Skin Cancer Explained

Types of skin cancer

Learn more about the three main skin cancer types – melanoma, basal cell carcinoma, and squamous cell carcinoma.
MoleMap Team
March 1, 2024
10 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 the earlier it’s found, the easier it is to 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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What is skin cancer?

Skin cancer is a disease that occurs when your skin cells grow abnormally, usually caused by too much exposure to ultraviolet (UV) radiation from the sun or sunbeds.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.

What are the 3 skin cancer types?

There are three main different types of skin cancer – which are named according to the cells in which they form. Melanoma is the fastest growing and most dangerous form of skin cancer. Basal cell carcinoma and squamous cell carcinoma (also known as ‘non-melanoma’ skin cancer or ‘keratinocyte’ cancers) are more common but usually aren’t life-threatening. 

Read on to learn more about these 3 types of skin cancer, with pictures, to help you recognise the early signs of skin cancer.

Illustration of the different types of cells that lead to the various types of skin cancer.
There are three main different types of skin cancer: Melanoma the fastest growing and most dangerous, basal cell carcinoma and squamous cell carcinoma, which are more common but usually not life-threatening.

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Melanoma grows from melanocytes — these are the 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). However, it’s considered the most serious because it can spread to other parts of the body very quickly (AKA metastasise). 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%5 - which is why it’s vital to detect melanoma early.

What are the signs of melanoma?

There are a few different 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 ABCDEFG rule is a handy guide for self-checking your skin. It outlines the seven signs of skin cancer not to be missed.  It’s a good idea to get to know them so you can recognise the early signs of melanoma. If you notice any variations to your moles, such as a change in size, shape, or colour, it could suggest a melanoma may be developing.

If you think you have any melanoma symptoms, we recommend booking a Full Body Mole Check (our most comprehensive service) as soon as possible.

Images of different looking melanomas.
As these images show, melanoma can come in many different forms. If you spot any of the above signs, see your doctor or book with MoleMap as soon as possible.

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. 

Skin cancer treatment 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 in this guide to melanoma.

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 in the lower layer of cells of the epidermis (the outer, top layer of 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 skin 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. Hence, the importance of being sun smart. 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 – if 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 Check for a professional diagnosis.

Images of basal cell carcinomas.
Basal cell carcinoma is the least deadly of the three main types of skin cancer. But, like melanoma, it can present itself in different forms.

Diagnosis and treatment of basal cell carcinoma

Like all forms 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 of the various types of skin cancer. It accounts 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 of skin cancer.

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? Find a MoleMap clinics location near you for a skin cancer check.

Image of squamous cell carcinomas.
Squamous cell carcinoma is the second most common of the types of skin cancer. It’s usually not life threatening, but it can spread if left untreated.

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 skin cancer treatments are available these days, including excision, cryosurgery, photodynamic therapy, 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 cancers

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 skin cancer, book a mole check for a professional diagnosis, or talk to your doctor.

Images of solar keratosis.
The early signs of solar keratosis, Bowenoid keratosis and SCC in-situ – if you think you may have any of these symptoms, see your doctor or book an expert skin exam.

What’s your skin cancer risk?

Skin cancer risk depends 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’).
  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. Keep reading to find out how to lower your risk of developing skin cancer.  And don't forget the importance of adequate vitamin B3 and vitamin D intake!

How to reduce your skin cancer risk?

It’s essential to always protect your skin when outdoors – even if it’s just for a few minutes. Avoid the sun during the middle of the day (when the UV Index is at its highest) and cover up with a broad-spectrum SPF50+ sunscreen or sunblock, loose clothing, a broad-brimmed or UPF 50+ sun hat and sunglasses when you’re out and about.

Lady wearing a wide-brim sun hat and sunglasses at the park.
It’s essential to always protect your skin when outdoors – even if it’s just for a few minutes.

Get into the habit of self-checking your skin regularly – every three months, especially if you’re moderate to high risk. Get to know your skin like the back of your hand (literally!). 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 the different 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 now at MoleMap, an Australia skin cancer clinic, as soon as possible.


1. Health Direct Australia:


4,5 New Zealand Skin Cancer Primary Prevention and Early Detection Strategy 2017 to 2022. Health Promotion Agency and the Melanoma Network of New Zealand. 2020. Available from: (Accessed Jan, 2020). Balch CM, Gershenwald JE, Soong S, et al. Final version of 2009 AJCC Melanoma Staging and Classification. JCO 2009;27:6199–206.


8,9. Cancer Council of Australia:

10. Dermet NZ:

11,12. Cancer Council of Australia

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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