­cer, the ear­li­er a basal cell car­ci­no­ma is diag­nosed, the eas­i­er it is to treat. If left untreat­ed, it can grow deep­er into the skin and dam­age near­by tis­sue, mak­ing treat­ment more dif­fi­cult.11

The treat­ment for a BCC depends on its type, size and loca­tion, the num­ber to be treat­ed, patient fac­tors, and the pref­er­ence or exper­tise of the doc­tor. Most BCCs are treat­ed sur­gi­cal­ly. Reg­u­lar, long-term mon­i­tor­ing is rec­om­mend­ed to check for new and recur­ring lesions – and to catch them ear­ly when they’re eas­i­er to treat.

Squa­mous cell carcinoma

Squa­mous cell car­ci­no­ma (SCC) is the sec­ond most com­mon skin can­cer, account­ing for about 30% of non-melanoma skin can­cers.6

SCC devel­ops in the squa­mous cells (which make up the mid­dle and out­er lay­ers of the skin). It usu­al­ly appears where the skin has had the most sun expo­sure, such as the scalp, ears, lips or the backs of hands, but it can occur any­where on the body. It tends to grow quick­ly on the skin over sev­er­al weeks or months.

Squa­mous cell car­ci­no­ma is not usu­al­ly life threat­en­ing, but it can be more dan­ger­ous than basal cell car­ci­no­ma, because of its abil­i­ty to grow big­ger and/​or spread to oth­er parts of the body if left untreat­ed.7

This type of skin can­cer usu­al­ly results from pro­longed expo­sure to ultra­vi­o­let (UV) radi­a­tion, either from sun­light or from using sunbeds, so avoid­ing UV light helps reduce your risk.

What are the signs of squa­mous cell car­ci­no­ma?

When self-check­­ing your skin (or the skin of a loved one), look for:

  • A firm, red nodule
  • A flat sore with a scaly crust
  • A new sore or raised area on an old scar or ulcer
  • A rough, scaly patch on your lip that may evolve to an open sore
  • A red sore or rough patch inside your mouth
  • A red, raised patch or wart-like sore on or in the anus or on the genitals

Wor­ried you might have a squa­mous cell car­ci­no­ma? Book a skin check for a pro­fes­sion­al opinion.

Types of skin cancer — Squa­mous cell car­ci­no­ma

How is squa­mous cell car­ci­no­ma treated?

Treat­ment for SCC depends on the type, size, loca­tion and depth of the lesion, as well as your age and over­all health. A wide range of treat­ments is avail­able these days, includ­ing exci­sion, Mohs surgery, cryosurgery, elec­tro-surgery or laser surgery, radi­a­tion ther­a­py and top­i­cal med­ica­tions.8

Ask your der­ma­tol­o­gist or doc­tor to clear­ly explain the options that might work best for you, includ­ing details about the risks and benefits.

Oth­er types of skin cancer

Anoth­er less com­mon group of non-melanoma lesions are called​‘ker­atinocyte dys­plasias’. These include solar ker­ato­sis, Bowenoid ker­ato­sis and squa­mous cell car­ci­no­ma in-situ (Bowen’s disease).

While these are not inva­sive can­cers, they may require treat­ment as some can devel­op into non-melanoma skin can­cers. If you think you may have symp­toms of any of these skin can­cers, book a skin check for a pro­fes­sion­al diag­no­sis, or talk to your doctor.

book a skin check for a pro­fes­sion­al diag­no­sis

Know­ing your risk, can reduce your risk

We all have a dif­fer­ent lev­el of skin can­cer and melanoma risk, depend­ing on a range of fac­tors, such as our age, skin colour, fam­i­ly his­to­ry and lifestyle. The 7 most com­mon risk fac­tors include:

  1. You have fair skin, blue eyes and blond or red hair
  2. You have a lot of moles (more than 50)
  3. You have unusu­al-look­ing moles (the​‘ugly duck­ling rule’).
  4. You’re aged 50 or old­er – around 70% of melanoma cas­es occur in peo­ple aged 50 plus.11
  5. You have a fam­i­ly or per­son­al his­to­ry of melanoma or oth­er skin cancer.
  6. You’ve been sun­burnt — get­ting sun­burnt at any age increas­es the risk of all skin can­cers, includ­ing melanoma, in lat­er life.12
  7. You lead an out­door lifestyle and spend a lot of time in the sun.

Take this quick risk quiz to see whether you have a high, mod­er­ate or low risk of skin can­cer. And take steps to reduce your risk by get­ting to know the risk fac­tors of skin can­cer in more detail.

take steps to reduce your risk by get­ting to know the risk fac­tors of skin can­cer

How can you reduce your risk of all types of skin cancer?

First of all, always pro­tect your skin when you’re out­side – even if it’s just for a few min­utes. Stay out of the harsh­est sun­light in the mid­dle of the day (espe­cial­ly between 10am to 4pm in day­light sav­ings months) and cov­er up with a broad-spec­trum SPF30+ sun­screen, loose cloth­ing, a broad-brimmed hat and sun­glass­es when you’re out and about.

Get in the habit of self-check­ing your skin reg­u­lar­ly – at least every six months and more often if you’re mod­er­ate to high risk. Get to know your skin like the back of your hand (lit­er­al­ly!) and use a hand-held mir­ror to check all areas, freck­les and moles – or even bet­ter, get some­one to check those hard-to-reach spots for you.

And remem­ber, ear­ly detec­tion is your best pro­tec­tion against all types of skin can­cer. If you notice any changes or new spots, or a mole just doesn’t look or feel right, see your doc­tor or book an expert mole check or a skin check as soon as possible.

MoleMap Team

At MoleMap we check, detect and treat skin cancer. Find out how you can protect your skin at your nearest MoleMap skin cancer clinic.

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