Melanoma vs Non-Melanoma Skin Cancer: What Is the Difference?

In Australia, the most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma and melanoma. Basal cell carcinoma and squamous cell carcinoma are often grouped together as non-melanoma skin cancers, also known as keratinocyte cancers. Melanoma is less common, but it is generally considered more serious because it is more likely to spread to other parts of the body if left untreated.

Non-melanoma skin cancer is a broad term most commonly used to describe basal cell carcinoma and squamous cell carcinoma. These cancers usually develop in the outer layers of the skin and are strongly associated with sun exposure over time.

Although non-melanoma skin cancers are often less likely to spread than melanoma, they should not be ignored. If left untreated, they can continue to grow and may damage surrounding skin and tissue.

Basal cell carcinoma, often called BCC, is the most commonly diagnosed form of skin cancer. It develops from basal cells in the lower part of the epidermis.

A BCC may appear as a:

• pearly, shiny or translucent lump
• pink or pale patch
• sore that does not heal
• flat, scaly area
• small growth that bleeds, crusts or keeps returning

BCCs usually grow slowly and rarely spread to other parts of the body. However, they can still cause local tissue damage, particularly if they are left untreated or occur in delicate areas such as the face, ears, nose or around the eyes. Cancer Council NSW describes common BCC signs as including pink, pearl-like, flat or raised lumps and shiny or scaly areas.

Squamous cell carcinoma, often called SCC, develops from squamous cells in the outer layers of the skin.

An SCC may appear as a:

• firm pink or red lump
• rough, scaly or crusted patch
• tender or bleeding spot
• sore that does not heal
• thickened area of sun-damaged skin

SCCs can grow more quickly than BCCs and have a greater chance of spreading, particularly when treatment is delayed or when they occur in higher-risk areas. Cancer Council NSW notes that SCC may appear as a thick scaly lesion, a fast-growing pink lump, or a red, scaly or crusted spot.

Melanoma develops from melanocytes, the pigment-producing cells that give skin its colour. It may appear as a new spot on the skin or as a change in an existing mole.

Melanoma may be:

• brown, black, pink, red or skin-coloured
• flat or raised
• irregular in shape or border
• changing in size, colour or texture
• different from the other spots on your skin

Melanoma is less common than non-melanoma skin cancer, but it is more likely to spread to other parts of the body. This is why early detection and treatment are so important. Cancer Australia notes that melanoma is more likely to metastasise than basal cell carcinoma or squamous cell carcinoma.

Knowing the difference between melanoma and non-melanoma skin cancer matters because each type can behave differently.

Non-melanoma skin cancers are very common and are often successfully treated when found early. However, they can still cause significant local damage if they are not assessed and managed appropriately.

Melanoma carries a higher risk because it can spread beyond the skin. When melanoma is detected early, treatment is generally more straightforward. When it is detected later, treatment may become more complex.

It is not always possible to tell the difference between a harmless mole, sun damage, non-melanoma skin cancer and early melanoma just by looking at the skin.

Some skin cancers are obvious, but others can be subtle. A spot may look small or relatively harmless on the surface, while important patterns or changes sit beneath what can be seen with the naked eye.

This is where a professional skin check can help. During a skin check, a doctor can use a dermatoscope to examine skin lesions in more detail and identify features that may not be visible without magnification.

Consider booking a skin check if you have a:

• new spot
• mole that is changing in size, shape or colour
• sore that does not heal
• spot that bleeds, crusts or becomes tender
• mole or lesion that looks different from the others
• personal or family history of skin cancer
• history of significant sun exposure

Cancer Council Australia recommends seeing a doctor if you notice a new spot or changes in the size, shape or colour of an existing spot.

Screening frequency is individualised
How often you should have your skin professionally examined depends on your individual risk factors, previous skin cancer history and your doctor’s advice.