Skin Cancer Blog - South East Skin Clinic


What is Skin Cancer?

Skin cancer is the uncontrolled growth of abnormal skin cells. Nodular melanoma and squamous cell carcinoma may grow over weeks, whilst Basal Cell Carcinoma (BCC) takes months to visibly enlarge.

Skin cancer makes up to 80% of all newly diagnosed cancers in Australia.  Most skin cancer is one of:

  • Basal Cell Carcinoma (BCC)
  • Melanoma
  • Squamous Cell Carcinoma
  • Intraepidermal Carcinoma (IEC)

Biopsy is usually required to establish a diagnosis.

Early diagnosis leads to better outcomes & easier treatment. For example, some types of IEC & BCC may be treated with skin cancer cream or gel.

What Causes Skin Cancer?

No matter the type of skin cancer, most causes fall into one of two very broad categories:

  • Unrepaired DNA mutations caused by UV or solar damage; or
  • Genetic mutations.

Skin Cancers – The top Four

Getting to know the common skin cancers

Graphic of a melanoma


Melanoma is triggered when unrepaired DNA triggers mutations in skin cells.  These mutated cells multiply rapidly form tumors.  Exposure to ultraviolet light is the usual cause of the initial damage. Melanoma originates in the basal cell layer of the epidermis.  When recognized and treated early, melanoma is almost always curable. There are different types of melanoma. Some grow slowly and some grow rapidly. Some are brown whilst others are pink.

Graphic of a BCC

Basal Cell Carcinoma

Basal cell carcinoma (BCC) has a number of causes. BCC has both genetic and environmental causes.

Long-term exposure to the sun, or brief but intense exposure that results in sunburn,  can contribute to BCC. Those with fair skin and blue, green, or grey eyes have a higher risk.  When BCC appears in an area that has not been exposed to the sun, or in a very young person, other possible culprits can be exposure to arsenic, or radiation; complications in healing from a burn, or a wound; or even an infection, vaccination, or tattoo. Australian guidelines recommend 6 monthly skin checks for at least 2 years after the diagnosis of a BCC.

Graphic of an SCC (Skin Cancer)

Squamous Cell Carcinoma

SCC is the second most common form of skin cancer & is mostly caused by the cumulative effect of sun exposure on the skin.  SCC typically occur in areas exposed to sunlight. However, SCC can occur in the mucous membranes and genital areas as well.  The skin cancer is caused by uncontrolled growth of cells in the upper levels of the skin.  They can look scaly or take on the appearance of ulcer or a wart.

Intraepidermal carcinoma (IEC) is an SCC that is very superficial.

The ratio of BCC to SCC is 6:1 in Brisbane and 2:1 in North Queensland.

Graphic of a solar keratosis

Solar Keratosis

These are known as sunspots and are not a true skin cancer. Sunspots are considered precanceous.  The use of the word ‘solar’ in the name makes it clear that this skin damage is caused by ultraviolet (UV) light.  UV exposure in tanning beds can also cause this type of skin damage.  These lesions commonly form on places that are easily exposed to the sun such as the face, ears, and the backs of your hands. Sunspots are really very common in South East Queensland. The risk of a single sunspot turning into a skin cancer (SCC) is around 1%. However, sun spots tend to occur in large numbers.

Benign Skin Lesions.

‘Good’ in one way, annoying in others!

Benign Skin lesions may be a nuisance for one of three reasons:

  • Catch on clothing, itch or even bleed. Skin tags are commonly to blame.
  • Be cosmetically unwanted. Seborrhoeic Keratosis is the most common culprit.
  • Have a likeness with a skin cancer. Many people attending a skin cancer clinic regularly have had a biopsy at some stage.
Graphic of seborrhoeic keratosis

Seborrhoeic Keratosis

Seborrhoeic Keratosis are known affectionately as ‘barnacles’ and are the bane of many Sun-loving Queenslanders. Simply known as a ‘Seb K,’ they are really common as we get older! They start to appear after the age of 30, with most people in their 40’s having at least one.  The lucky person has one or two whilst those with genetic tendency can have hundreds. Their appearance can vary tremendously. Colours vary from pink, red, brown or purple. They may be flat or raised. Their size varies from 0.2cm to 2cm in diameter. The telltale signs are their well-defined edge and waxy ‘stuck on’ surface. Dermatoscopy is very helpful indeed to confirm a Seb K and not melanoma, viral wart or SCC. Seb K’s  can be removed because of cosmetic reasons, catching on clothing, or to exclude skin cancer.

Graphic of a mole


Moles, also called ‘Nevi,’ are harmless growths. We all get them. Most adults have 12 to 20 moles. Some appear at or shortly after birth whilst others develop in childhood. The peak time for them appearing is adolescence. Fewer moles appear in adults. The development of a new mole after the age 40 is a ‘red flag’ and such a mole should always be checked carefully examined by a doctor. Moles may become both larger and darker during puberty or pregnancy. Melanoma may develop from a mole or develop spontaneously.

Graphic of a skin tag

Skin Tag

Skin tags are those fleshy tags of skin that we either love or hate – usually the latter! Like Seb K’s, they usually start developing after the age of 30. One quarter of adults have at least one skin tag. They are most commonly found under the arms, on the neck, or in the groin, and under the breasts in women. Skin tags may be hereditary, and are linked to being overweight. Skin tags are usually easy to identify. The telltale sign is a mobile, soft, skin-coloured tag that is attached to the skin with a ‘stalk.’ Skin tags often rub against clothing and may become sore or inflamed. They are easily removed.

Graphic of an age spot (solar lentigo)

Age Spot / Solar Lentigo

Solar lentigo may be referred to as an ‘Age Spot’ with around 75% of white people over 60 having at least one of them. Past exposure to UV light is in fact the main risk factor. Therefore, the typical distribution is the face, neck, forearms and backs of the hands.  ‘Sun freckles’ is a more accurate – and certainly kinder – pseudonym. Solar Lentigo are usually east to identify, being  flat, light brown in colour, and well defined on the surrounding paler skin. Their size varies from 2 to 20mm in diameter. Solar Lentigo may occasionally look like a skin cancer, particularly melanoma or IEC.

Author: Dr Richard Beatty

Last Modified:    27/9/2019

First published:  28/08/2014