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 enlarge visibly.

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)

A biopsy is usually required to establish a diagnosis.

Early diagnosis leads to better outcomes and 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 cases 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 develops when unrepaired DNA causes mutations in skin cells.  These mutated cells multiply rapidly to form tumours.  The initial damage is usually caused by exposure to ultraviolet light. 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 several 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.  If the BCC appears in an area that has not been exposed to sunlight or in a very young individual, other possible causes can include exposure to arsenic or radiation; complications from burns or wounds; or even 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 and is mostly caused by the cumulative effect of sun exposure on the skin.  SCC typically occur in areas exposed to sunlight. However, SCC can also occur on mucous membranes and in the genital area.  Skin cancer is caused by uncontrolled cell growth in the upper layers of the skin.  They can look scaly or take on the appearance of an ulcer or a wart.

Intraepidermal carcinoma (IEC) is a very superficial SCC.

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 precancerous.  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 in places that are easily exposed to the sun, such as the face, ears, and 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, sunspots 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:

  • They can catch on clothing, itch or even bleed. Skin tags are commonly to blame.
  • Be cosmetically unwanted. Seborrhoeic Keratosis is the most common cause.
  • Have a resemblance to skin cancer. Most people attending a skin cancer clinic regularly have undergone a biopsy at one point or another.
Graphic of seborrhoeic keratosis

Seborrhoeic Keratosis

Seborrhoeic Keratosis is 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.  Those with genetic tendencies have hundreds, while the lucky ones have one or two. 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 in confirming a Seb K over melanoma, viral warts, or SCC. Seb Ks may be removed for cosmetic reasons, catching on clothing, or to prevent skin cancer.

Graphic of a mole


Moles, also known as nevi, are harmless growths. We all get them. Adults typically have 12 to 20 moles. Some appear shortly after birth, while others develop during childhood. Adolescence is the peak time for them to appear. Adults are less likely to develop moles. The development of a new mole after the age of 40 is a ‘red flag’, and a doctor should carefully examine such a mole. 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 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 can be referred to as an age spot, with around 75% of white people older than 60 having one or more. Past exposure to UV light is the main risk factor. The typical distribution is, therefore, the face, neck, forearms, and back of the hands.  Sun freckles is a more accurate – and definitely kinder – pseudonym. Solar Lentigo is easy to identify because they are flat, light brown in colour, and well defined on the paler skin surrounding them. Their diameter ranges from 2 to 20mm. Solar Lentigo may occasionally look like a skin cancer, particularly melanoma or IEC.

Author: Our Doctor

Last Modified:    27/9/2019

First published:  28/08/2014